Overview of Human Anatomy and Physiology

What's going on all of my healthcare brothers and sisters? I hope that you are having a wonderful day. If you plan on going to any kind of healthcare college or you're going to take your ATITs to get into that college, you're gonna have to know human anatomy and physiology. It's gonna be a little bit of a long video. We're gonna cover all of the body systems you need to know and we're gonna help you pass your tests the first time. Let's get started. So you might be asking yourself, there's so much to know about human anatomy and physiology. Specifically, what do I need to know for this test? Well, you're going to have to know the general orientation of human anatomy, and you're going to have to know the general information about the body system. So that includes respiratory, cardiovascular, digestive, nervous, muscular, reproductive, integumentary, endocrine, urinary, immune, as well as skeletal. Out of the 44 questions that are going to be in this section, 18 of them specifically are about human anatomy physiology. So it's really important to know this information to pass your ATITs. So to begin, we're going to look at anatomical terminology. The ATITs will expect you to be able to identify the position and location of the human body. So common anatomical terminology that you're probably going to see on your exam is cephalic. So that is your head. Cranial refers to your skull. Facial is your face. Frontal, that's like your forehead. Occipital, that's the base of the skull. Temporal, that's your temple area. Orbital or ocular, that's your eyes. Optic, that's your ears. Bucal, your cheek. Nasal, your nose. Oral, your mouth. Mental, that's your chin. Cervical, of course, that's your neck, your cervical spine, right? Sternal, that's your breastbone. That's what we push down on when we do CPR. Thoracic, that's your chest. Mamma are your breasts. Acromial is your shoulder. And then you've got scapular, which is your shoulder blade. Vertebral, that is your spinal column. Lumbar, that's your lower back. Dorsal, that's just your back in general. Axillary, that's your armpit. And then you have brachial, that's your arm. Some more anatomical terminology you need to know is antebrachial, that's your forearm. Carpal is your wrist. Palmer is the actual palm of your hand. Polex, your thumb. Dorsum, the back of your hand. Manual is your hand itself. Digital or phalangeal is your fingers. Abdominal, it's right in the name, right? Abdomen. Umbilical is your navel. Coxa is your hips. Sacral, sacral, I'm sorry, is between your hips. Coccygeal is the actual tailbone. Gluteal is your buttocks. Pelvic is your pelvis. Pubic is the pubis area. Perineal is that area between the anus and the external genitalia. Anguinal is your groin area. Femoral is your thigh. Patella is the front of the knee. And popliteal is the back of the knee. Curial is your shin. Sural is the calf. Pedal is your foot. And tarsal is your ankle. And the last bit of anatomical terminology you'll need to know is digital of the phalange is your toe, pedal is your foot, plantar is the sole of your foot, calcaneal is your heel, tarsal is your ankle, dorsum is the top of your foot, and hallux is your great toe. In addition to the terminology, you're going to need to understand positioning as well as direction. So when you're in... This... when you're studying it's important that you actually understand the standard anatomical positions that we're going to go through right now so the first thing you have is anterior that is towards the front so for example my kneecap is on the anterior side of my leg it's on the back it's on the front Posterior is towards the back. For example, the shoulder blades are located on the posterior side of the body. Next we have superior and inferior. So superior means it's towards the head, right? Superior, inferior, towards the bottom, superior, towards the head. So superior, for example, is the hand is part of my superior extremity. This extremity is higher than my legs. right? Inferior is towards the feet. So for example, the foot is part of the inferior extremity. Superior extremity, inferior extremity are your legs. So next we have medial and lateral. So medial is towards the midline. Think M stands for midline, medial, midline. So if we look at our body, our chest is medial to our arms, right? It's in the middle of our body. Then we have lateral. So lateral is away from the midline. It's further away, lateral, away from the body. So for example, the little toe is lateral to the big toe of the same foot. You see, our big toe is in the midline. Our little toe is on the lateral line. So the last set that we're going to look at is proximal and distal. So when we're looking at proximal, we're looking at being closer to the trunk of the body. So this is your trunk, right? All of this is your trunk of your body. Whereas distal means it's going to be further away from the trunk of the body. So when we're looking at examples for proximal, the proximal end of the femur joins the pelvic bone, right? So that end that connects into our pelvic bone is proximal to the body. Whereas when we're looking at distal and we're trying to figure out what's further away from the trunk, we can absolutely say that our hand is distal to the shoulder, right? The shoulder is closer to the trunk of the body. And our hand is much more distal. It's much further away from the body. Hopefully that clears up some anatomical positions to help you pass your ATITs. And the last piece we're going to look at is common directional terms. So the sagittal plane or median, remember medial, is the vertical plane that divides the body into right and left halves. It goes right down the middle, median. Think of sagittal, median. The frontal plane, okay? the corneal plane is the vertical plane that divides the body into anterior and posterior halves. So think frontal, corneal, front, right? It's going to divide my front from my back. And then lastly the transverse plane or the cross-section. That's the one that is the only one that goes horizontal, right? Everything else goes vertical. This one is going to go horizontal and that's going to divide the body into superior, which is the top half, from the inferior, which is the lower half. Now let's start taking a closer look at our individual systems of the body. We're going to begin by looking at the respiratory system. So what do you need to know about your systems? The big thing you need to know is what is their structure and what is their function. So let's begin with the structure of the respiratory system. So as we know the respiratory system is responsible for taking in oxygen from the environment. and releasing carbon dioxide, which is a byproduct of our metabolism. The structure of the respiratory system includes the nose, the mouth, the throat, the larynx, the trachea, the bronchi, as well as the lungs. So let's take a look at each one of these individually. So to begin with, we have our nose, right? Our nose sits right here up in the front. And that is the external opening to our respiratory system. That's what lets in the oxygen and out that carbon dioxide, right? Within the nose you have nostrils and they lead to the nasal cavity which is divided into two sections by that septum. Next you have your mouth as well as your throat, right? These are big parts of your respiratory system. The throat specifically is the tube that starts behind the nose and goes down into the esophagus. The larynx or the voice box, which is right about here, is located at the top of the trachea. Next underneath that you have the trachea right you have your windpipe that sits right in here and that tube goes from the larynx into your bronchi and then your bronchi are two main tubes that lead from the trachea into the lungs. You have a left and you have a right. Your bronchioles are the smaller tubes that branch off from the bronchi and lead to your alveoli right so you got a little tube here a little tube there a little tube here so on and so forth. And then next you have your alveoli, which are like little sacs that are located at the end of those bronchioles. And that's primarily where that gas exchange takes place. If you see them on any kind of depiction, they look kind of like little great clusters. That's what your alveoli are. And then lastly, you have your lungs. You have your right lung and you have your left lung. The right lung is divided into three sections, whereas your left lung is divided into two sections. Do you know why your left lung has only two sections? It's because that's where your heart sits. Your heart sits right about in here. In order to make room for the heart, your body has done so by removing one of those sections, giving your heart a little bit more room inside your chest cavity. So what is the function of the respiratory system? So the respiratory system, as we said before, is responsible for taking in oxygen and releasing carbon dioxide. When you breathe in or inhale, your diaphragm contracts and moves downwards. This increases the volume within your thoracic cavity and decreases the pressure that's inside it. Oxygen is then pulled in from the atmosphere as well as other elements, but we won't go into those. Oxygen passes from the alveoli into the blood, and as a result, air flows into your lungs. Now, when we breathe out or exhale, your diaphragm relaxes and then it moves back upward. This decreases the volume in your thoracic cavity and increases the pressure inside of it. Carbon dioxide is released from the alveoli into the lungs and that is also known as ventilation, right? We breathe out that carbon dioxide. And as a result, the air flows out of your lungs. The respiratory system is also responsible for maintaining pH that's in the blood. This one's actually pretty cool. When the blood becomes too acidic, the respiratory system kicks into overdrive and removes that excess acid through our respiratory system. This is done by blowing off carbon dioxide, which is considered an acidic gas. So what are some factors that can ultimately affect our respiratory system? Well, number one, there's diseases, right? We have pneumonia, bronchitis, and asthma. All of these can affect the way that we breathe. Asthma is really a common one that you're going to see in a lot of persons that comes to the hospital, and that is because ultimately your airways narrow and it makes it difficult to breathe. Mucus buildup is another issue that can ultimately affect breathing by making it difficult to inhale and exhale out. Smoking cigarettes is also a major factor that can damage the respiratory system, because as we know, cigarette smoke contains a number of harmful chemicals that can ultimately damage the lungs and the airways. Additional factors such as pollution and dust can also affect the system. You know, as the air quality becomes poor, it can irritate the lungs and cause problems with our breathing. And then lastly, allergies and inflammation can play a huge role on the respiratory system. If you have allergies, your airways may become narrowed, right? They become inflamed with all of that inflammation, which can make it more difficult to breathe. And people who experience shortness of breath... wheezing, as well as difficulty breathing, typically have some kind of allergy or some kind of inflammation taking place. Now let's take a closer look at my personal favorite organ, and that is the heart, the cardiovascular system. So when it comes to this particular system, it's really made up of the heart, the blood vessels, and the blood. So let's begin by looking at the heart. So when it comes to our heart, we know that this is that muscular organ that pumps out blood throughout the body. We have four chambers and that includes our right atrium and our left atrium. And then we have our right ventricle and our left ventricle. And of course, we have the septum. That septum is the wall that separates the left and right side of our chambers. So moving on to our blood vessels, these are the tubes that actually carry that blood throughout the body. And there are three major types of blood vessels. We have our arteries, our veins, as well as our capillaries. So when it comes to our arteries, that is the rich oxygen-rich blood that is being carried throughout the heart. While the veins are carrying the oxygen-poor blood, that's our deoxygenated blood, throughout the heart. Once our arteries carries that oxygen-rich blood throughout the body, it gets delivered into our capillaries. And these are those tiny little vessels that connect our arteries to our veins. That's where all of that exchange of nutrients takes place and all of those byproducts are exchanged. And then next we have our blood, right? So that's that liquid that carries the oxygen, the nutrients that goes throughout our body. And then it takes that carbon dioxide and those waste products back from the blood. Once all of that's been collected, it goes back through our veins. So our deoxygenated blood goes back to the veins and back to the heart where all of that exchange again takes place. So we're either breathing out our carbon dioxide or taking in our oxygen. So two common words you're going to hear a lot is systole and diastole, and that's what happens during our cardiac cycle, right? With systole, that is the contraction of the heart, and diastole is when the heart relaxes, okay? So during systole, the blood is being pumped out of the heart and into the arteries. The atrial ventricular valve, that is our mitral and our tricuspid valves, actually close, and that Closing of those valves is what causes that lub sound that you hear first. During diastole, blood is flowing into the heart and filling the chambers. And that's when our semilunar valves, our aortic and our pulmonic valves actually close. And that's when you hear the lub, the dub sound. So during systole, you hear lub. And then during diastole, you hear dub, lub, dub, lub, dub, lub, dub. So next we're going to move on to the heart's electrical system. So we have these nodes or these different pacemakers located throughout the heart that helps let the heart know that it needs to contract. We have the sinoatrial node which is located in the upper right atrium. We have the atrioventricular node which is located at the junction between the atria and the ventricles. We have the bundle of his. And then we have the left and right bundle branches that go between the left and right of the heart, ultimately ending in the Purkinje fibers. So as we know the sinoatrial node is the primary pacemaker of the heart, right? That's what gives us our sinus rhythms and we get those beats that are should be between 60 to 100 beats per minute. If for some reason the sinoatrial node was to give up, the next pacemaker that would kick in would be our atrial node, right? Our atrioventricular node. That is that node that's located right there, kind of at the junction. And with that particular node, it's not going to beat as fast as the sinoatrial node. It's going to beat between 40 to 60 beats per minute. That is what it is preset at in order to pump the heart. Now, if for some reason the sinoatrial node and the atrioventricular node were to give up... The last ditch effort of the heart are the Purkinje fibers, and that is located all the way at the bottom along our ventricular walls. And what the Purkinje fibers beat at is 20 to 40 beats per minute. So these are going to be really, really slow heart rhythms when our sinoatrial node and our atrium ventricular node has ultimately given up. Now let's take a closer look at how blood flows through the cardiovascular system. Something that's important to note is that the cardiovascular system is ultimately a closed system. And this just means that the blood stays within the vessels and don't leak out of those vessels under normal conditions. We understand that damage and things can occur, but under normal conditions, everything stays within this closed system. The heart pumps oxygenated blood through the arteries from the lungs to the left atrium, down into the left ventricle. and out through the aorta to the rest of the body. The blood then flows through the capillaries where it exchanges oxygen and nutrients in the tissues for carbon dioxide and waste. And then the carbon dioxide, waste, and oxygen pore, remember that's that deoxygenated blood, are then transported through the veins back to the heart. The blood enters into the right atrium. and then into the right ventricle and back into the lungs where that carbon dioxide and waste material is released and oxygen is then taken into the red blood cells and the entire process starts all over again with oxygenating the body. Lastly, let's take a closer look at the functions of the cardiovascular system. We've talked about number one way into depth and that is the delivery of oxygen and nutrients to the cells of the body and removing that carbon dioxide and waste. So we won't go further into that. But we will start with number two, which is helping maintain the body's blood pressure. So when it comes to the blood pressure, that is the force of the blood against the walls of the artery. So as you can imagine, if the blood pressure is too high, that means that force is going to be increased and that can ultimately damage the arteries. Whereas if the blood pressure is too low, it's going to cause problems with the blood flow throughout the system. In addition to blood pressure, it also helps with body temperature. So when the body temperature rises, the blood vessels dilate. That means that they widen to allow that heat to escape. But when the body temperature drops, the blood vessels constrict. That means that they start to narrow, and they prevent heat from escaping the body in order to maintain what heat is left in there. The cardiovascular system also helps maintain the body's pH, right? So we have a bicarbonate buffer system that helps maintain acid by removing excess hydrogen ions from the blood. And then lastly there's various other things that the cardiovascular system does. They also transport hormones about throughout the body. They help fight against infections. They also aid in the digestion of food. as well as assist with the repair of damaged tissues. Let's take a closer look at the structure of the digestive system. Yes, we're moving on to the GI. So the digestive system is composed of the GI tract, that's your gastrointestinal tract, as well as accessory organs. So the GI tract is a long continuous tube that starts with the mouth and ends with the anus. The GI tract is divided into the following parts. You have your mouth. your esophagus, your stomach, small intestine, large intestine, as well as your rectum. So let's see how food journeys through this system. So digestion of food truly begins in the mouth, where you chew and you mechanically digest. That's that physical breakdown of food. That's where that mechanical breakdown occurs. Mucus and saliva lubricates the food and enzymes with like things like amylase and lipase and that's what initiates the chemical digestion of starches and lipids the bolus of food that is swallowed then travels down to the pharynx and into the esophagus peristalsis which is the contraction of muscles occur within the esophagus to help move the food down into the stomach now the stomach is shaped kind of like a j-shaped sack And that's where the food is stored. And it again initiates additional chemical digestion with enzymes. Gastric acid kills bacteria, denatures any kind of proteins, and activates those digestive enzymes. In the small intestine, this is the main site of digestion as well as absorption. And that's composed of your duodenum, your jejunum, and your ileum. The small intestine is... coiled and has a series of foldings that increase the surface area for absorption. Next it goes into your large intestine and that is composed of your cecum, your colon, as well as your rectum. And the large intestine absorbs water, electrolytes, and vitamins produced by the enteric bacteria that's located in there. And then lastly your rectum is the final section of the GI tract. And that's where it stores your feces until it's ultimately eliminated through defecation. The accessory organs include your teeth, your tongue, your salivary glands, liver, gallbladder, as well as your pancreas. They all work together to help with the digestion of food. These organs help break down those smaller pieces in the body and also helps absorb nutrients along the way. Lastly, we're going to take a closer look at the enzymes and hormones that are involved in digestion that you'll need to know for your test. Number one is gastrin. Gastrin is the hormone that is produced by the stomach and stimulates the production of stomach acid. Chlocystokinin or CCK is the hormone that is produced by the small intestine and stimulates the release of enzymes from the pancreas and bile from the liver. Saccharin is a hormone that is produced by the small intestine and stimulates the production of bicarbonate. from the liver. Of course we have insulin, our favorite, and that hormone is produced by the pancreas and helps regulate our blood sugar levels. Glucagon, that hormone is produced by the pancreas and helps release glucose from the liver. And then lastly we have bile, and this is the fluid that is produced by the liver and ultimately stored in our gallbladder. Bile breaks down fats that are found within the small intestine. Let's talk about that nervous system. So the division of the nervous system, it is divided into two parts, our central nervous system, as well as our peripheral nervous system. So our central nervous system is composed of our brain and our spinal cord. And this is the central command center where all communication and actions occur in the body. Whereas with our peripheral nervous system, that is composed of nerves that branch off from the spinal cord and innervate the body. This system sends the signals by the brain to targeted locations. The nervous system is ultimately responsible for transmitting signals between the body and the brain. One of the key structures you need to know is the structure of a neuron. This is the basic unit of the nervous system. Neurons are composed of cell bodies, dendrites, and an axon. The cell body contains the nucleus as well as other organelles. The dendrites are short branch-like extensions that generate graded electrical impulses. The axon is that long extension that transmits the signals to another neuron. At the end of the axon there are kind of terminal buttons, which release neurotransmitters called the axon terminal. Myon sheath is that white fatty substance that covers the axon and helps to increase the sp- speed of nerve impulses. And then lastly synapses is the space between the terminal buttons of one neuron and the dendrites of another neuron. So we have a couple different kinds of neurons within our body. We have sensory or afferent neurons and we have motor or efferent neurons. Sensory neurons send messages to the central nervous system. Whereas our motor neurons send messages to our muscles, right? And these can be further broken down into autonomic, also known as involuntary, and somatic voluntary nervous systems. So with our involuntary nervous system, it's responsible for those involuntary actions, such as our heart rate, our digestion, and our respirations. We don't really have any control over those things, right? Whereas our somatic nervous system is responsible for our voluntary actions. And that is the movement of our limbs. Let's get muscular. Let's talk about different types of muscle tissue. So there's three different types. We have skeletal, we have cardiac, and we have smooth. So beginning with skeletal muscle, this is what is attached to bones and is responsible for the movement of our body. Think skeletal movement of the body. These muscles are striated and very strong. The muscles are the only voluntary tissue that's found within the body. Next is our cardiac muscle, and this is of course found within our heart, and that is what helps pump blood throughout the body. These muscles are also striated. Cardiac muscle tissue cannot be consciously controlled, making this muscle involuntary. And then lastly, we have smooth muscle, and that's what's found in the walls of our internal organs such as our stomach, our intestines, as well as our blood vessels. These muscles are not striated. They are the only ones that are not striated and they are of course also involuntary. They cannot be controlled consciously. These muscles are the weakest of all muscle tissue. So what is the function of muscle tissues? Muscle is responsible for the movement of the body. We know that, right? They generate force by contracting and producing movement by moving the bones to which they are attached to. There are over 700 named muscles in the body and it makes up approximately half of our total body weight. So we talked about this a little bit before and that is nerves and muscles work cooperatively to help with muscle movement. Nerves control muscles by sending signals or impulses to the muscles. These impulses causes the muscles to contract and generate force. The nerve impulse originates in the brain, is sent through the spinal cord to the muscle. The message is then sent down to the axon of the nerve of that muscle. And the muscle fiber receives that message and ultimately contracts. So we're going to talk briefly about the reproductive system, but we're not going to get too graphic with it. But these are the things that you're going to need to know. We're going to start with the structures of the male reproductive system. The male reproductive system is made up of the testes, the epidimidus, the vas deferens, the seminal vesicles, the prostate gland, as well as the penis. So the testes are a pair of oval-shaped organs that produce sperm as well as testosterone. The epidimidus is the long, coiled tube that stores and transports the sperm. The vas deferens is a long, thin tube that carries sperm from the epidermis to the seminal vesicles. Those vesicles are a pair of sac-like structures that produce the fluid that helps nourish the sperm. The prostate gland is a small, round organ that produces a fluid that helps transport the sperm. And then lastly, the penis. That's that long cylindrical organ that carries urine as well as sperm outside of the body. So for the female reproductive system, that is made up of ovaries, fallopian tubes, the uterus, vagina, as well as the vulva. So the ovaries is a pair of small oval-shaped organs that produce eggs and hormones. The fallopian tube is a pair of long, thin tubes that carries those eggs from the ovaries to the uterus. The uterus is a pear-shaped organ that houses and protects the developing fetus. The vagina is a long, cylindrical-like organ that carries blood as well as mucosal tissue from the uterus during a woman's monthly period. It also provides a passageway for intercourse and sperm to enter into the uterus and allows passage for vaginal childbirth. The vulva is the external female genitalia and that includes the labia, the clitoris, as well as the urethra. Lastly, you need to understand the relationship between the reproductive system and the endocrine system. There are various hormones that are part of the endocrine system that help control processes within the reproductive system. Let's break each one of these down. You have the gonadotropin-releasing hormone, which is produced by the hypothalamus and stimulates the release of follicle stimulating hormones as well as luteinizing hormones from the pituitary gland. You have the follicle stimulating hormone which helps to stimulate the growth of eggs in the ovaries as well as control the menstrual cycle. Luteinizing hormones help to trigger ovulation and they release an egg from the ovary. Testosterone is a hormone produced by the testes that helps with the production of sperm and development of male characteristics. Unlike in females, sperm is constantly being produced and matured, whereas with females, the egg is only released once a month. Estrogen is a hormone produced by the ovaries to help with the development of female characteristics and regulates the menstrual cycle. So what does this look like in females? In a female reproductive system, the follicle stimulating hormone signals the ovaries to produce more estrogen. Estrogen causes the egg to mature. Luteinizing hormone is released causing the eggs to produce progesterone to prepare the endometrium for implantation. The egg is then released from the ovary and travels down the fallopian tube to the uterus. If the egg is fertilized by sperm, then it will implant itself into the uterus and begin to grow. However, if the egg is not fertilized, then it will begin shedding during menstruation. Let's talk about that good old integumentary system. What is the structure of this system? Well, it's ultimately made up of skin, hair, nails, and our sweat glands. The skin is the largest organ in the body and is made up of three layers. We have the epidermis, the dermis, and the subcutaneous hypodermis. So the epidermis is the outer layer of the skin, and that's what helps with the waterproof barrier, as well as protecting our body from infection. Underneath that, you have your dermis, that's that middle layer of the skin. And this usually contains your blood vessels, nerves, hair follicles, as well as sweat glands. And then lastly, the subcutaneous level, also known as the hypodermis, is the innermost layer of the skin. And that typically contains fat as well as connective tissue. So really, what is the overall function of this system? The integumentary system has several functions, including protection, Regulation of body temperature and sensation. So with protection, the skin protects the body from harmful substances, UV rays, as well as excessive water loss by creating a barrier from outside pathogens. Melanocytes produce melanin that help protect against those ultraviolet radiation rays. Excretion. Excretion is primarily with our sweat glands and that's what helps regulate our... body temperature by producing sweat that evaporates and cools the body. Sweat contains trace amounts of lactic acid, urea, as well as alcohol. And then lastly, sensation. The skin is packed with nerve endings and allows us to touch, feel pressure, heat, as well as cold. So how does the integumentary system help with homeostasis? Well, it helps by regulating the body temperature as well as... fluid balance. When the body becomes too warm, like the guy behind me, the blood vessels in the skin dilate and sweat is produced to help cool the body. If the body becomes too cold, like we talked about before, the blood vessels constrict, they narrow, and the body produces less sweat in order to maintain heat. Moving on to our endocrine system, we got a little bit of an introduction in our other portions of the ATITs exam, human anatomy and physiology, but now we're going to look very specifically at this system, and we're going to begin by looking at the glands. So the endocrine system is made up of a network of glands that produce and secrete hormones. These hormones help regulate many body functions, including growth and development, metabolism, reproduction, and mood. So to begin with, the pituitary gland is the master gland of the endocrine system, and it helps produce growth hormones, prolactin, as well as additional hormones. The thyroid gland produces thyroxine as well as calcitonin. Thyroxine helps regulate our metabolism while calcitonin helps regulate calcium levels in our blood. The parathyroid gland produces parathyroid hormone, which helps with the regulation of calcium levels within the blood. The thymus gland produces thymusin, which helps to develop the immune system. The adrenal gland produces epinephrine as well as norepinephrine, which helps regulate our fight or flight response. The pancreas produces insulin and glucagon, which helps regulate our blood sugar levels. And then lastly, our testes, those produce testosterone, which helps regulate the development of male reproductive organs and secondary sex characteristics. So let's look at the... functions of the endocrine system. We talked about a lot of them before with our growth and development, metabolism, reproduction, as well as mood. With growth and development, growth hormone helps stimulate cell division as well as bone growth. With our metabolism, insulin, for example, helps regulate blood sugar levels. In our reproduction system, estrogen and progesterone help to regulate the menstrual cycle. And then lastly, with our mood, norepinephrine and epinephrine help regulate that fight or flight response that we feel. Many hormones from the endocrine glands have different chemical structures, including lipid-based proteins or lipid-based hormones, nonpolar fat-soluble hormones, as well as water-soluble hormones. So let's break each one of these down. Lipid-based hormones are made up of cholesterol and include testosterone as well as our estrogen. These hormones are insoluble in water and are transported in the blood by carrier proteins. Nonpolar fat soluble hormones are made of amino acids and that includes our thyroid hormones. These hormones are insoluble to water and are transported in the blood again by those carrier proteins. And then lastly, we have water-soluble hormones. These are also made up of amino acids and include things like epinephrine. These hormones are soluble in water and are transported in the blood by diffusion. The last couple topics we're going to look at is homeostasis in the endocrine system, as well as those positive and negative feedback mechanisms. So we talked about homeostasis a little bit before in our previous slide, and that ultimately is maintained by the use of growth and development, metabolism, reproduction, and mood. So I'm not going to go through those again. However, with our positive and negative feedback mechanisms, this is used to maintain homeostasis in the system as well. A positive feedback mechanism is a process that amplifies the change in a given direction. So for example, the release of oxytocin during childbirth is a positive feedback mechanism. that amplifies the change that needs to be given for childbirth. Oxytocin stimulates uterine contractions and causes the fetus to push against and stretch the cervix. Whereas with our negative feedback system, this is a process that reverses the change or tries to slow it down. So for example, the release of insulin in response to high blood sugar levels is a negative feedback mechanism. That is because it can reverse that change or slow down the lowering of the blood sugar levels. We don't want to release too much and then cause us to bottom out with our blood sugar. The pancreas is able to adjust the amount of hormones that is secreted in proportion to the amount of blood glucose that is detected in the blood. Next let's talk about that good old organ, them kidneys. Specifically the urinary system. The urinary system is made up of the kidneys, the renal cortex, our renal medulla, uterus, bladder, and urethra. The kidneys are a pair of organs that help filter blood and produce urine. The renal cortex is the outer layer of the kidneys and contains the renal pyramids and blood vessels. Urethra peritoneum is stimulated in the production of new red blood cells here. The renal medulla is the inner layer of the kidney that helps concentrate the urine. The ureters are a pair of tubes that carry the urine from the kidneys into the bladder. The bladder is that little sack that stores the urine until it is ready to be excreted. And the urethra is the tube that carries the urine from the bladder to the outside of the body. So let's talk about the overall function of the urinary system. The urinary system is really an integral part of the homeostasis within the body. The system helps excrete waste and maintain balance. The structural unit of the kidney is called the nephron. Nephrons are responsible for the filtration of blood by removing waste and reabsorbing water and molecules. The glomerulus is a ball of capillaries that is the site of filtration within the neuron. And the tubule is a tube that leads from the glomerulus to the renal pelvis the tubule is responsible for that reabsorption and secretion what remains from the tubule will be carried into the kidney and drained out from the ureter as always these systems are going to talk to each other right so what is the relationship between the cardiovascular system and the urinary system well the cardiovascular system and the urinary system really work together to again help maintain that homeostasis within the body The cardiovascular system transports blood to the kidneys so that it can be filtered. The urinary system excretes that waste and helps regulate blood pressure by controlling the volume of blood. In turn, the kidneys produce a hormone called erythropoietin that stimulates the production of new red blood cells for the cardiovascular system. So let's talk about our favorite system that helps with our infection rates and that is our immune system. The immune system is made up of innate defense as well as adaptive defense systems. The innate defense system is the body's first line of defense against infections and includes those physical barriers, such as our skin and our mucous membranes, as well as chemical barriers, such as enzymes and stomach acids. The adaptive system is the body's second line of defense and includes the lymphatic system, white blood cells, and antibodies. Ultimately, the immune system protects the bodies from foreign invaders such as bacteria, viruses, and fungi. It does this by recognizing these invaders and producing antibodies to destroy them. The immune system also helps to remove these invaders from the body, and memory T-cells help the body to remember these invaders as they can be destroyed in the future more quickly when they re-enter the body. So let's look at the innate defense system a little bit closer. The innate defense system is the body's first line of defense against infections. And we talked about that. That's the skin and those mucous membranes, as well as those chemical barriers such as enzymes and stomach acids. One of the first responses is called the inflammatory response. This is when blood vessels dilate and white blood cells and fluids are sent to the area of infection. We also have histamines. that are going to be released causing the increase of blood flow to an area and the number of white blood cells to that area is going to be called phagocytes. Those phagocytes destroy the unknown bacteria that's in that area. This response helps remove foreign invaders and begins the healing process within the system. So as always we need to have a secondary defense, right? And that is our adaptive defense system. That includes our lymphatic system, white blood cells, and antibodies. This system functions with the help of antigens. Antigen-presenting cells, helper T cells, cytotoxic T cells, cytokines, antibodies, as well as memory cells. So let's take a closer look at each one of these. Antigens are foreign invaders that the body has been exposed to, such as bacteria and viruses that induce an immune response. Antigen-presenting cells are white blood cells that engulf the foreign invader and present the antigen on its surface. Helper T cells is the type of white blood cells that help activate the other cells within the immune system. The helper T cells induce B cells that secrete a large number of antibodies to bind to that antigen. Cytotoxic T cells are the type of white blood cells that engulf the foreign invader and present the antigen on its surface. I'm sorry, white blood cells that destroy infected cells. Cytokines are chemicals that help to regulate the immune system and activate additional cytotoxic T cells. Next we have antibodies, and these are proteins that attach to the antigen to help destroy them altogether. And then lastly are our memory cells, and these are the white blood cells that remember that specific foreign invader and helps the body to respond more quickly if that invader was to enter the body again. So we have two different types of immunities. We have passive as well as active immunities. So with passive immunity, this is when the body is exposed to antibodies that have been made by another individual, such as a mother passing antibodies from her breast milk to her child. And then we have active immunity, and this is when the body produces its own antibodies in response to an infection. Active immunity is usually longer lasting than that passive immunity because at some point we no longer get that passive immunity right from the mother to the child. But with active immunity, we're always constantly being exposed to things that it is remembering and we're building antibodies against that. So technically our active immunity is always going to last a little bit longer than our passive immunity. So let's move on to our very last one. body system and that is the skeletal system. So really what is the overall structure and function of this system? Well the skeletal system is made up of bones that are connected by joints and the bones are held together at those joints by ligaments. So bones come in four major types. We have long, short, flat, and irregular. So to begin with our long bones these are the bones that are found in our arms and our legs including our humerus, our femur. ulna, radius, tibia, as well as our fibula. They are longer than they are wide and have shafts with two enlarged ends called the proximal and distal ends. Remember proximal is close to the body, right, close to the trunk, and then distal is away, distance, away from the body, away from the trunk. Next we have short bones, and these are bones that are usually found in our wrists as well as our ankles. And these bones usually include our carpals and our tarsals. They are approximately equal in length as well as width. So we have flat bones and these bones are usually found within our ribs, our sternum, our shoulder blades, as well as our hip bones. And these are usually thin and often curved. And then lastly irregular bones. These are the bones that are very irregular and are usually found within our spine. And these include our vertebrae. They have a variety of shapes and they're not symmetrical in any way is why they fit within the irregular bones category. Bones are made of several different types of tissues including compact, spongy, cankulous, as well as trabecular. So with compact bone this is the hard outer layer of bone that provides protection and support. It makes up the shaft of long bones and the flat surfaces of other bones. Spongy bones is very porous. It's lightweight bone. It's found at the ends of long bones as well as vertebrae. Canglis bones is a type of spongy bone that contains small little cavities. There's just a whole bunch of them in there. And then lastly, trabecular bones are the type of spongy bone that kind of has like a honeycomb like structure inside of them. Molds are also made up of marrow, which is a soft tissue that produces blood cells. Brittle bone diseases such as osteogenesis imperfecta results from a mutation in the gene that codes for collagen, which is a protein that is made up of bone tissue. This disease causes bones to be very fragile as well as break very easily. And then lastly, you know I'm all about the relationships between our body systems, and we're going to discuss how the skeletal system has a relationship with the muscular system. So the muscular system provides movement for that skeletal system, and they must work together through communication with the nervous system. The muscle connects to bones with tendons, which is comprised of connective tissues. So for example, the bicep brachii is the muscle of the upper arm that attaches to the shoulder bone with tendons. The bicep brachii contracts to lift the arm. I hope that this information was helpful in understanding what you need to know for the human and anatomy portion of the ATITs. If you have any additional questions, make sure that you leave them down below. I love answering your questions. Head over to www.nursechung.com where there's additional resources on all topics and all things regarding the ATITs. And as always, I will see you in the next video. Bye!

We're gonna cover all of the body systems you need to know and we're gonna help you pass your tests the first time. Let's get started. So you might be asking yourself, there's so much to know about human anatomy and physiology. Specifically, what do I need to know for this test? Well, you're going to have to know the general orientation of human anatomy, and you're going to have to know the general information about the body system.

So that includes respiratory, cardiovascular, digestive, nervous, muscular, reproductive, integumentary, endocrine, urinary, immune, as well as skeletal. Out of the 44 questions that are going to be in this section, 18 of them specifically are about human anatomy physiology. So it's really important to know this information to pass your ATITs. So to begin, we're going to look at anatomical terminology.

The ATITs will expect you to be able to identify the position and location of the human body. So common anatomical terminology that you're probably going to see on your exam is cephalic. So that is your head. Cranial refers to your skull. Facial is your face.

Frontal, that's like your forehead. Occipital, that's the base of the skull. Temporal, that's your temple area. Orbital or ocular, that's your eyes. Optic, that's your ears.

Bucal, your cheek. Nasal, your nose. Oral, your mouth.

Mental, that's your chin. Cervical, of course, that's your neck, your cervical spine, right? Sternal, that's your breastbone.

That's what we push down on when we do CPR. Thoracic, that's your chest. Mamma are your breasts.

Acromial is your shoulder. And then you've got scapular, which is your shoulder blade. Vertebral, that is your spinal column.

Lumbar, that's your lower back. Dorsal, that's just your back in general. Axillary, that's your armpit.

And then you have brachial, that's your arm. Some more anatomical terminology you need to know is antebrachial, that's your forearm. Carpal is your wrist. Palmer is the actual palm of your hand. Polex, your thumb.

Dorsum, the back of your hand. Manual is your hand itself. Digital or phalangeal is your fingers.

Abdominal, it's right in the name, right? Abdomen. Umbilical is your navel. Coxa is your hips.

Sacral, sacral, I'm sorry, is between your hips. Coccygeal is the actual tailbone. Gluteal is your buttocks. Pelvic is your pelvis.

Pubic is the pubis area. Perineal is that area between the anus and the external genitalia. Anguinal is your groin area. Femoral is your thigh. Patella is the front of the knee.

And popliteal is the back of the knee. Curial is your shin. Sural is the calf.

Pedal is your foot. And tarsal is your ankle. And the last bit of anatomical terminology you'll need to know is digital of the phalange is your toe, pedal is your foot, plantar is the sole of your foot, calcaneal is your heel, tarsal is your ankle, dorsum is the top of your foot, and hallux is your great toe. In addition to the terminology, you're going to need to understand positioning as well as direction. So when you're in...

This... when you're studying it's important that you actually understand the standard anatomical positions that we're going to go through right now so the first thing you have is anterior that is towards the front so for example my kneecap is on the anterior side of my leg it's on the back it's on the front Posterior is towards the back. For example, the shoulder blades are located on the posterior side of the body. Next we have superior and inferior. So superior means it's towards the head, right?

Superior, inferior, towards the bottom, superior, towards the head. So superior, for example, is the hand is part of my superior extremity. This extremity is higher than my legs.

right? Inferior is towards the feet. So for example, the foot is part of the inferior extremity.

Superior extremity, inferior extremity are your legs. So next we have medial and lateral. So medial is towards the midline. Think M stands for midline, medial, midline.

So if we look at our body, our chest is medial to our arms, right? It's in the middle of our body. Then we have lateral. So lateral is away from the midline.

It's further away, lateral, away from the body. So for example, the little toe is lateral to the big toe of the same foot. You see, our big toe is in the midline.

Our little toe is on the lateral line. So the last set that we're going to look at is proximal and distal. So when we're looking at proximal, we're looking at being closer to the trunk of the body. So this is your trunk, right?

All of this is your trunk of your body. Whereas distal means it's going to be further away from the trunk of the body. So when we're looking at examples for proximal, the proximal end of the femur joins the pelvic bone, right? So that end that connects into our pelvic bone is proximal to the body. Whereas when we're looking at distal and we're trying to figure out what's further away from the trunk, we can absolutely say that our hand is distal to the shoulder, right?

The shoulder is closer to the trunk of the body. And our hand is much more distal. It's much further away from the body. Hopefully that clears up some anatomical positions to help you pass your ATITs.

And the last piece we're going to look at is common directional terms. So the sagittal plane or median, remember medial, is the vertical plane that divides the body into right and left halves. It goes right down the middle, median. Think of sagittal, median. The frontal plane, okay?

the corneal plane is the vertical plane that divides the body into anterior and posterior halves. So think frontal, corneal, front, right? It's going to divide my front from my back.

And then lastly the transverse plane or the cross-section. That's the one that is the only one that goes horizontal, right? Everything else goes vertical. This one is going to go horizontal and that's going to divide the body into superior, which is the top half, from the inferior, which is the lower half.

Now let's start taking a closer look at our individual systems of the body. We're going to begin by looking at the respiratory system. So what do you need to know about your systems?

The big thing you need to know is what is their structure and what is their function. So let's begin with the structure of the respiratory system. So as we know the respiratory system is responsible for taking in oxygen from the environment. and releasing carbon dioxide, which is a byproduct of our metabolism.

The structure of the respiratory system includes the nose, the mouth, the throat, the larynx, the trachea, the bronchi, as well as the lungs. So let's take a look at each one of these individually. So to begin with, we have our nose, right?

Our nose sits right here up in the front. And that is the external opening to our respiratory system. That's what lets in the oxygen and out that carbon dioxide, right? Within the nose you have nostrils and they lead to the nasal cavity which is divided into two sections by that septum.

Next you have your mouth as well as your throat, right? These are big parts of your respiratory system. The throat specifically is the tube that starts behind the nose and goes down into the esophagus.

The larynx or the voice box, which is right about here, is located at the top of the trachea. Next underneath that you have the trachea right you have your windpipe that sits right in here and that tube goes from the larynx into your bronchi and then your bronchi are two main tubes that lead from the trachea into the lungs. You have a left and you have a right.

Your bronchioles are the smaller tubes that branch off from the bronchi and lead to your alveoli right so you got a little tube here a little tube there a little tube here so on and so forth. And then next you have your alveoli, which are like little sacs that are located at the end of those bronchioles. And that's primarily where that gas exchange takes place.

If you see them on any kind of depiction, they look kind of like little great clusters. That's what your alveoli are. And then lastly, you have your lungs. You have your right lung and you have your left lung.

The right lung is divided into three sections, whereas your left lung is divided into two sections. Do you know why your left lung has only two sections? It's because that's where your heart sits. Your heart sits right about in here.

In order to make room for the heart, your body has done so by removing one of those sections, giving your heart a little bit more room inside your chest cavity. So what is the function of the respiratory system? So the respiratory system, as we said before, is responsible for taking in oxygen and releasing carbon dioxide. When you breathe in or inhale, your diaphragm contracts and moves downwards. This increases the volume within your thoracic cavity and decreases the pressure that's inside it.

Oxygen is then pulled in from the atmosphere as well as other elements, but we won't go into those. Oxygen passes from the alveoli into the blood, and as a result, air flows into your lungs. Now, when we breathe out or exhale, your diaphragm relaxes and then it moves back upward. This decreases the volume in your thoracic cavity and increases the pressure inside of it.

Carbon dioxide is released from the alveoli into the lungs and that is also known as ventilation, right? We breathe out that carbon dioxide. And as a result, the air flows out of your lungs. The respiratory system is also responsible for maintaining pH that's in the blood.

This one's actually pretty cool. When the blood becomes too acidic, the respiratory system kicks into overdrive and removes that excess acid through our respiratory system. This is done by blowing off carbon dioxide, which is considered an acidic gas. So what are some factors that can ultimately affect our respiratory system?

Well, number one, there's diseases, right? We have pneumonia, bronchitis, and asthma. All of these can affect the way that we breathe.

Asthma is really a common one that you're going to see in a lot of persons that comes to the hospital, and that is because ultimately your airways narrow and it makes it difficult to breathe. Mucus buildup is another issue that can ultimately affect breathing by making it difficult to inhale and exhale out. Smoking cigarettes is also a major factor that can damage the respiratory system, because as we know, cigarette smoke contains a number of harmful chemicals that can ultimately damage the lungs and the airways. Additional factors such as pollution and dust can also affect the system. You know, as the air quality becomes poor, it can irritate the lungs and cause problems with our breathing.

And then lastly, allergies and inflammation can play a huge role on the respiratory system. If you have allergies, your airways may become narrowed, right? They become inflamed with all of that inflammation, which can make it more difficult to breathe. And people who experience shortness of breath...

wheezing, as well as difficulty breathing, typically have some kind of allergy or some kind of inflammation taking place. Now let's take a closer look at my personal favorite organ, and that is the heart, the cardiovascular system. So when it comes to this particular system, it's really made up of the heart, the blood vessels, and the blood. So let's begin by looking at the heart.

So when it comes to our heart, we know that this is that muscular organ that pumps out blood throughout the body. We have four chambers and that includes our right atrium and our left atrium. And then we have our right ventricle and our left ventricle. And of course, we have the septum.

That septum is the wall that separates the left and right side of our chambers. So moving on to our blood vessels, these are the tubes that actually carry that blood throughout the body. And there are three major types of blood vessels.

We have our arteries, our veins, as well as our capillaries. So when it comes to our arteries, that is the rich oxygen-rich blood that is being carried throughout the heart. While the veins are carrying the oxygen-poor blood, that's our deoxygenated blood, throughout the heart. Once our arteries carries that oxygen-rich blood throughout the body, it gets delivered into our capillaries.

And these are those tiny little vessels that connect our arteries to our veins. That's where all of that exchange of nutrients takes place and all of those byproducts are exchanged. And then next we have our blood, right? So that's that liquid that carries the oxygen, the nutrients that goes throughout our body.

And then it takes that carbon dioxide and those waste products back from the blood. Once all of that's been collected, it goes back through our veins. So our deoxygenated blood goes back to the veins and back to the heart where all of that exchange again takes place.

So we're either breathing out our carbon dioxide or taking in our oxygen. So two common words you're going to hear a lot is systole and diastole, and that's what happens during our cardiac cycle, right? With systole, that is the contraction of the heart, and diastole is when the heart relaxes, okay? So during systole, the blood is being pumped out of the heart and into the arteries. The atrial ventricular valve, that is our mitral and our tricuspid valves, actually close, and that Closing of those valves is what causes that lub sound that you hear first.

During diastole, blood is flowing into the heart and filling the chambers. And that's when our semilunar valves, our aortic and our pulmonic valves actually close. And that's when you hear the lub, the dub sound.

So during systole, you hear lub. And then during diastole, you hear dub, lub, dub, lub, dub, lub, dub. So next we're going to move on to the heart's electrical system.

So we have these nodes or these different pacemakers located throughout the heart that helps let the heart know that it needs to contract. We have the sinoatrial node which is located in the upper right atrium. We have the atrioventricular node which is located at the junction between the atria and the ventricles. We have the bundle of his.

And then we have the left and right bundle branches that go between the left and right of the heart, ultimately ending in the Purkinje fibers. So as we know the sinoatrial node is the primary pacemaker of the heart, right? That's what gives us our sinus rhythms and we get those beats that are should be between 60 to 100 beats per minute.

If for some reason the sinoatrial node was to give up, the next pacemaker that would kick in would be our atrial node, right? Our atrioventricular node. That is that node that's located right there, kind of at the junction. And with that particular node, it's not going to beat as fast as the sinoatrial node. It's going to beat between 40 to 60 beats per minute.

That is what it is preset at in order to pump the heart. Now, if for some reason the sinoatrial node and the atrioventricular node were to give up... The last ditch effort of the heart are the Purkinje fibers, and that is located all the way at the bottom along our ventricular walls. And what the Purkinje fibers beat at is 20 to 40 beats per minute. So these are going to be really, really slow heart rhythms when our sinoatrial node and our atrium ventricular node has ultimately given up.

Now let's take a closer look at how blood flows through the cardiovascular system. Something that's important to note is that the cardiovascular system is ultimately a closed system. And this just means that the blood stays within the vessels and don't leak out of those vessels under normal conditions. We understand that damage and things can occur, but under normal conditions, everything stays within this closed system. The heart pumps oxygenated blood through the arteries from the lungs to the left atrium, down into the left ventricle.

and out through the aorta to the rest of the body. The blood then flows through the capillaries where it exchanges oxygen and nutrients in the tissues for carbon dioxide and waste. And then the carbon dioxide, waste, and oxygen pore, remember that's that deoxygenated blood, are then transported through the veins back to the heart. The blood enters into the right atrium.

and then into the right ventricle and back into the lungs where that carbon dioxide and waste material is released and oxygen is then taken into the red blood cells and the entire process starts all over again with oxygenating the body. Lastly, let's take a closer look at the functions of the cardiovascular system. We've talked about number one way into depth and that is the delivery of oxygen and nutrients to the cells of the body and removing that carbon dioxide and waste. So we won't go further into that.

But we will start with number two, which is helping maintain the body's blood pressure. So when it comes to the blood pressure, that is the force of the blood against the walls of the artery. So as you can imagine, if the blood pressure is too high, that means that force is going to be increased and that can ultimately damage the arteries. Whereas if the blood pressure is too low, it's going to cause problems with the blood flow throughout the system.

In addition to blood pressure, it also helps with body temperature. So when the body temperature rises, the blood vessels dilate. That means that they widen to allow that heat to escape. But when the body temperature drops, the blood vessels constrict. That means that they start to narrow, and they prevent heat from escaping the body in order to maintain what heat is left in there.

The cardiovascular system also helps maintain the body's pH, right? So we have a bicarbonate buffer system that helps maintain acid by removing excess hydrogen ions from the blood. And then lastly there's various other things that the cardiovascular system does. They also transport hormones about throughout the body.

They help fight against infections. They also aid in the digestion of food. as well as assist with the repair of damaged tissues.

Let's take a closer look at the structure of the digestive system. Yes, we're moving on to the GI. So the digestive system is composed of the GI tract, that's your gastrointestinal tract, as well as accessory organs.

So the GI tract is a long continuous tube that starts with the mouth and ends with the anus. The GI tract is divided into the following parts. You have your mouth. your esophagus, your stomach, small intestine, large intestine, as well as your rectum. So let's see how food journeys through this system.

So digestion of food truly begins in the mouth, where you chew and you mechanically digest. That's that physical breakdown of food. That's where that mechanical breakdown occurs.

Mucus and saliva lubricates the food and enzymes with like things like amylase and lipase and that's what initiates the chemical digestion of starches and lipids the bolus of food that is swallowed then travels down to the pharynx and into the esophagus peristalsis which is the contraction of muscles occur within the esophagus to help move the food down into the stomach now the stomach is shaped kind of like a j-shaped sack And that's where the food is stored. And it again initiates additional chemical digestion with enzymes. Gastric acid kills bacteria, denatures any kind of proteins, and activates those digestive enzymes.

In the small intestine, this is the main site of digestion as well as absorption. And that's composed of your duodenum, your jejunum, and your ileum. The small intestine is... coiled and has a series of foldings that increase the surface area for absorption. Next it goes into your large intestine and that is composed of your cecum, your colon, as well as your rectum.

And the large intestine absorbs water, electrolytes, and vitamins produced by the enteric bacteria that's located in there. And then lastly your rectum is the final section of the GI tract. And that's where it stores your feces until it's ultimately eliminated through defecation. The accessory organs include your teeth, your tongue, your salivary glands, liver, gallbladder, as well as your pancreas. They all work together to help with the digestion of food.

These organs help break down those smaller pieces in the body and also helps absorb nutrients along the way. Lastly, we're going to take a closer look at the enzymes and hormones that are involved in digestion that you'll need to know for your test. Number one is gastrin. Gastrin is the hormone that is produced by the stomach and stimulates the production of stomach acid.

Chlocystokinin or CCK is the hormone that is produced by the small intestine and stimulates the release of enzymes from the pancreas and bile from the liver. Saccharin is a hormone that is produced by the small intestine and stimulates the production of bicarbonate. from the liver. Of course we have insulin, our favorite, and that hormone is produced by the pancreas and helps regulate our blood sugar levels.

Glucagon, that hormone is produced by the pancreas and helps release glucose from the liver. And then lastly we have bile, and this is the fluid that is produced by the liver and ultimately stored in our gallbladder. Bile breaks down fats that are found within the small intestine. Let's talk about that nervous system. So the division of the nervous system, it is divided into two parts, our central nervous system, as well as our peripheral nervous system.

So our central nervous system is composed of our brain and our spinal cord. And this is the central command center where all communication and actions occur in the body. Whereas with our peripheral nervous system, that is composed of nerves that branch off from the spinal cord and innervate the body. This system sends the signals by the brain to targeted locations. The nervous system is ultimately responsible for transmitting signals between the body and the brain.

One of the key structures you need to know is the structure of a neuron. This is the basic unit of the nervous system. Neurons are composed of cell bodies, dendrites, and an axon.

The cell body contains the nucleus as well as other organelles. The dendrites are short branch-like extensions that generate graded electrical impulses. The axon is that long extension that transmits the signals to another neuron.

At the end of the axon there are kind of terminal buttons, which release neurotransmitters called the axon terminal. Myon sheath is that white fatty substance that covers the axon and helps to increase the sp- speed of nerve impulses. And then lastly synapses is the space between the terminal buttons of one neuron and the dendrites of another neuron. So we have a couple different kinds of neurons within our body. We have sensory or afferent neurons and we have motor or efferent neurons.

Sensory neurons send messages to the central nervous system. Whereas our motor neurons send messages to our muscles, right? And these can be further broken down into autonomic, also known as involuntary, and somatic voluntary nervous systems.

So with our involuntary nervous system, it's responsible for those involuntary actions, such as our heart rate, our digestion, and our respirations. We don't really have any control over those things, right? Whereas our somatic nervous system is responsible for our voluntary actions.

And that is the movement of our limbs. Let's get muscular. Let's talk about different types of muscle tissue. So there's three different types. We have skeletal, we have cardiac, and we have smooth.

So beginning with skeletal muscle, this is what is attached to bones and is responsible for the movement of our body. Think skeletal movement of the body. These muscles are striated and very strong.

The muscles are the only voluntary tissue that's found within the body. Next is our cardiac muscle, and this is of course found within our heart, and that is what helps pump blood throughout the body. These muscles are also striated. Cardiac muscle tissue cannot be consciously controlled, making this muscle involuntary.

And then lastly, we have smooth muscle, and that's what's found in the walls of our internal organs such as our stomach, our intestines, as well as our blood vessels. These muscles are not striated. They are the only ones that are not striated and they are of course also involuntary.

They cannot be controlled consciously. These muscles are the weakest of all muscle tissue. So what is the function of muscle tissues?

Muscle is responsible for the movement of the body. We know that, right? They generate force by contracting and producing movement by moving the bones to which they are attached to.

There are over 700 named muscles in the body and it makes up approximately half of our total body weight. So we talked about this a little bit before and that is nerves and muscles work cooperatively to help with muscle movement. Nerves control muscles by sending signals or impulses to the muscles.

These impulses causes the muscles to contract and generate force. The nerve impulse originates in the brain, is sent through the spinal cord to the muscle. The message is then sent down to the axon of the nerve of that muscle.

And the muscle fiber receives that message and ultimately contracts. So we're going to talk briefly about the reproductive system, but we're not going to get too graphic with it. But these are the things that you're going to need to know. We're going to start with the structures of the male reproductive system. The male reproductive system is made up of the testes, the epidimidus, the vas deferens, the seminal vesicles, the prostate gland, as well as the penis.

So the testes are a pair of oval-shaped organs that produce sperm as well as testosterone. The epidimidus is the long, coiled tube that stores and transports the sperm. The vas deferens is a long, thin tube that carries sperm from the epidermis to the seminal vesicles. Those vesicles are a pair of sac-like structures that produce the fluid that helps nourish the sperm.

The prostate gland is a small, round organ that produces a fluid that helps transport the sperm. And then lastly, the penis. That's that long cylindrical organ that carries urine as well as sperm outside of the body. So for the female reproductive system, that is made up of ovaries, fallopian tubes, the uterus, vagina, as well as the vulva.

So the ovaries is a pair of small oval-shaped organs that produce eggs and hormones. The fallopian tube is a pair of long, thin tubes that carries those eggs from the ovaries to the uterus. The uterus is a pear-shaped organ that houses and protects the developing fetus.

The vagina is a long, cylindrical-like organ that carries blood as well as mucosal tissue from the uterus during a woman's monthly period. It also provides a passageway for intercourse and sperm to enter into the uterus and allows passage for vaginal childbirth. The vulva is the external female genitalia and that includes the labia, the clitoris, as well as the urethra.

Lastly, you need to understand the relationship between the reproductive system and the endocrine system. There are various hormones that are part of the endocrine system that help control processes within the reproductive system. Let's break each one of these down.

You have the gonadotropin-releasing hormone, which is produced by the hypothalamus and stimulates the release of follicle stimulating hormones as well as luteinizing hormones from the pituitary gland. You have the follicle stimulating hormone which helps to stimulate the growth of eggs in the ovaries as well as control the menstrual cycle. Luteinizing hormones help to trigger ovulation and they release an egg from the ovary. Testosterone is a hormone produced by the testes that helps with the production of sperm and development of male characteristics.

Unlike in females, sperm is constantly being produced and matured, whereas with females, the egg is only released once a month. Estrogen is a hormone produced by the ovaries to help with the development of female characteristics and regulates the menstrual cycle. So what does this look like in females?

In a female reproductive system, the follicle stimulating hormone signals the ovaries to produce more estrogen. Estrogen causes the egg to mature. Luteinizing hormone is released causing the eggs to produce progesterone to prepare the endometrium for implantation.

The egg is then released from the ovary and travels down the fallopian tube to the uterus. If the egg is fertilized by sperm, then it will implant itself into the uterus and begin to grow. However, if the egg is not fertilized, then it will begin shedding during menstruation. Let's talk about that good old integumentary system. What is the structure of this system?

Well, it's ultimately made up of skin, hair, nails, and our sweat glands. The skin is the largest organ in the body and is made up of three layers. We have the epidermis, the dermis, and the subcutaneous hypodermis. So the epidermis is the outer layer of the skin, and that's what helps with the waterproof barrier, as well as protecting our body from infection.

Underneath that, you have your dermis, that's that middle layer of the skin. And this usually contains your blood vessels, nerves, hair follicles, as well as sweat glands. And then lastly, the subcutaneous level, also known as the hypodermis, is the innermost layer of the skin. And that typically contains fat as well as connective tissue.

So really, what is the overall function of this system? The integumentary system has several functions, including protection, Regulation of body temperature and sensation. So with protection, the skin protects the body from harmful substances, UV rays, as well as excessive water loss by creating a barrier from outside pathogens.

Melanocytes produce melanin that help protect against those ultraviolet radiation rays. Excretion. Excretion is primarily with our sweat glands and that's what helps regulate our...

body temperature by producing sweat that evaporates and cools the body. Sweat contains trace amounts of lactic acid, urea, as well as alcohol. And then lastly, sensation.

The skin is packed with nerve endings and allows us to touch, feel pressure, heat, as well as cold. So how does the integumentary system help with homeostasis? Well, it helps by regulating the body temperature as well as...

fluid balance. When the body becomes too warm, like the guy behind me, the blood vessels in the skin dilate and sweat is produced to help cool the body. If the body becomes too cold, like we talked about before, the blood vessels constrict, they narrow, and the body produces less sweat in order to maintain heat. Moving on to our endocrine system, we got a little bit of an introduction in our other portions of the ATITs exam, human anatomy and physiology, but now we're going to look very specifically at this system, and we're going to begin by looking at the glands. So the endocrine system is made up of a network of glands that produce and secrete hormones.

These hormones help regulate many body functions, including growth and development, metabolism, reproduction, and mood. So to begin with, the pituitary gland is the master gland of the endocrine system, and it helps produce growth hormones, prolactin, as well as additional hormones. The thyroid gland produces thyroxine as well as calcitonin.

Thyroxine helps regulate our metabolism while calcitonin helps regulate calcium levels in our blood. The parathyroid gland produces parathyroid hormone, which helps with the regulation of calcium levels within the blood. The thymus gland produces thymusin, which helps to develop the immune system. The adrenal gland produces epinephrine as well as norepinephrine, which helps regulate our fight or flight response. The pancreas produces insulin and glucagon, which helps regulate our blood sugar levels.

And then lastly, our testes, those produce testosterone, which helps regulate the development of male reproductive organs and secondary sex characteristics. So let's look at the... functions of the endocrine system. We talked about a lot of them before with our growth and development, metabolism, reproduction, as well as mood.

With growth and development, growth hormone helps stimulate cell division as well as bone growth. With our metabolism, insulin, for example, helps regulate blood sugar levels. In our reproduction system, estrogen and progesterone help to regulate the menstrual cycle. And then lastly, with our mood, norepinephrine and epinephrine help regulate that fight or flight response that we feel.

Many hormones from the endocrine glands have different chemical structures, including lipid-based proteins or lipid-based hormones, nonpolar fat-soluble hormones, as well as water-soluble hormones. So let's break each one of these down. Lipid-based hormones are made up of cholesterol and include testosterone as well as our estrogen.

These hormones are insoluble in water and are transported in the blood by carrier proteins. Nonpolar fat soluble hormones are made of amino acids and that includes our thyroid hormones. These hormones are insoluble to water and are transported in the blood again by those carrier proteins.

And then lastly, we have water-soluble hormones. These are also made up of amino acids and include things like epinephrine. These hormones are soluble in water and are transported in the blood by diffusion.

The last couple topics we're going to look at is homeostasis in the endocrine system, as well as those positive and negative feedback mechanisms. So we talked about homeostasis a little bit before in our previous slide, and that ultimately is maintained by the use of growth and development, metabolism, reproduction, and mood. So I'm not going to go through those again.

However, with our positive and negative feedback mechanisms, this is used to maintain homeostasis in the system as well. A positive feedback mechanism is a process that amplifies the change in a given direction. So for example, the release of oxytocin during childbirth is a positive feedback mechanism. that amplifies the change that needs to be given for childbirth. Oxytocin stimulates uterine contractions and causes the fetus to push against and stretch the cervix.

Whereas with our negative feedback system, this is a process that reverses the change or tries to slow it down. So for example, the release of insulin in response to high blood sugar levels is a negative feedback mechanism. That is because it can reverse that change or slow down the lowering of the blood sugar levels.

We don't want to release too much and then cause us to bottom out with our blood sugar. The pancreas is able to adjust the amount of hormones that is secreted in proportion to the amount of blood glucose that is detected in the blood. Next let's talk about that good old organ, them kidneys. Specifically the urinary system.

The urinary system is made up of the kidneys, the renal cortex, our renal medulla, uterus, bladder, and urethra. The kidneys are a pair of organs that help filter blood and produce urine. The renal cortex is the outer layer of the kidneys and contains the renal pyramids and blood vessels. Urethra peritoneum is stimulated in the production of new red blood cells here.

The renal medulla is the inner layer of the kidney that helps concentrate the urine. The ureters are a pair of tubes that carry the urine from the kidneys into the bladder. The bladder is that little sack that stores the urine until it is ready to be excreted.

And the urethra is the tube that carries the urine from the bladder to the outside of the body. So let's talk about the overall function of the urinary system. The urinary system is really an integral part of the homeostasis within the body. The system helps excrete waste and maintain balance.

The structural unit of the kidney is called the nephron. Nephrons are responsible for the filtration of blood by removing waste and reabsorbing water and molecules. The glomerulus is a ball of capillaries that is the site of filtration within the neuron. And the tubule is a tube that leads from the glomerulus to the renal pelvis the tubule is responsible for that reabsorption and secretion what remains from the tubule will be carried into the kidney and drained out from the ureter as always these systems are going to talk to each other right so what is the relationship between the cardiovascular system and the urinary system well the cardiovascular system and the urinary system really work together to again help maintain that homeostasis within the body The cardiovascular system transports blood to the kidneys so that it can be filtered.

The urinary system excretes that waste and helps regulate blood pressure by controlling the volume of blood. In turn, the kidneys produce a hormone called erythropoietin that stimulates the production of new red blood cells for the cardiovascular system. So let's talk about our favorite system that helps with our infection rates and that is our immune system. The immune system is made up of innate defense as well as adaptive defense systems. The innate defense system is the body's first line of defense against infections and includes those physical barriers, such as our skin and our mucous membranes, as well as chemical barriers, such as enzymes and stomach acids.

The adaptive system is the body's second line of defense and includes the lymphatic system, white blood cells, and antibodies. Ultimately, the immune system protects the bodies from foreign invaders such as bacteria, viruses, and fungi. It does this by recognizing these invaders and producing antibodies to destroy them.

The immune system also helps to remove these invaders from the body, and memory T-cells help the body to remember these invaders as they can be destroyed in the future more quickly when they re-enter the body. So let's look at the innate defense system a little bit closer. The innate defense system is the body's first line of defense against infections.

And we talked about that. That's the skin and those mucous membranes, as well as those chemical barriers such as enzymes and stomach acids. One of the first responses is called the inflammatory response.

This is when blood vessels dilate and white blood cells and fluids are sent to the area of infection. We also have histamines. that are going to be released causing the increase of blood flow to an area and the number of white blood cells to that area is going to be called phagocytes.

Those phagocytes destroy the unknown bacteria that's in that area. This response helps remove foreign invaders and begins the healing process within the system. So as always we need to have a secondary defense, right?

And that is our adaptive defense system. That includes our lymphatic system, white blood cells, and antibodies. This system functions with the help of antigens. Antigen-presenting cells, helper T cells, cytotoxic T cells, cytokines, antibodies, as well as memory cells. So let's take a closer look at each one of these.

Antigens are foreign invaders that the body has been exposed to, such as bacteria and viruses that induce an immune response. Antigen-presenting cells are white blood cells that engulf the foreign invader and present the antigen on its surface. Helper T cells is the type of white blood cells that help activate the other cells within the immune system. The helper T cells induce B cells that secrete a large number of antibodies to bind to that antigen.

Cytotoxic T cells are the type of white blood cells that engulf the foreign invader and present the antigen on its surface. I'm sorry, white blood cells that destroy infected cells. Cytokines are chemicals that help to regulate the immune system and activate additional cytotoxic T cells.

Next we have antibodies, and these are proteins that attach to the antigen to help destroy them altogether. And then lastly are our memory cells, and these are the white blood cells that remember that specific foreign invader and helps the body to respond more quickly if that invader was to enter the body again. So we have two different types of immunities. We have passive as well as active immunities. So with passive immunity, this is when the body is exposed to antibodies that have been made by another individual, such as a mother passing antibodies from her breast milk to her child.

And then we have active immunity, and this is when the body produces its own antibodies in response to an infection. Active immunity is usually longer lasting than that passive immunity because at some point we no longer get that passive immunity right from the mother to the child. But with active immunity, we're always constantly being exposed to things that it is remembering and we're building antibodies against that.

So technically our active immunity is always going to last a little bit longer than our passive immunity. So let's move on to our very last one. body system and that is the skeletal system.

So really what is the overall structure and function of this system? Well the skeletal system is made up of bones that are connected by joints and the bones are held together at those joints by ligaments. So bones come in four major types. We have long, short, flat, and irregular. So to begin with our long bones these are the bones that are found in our arms and our legs including our humerus, our femur.

ulna, radius, tibia, as well as our fibula. They are longer than they are wide and have shafts with two enlarged ends called the proximal and distal ends. Remember proximal is close to the body, right, close to the trunk, and then distal is away, distance, away from the body, away from the trunk.

Next we have short bones, and these are bones that are usually found in our wrists as well as our ankles. And these bones usually include our carpals and our tarsals. They are approximately equal in length as well as width. So we have flat bones and these bones are usually found within our ribs, our sternum, our shoulder blades, as well as our hip bones.

And these are usually thin and often curved. And then lastly irregular bones. These are the bones that are very irregular and are usually found within our spine.

And these include our vertebrae. They have a variety of shapes and they're not symmetrical in any way is why they fit within the irregular bones category. Bones are made of several different types of tissues including compact, spongy, cankulous, as well as trabecular. So with compact bone this is the hard outer layer of bone that provides protection and support.

It makes up the shaft of long bones and the flat surfaces of other bones. Spongy bones is very porous. It's lightweight bone.

It's found at the ends of long bones as well as vertebrae. Canglis bones is a type of spongy bone that contains small little cavities. There's just a whole bunch of them in there.

And then lastly, trabecular bones are the type of spongy bone that kind of has like a honeycomb like structure inside of them. Molds are also made up of marrow, which is a soft tissue that produces blood cells. Brittle bone diseases such as osteogenesis imperfecta results from a mutation in the gene that codes for collagen, which is a protein that is made up of bone tissue.

This disease causes bones to be very fragile as well as break very easily. And then lastly, you know I'm all about the relationships between our body systems, and we're going to discuss how the skeletal system has a relationship with the muscular system. So the muscular system provides movement for that skeletal system, and they must work together through communication with the nervous system. The muscle connects to bones with tendons, which is comprised of connective tissues. So for example, the bicep brachii is the muscle of the upper arm that attaches to the shoulder bone with tendons.

The bicep brachii contracts to lift the arm. I hope that this information was helpful in understanding what you need to know for the human and anatomy portion of the ATITs. If you have any additional questions, make sure that you leave them down below.

I love answering your questions. Head over to www.nursechung.com where there's additional resources on all topics and all things regarding the ATITs. And as always, I will see you in the next video.

Bye!

Transcript for:Overview of Human Anatomy and Physiology

Transcript for:
Overview of Human Anatomy and Physiology