welcome to introduction to anatomy and physiology chapter one the information in this video is credited to Elder Pearl Solomon the author of the book introduction to human anatomy and physiology anatomy and physiology Anatomy is the science of body structure physiology is the science of body function or how the Body Works anatomy and physiology are interrelated each body part is precisely adapted for carrying out its specific job anatomy and physiology are fields of science science is a way of thinking and a method for investigating the world in a systematic manner we observe the world around us and ask critical questions about what we see using the scientific method involving a series of steps we develop a tentative explanation and a hypothesis which we can test we test the hypothesis by performing an experiment we collect data from the experiment and Report the results in a conclusion about the hypothesis now let's learn about the levels of organization within the human body the simplest level of organization is the chemical level consisting of atoms and molecules atoms and molecules associate to form the organelles and cells of the cellular level cells associate to form tissues such as muscle or bone tissue and tissues may be organized to form organs such as the brain or heart some examples of organs are the stomach liver lungs brain or heart certain tissues and organs function together to make up an organ system or body system the body systems work together to make up the human organism the human organism is made up of 11 main organ systems that work together to maintain life they are integumentary skeletal muscular nervous endocrine cardiovascular lymphatic immune system respiratory digestive urinary and reproduction let's learn about the integumentary system its components are skin hair nails and sweat glands it has the following functions of one covers and protects body two helps regulate body temperature and three receives information about touch pressure temperature and pain the skeletal system has components bone cartilage ligaments joints its functions are help support and protect the body muscles attached to the bones the skeletal system works with a muscular system to carry out effective movement stores calcium stored bone marrow where the red white and other cells are produced muscular system components are skeletal muscle cardiac muscle smooth muscle its functions include skeletal muscle moves parts of skeleton Locomotion cardiac muscles pumps blood and smooth muscle moves materials in the body nervous system components are components brain spinal cord sense organs and nerves its functions are principal regulatory system receive stimuli from external and internal environment and transmits impulses to muscles and glands endocrine system components are pituitary gland adrenal gland thyroid gland and other ductless glands that produce hormones such as hypothalamus gonads pineal body parathyroid thymus its functions are works with nervous system in regulating metabolic activities and body chemistry and secretes hormones cardiovascular system components are heart blood vessels and blood its functions are transports nutrients gases hormones waste and other materials from one part of the body to another and helps maintain fluid balance lymphatic or immune system components are lymph lymphatic vessels lymph nodes spleen and other lymph structures its functions are collects and transports tissue fluid to blood absorbs lipids from digestive tract and transports them to cardiovascular system and defends body against viruses bacteria and fungi that cause disease respiratory system components are lungs trachea and other air passageways its functions exchanges gases between blood and external environment maintains appropriate oxygen content and helps regulate acid-base balance of blood digestive system components are mouth pharynx esophagus stomach intestine liver pancreas and salivary glands its functions are ingests and Digest foods and absorbs nutrients into blood urinary system components are kidneys bladder ureter and Associated ducts its functions are kidneys excrete metabolic wastes and helps regulate volume and composition of blood and other body fluids reproductive system components are gonads testes and males ovaries and females and Associated structures its functions are reproduction and maintain sexual characteristics those are brief descriptions of the 11 systems in the human body we will learn in detail in the subsequent chapters and videos try to remember the names of these systems now let's learn about how the human body is composed it's composed of ions inorganic compounds and organic compounds interact organic compounds are large complex compounds containing carbons such as carbohydrates lipids proteins and nucleic acid inorganic compounds are relatively small simple chemical compounds such as water salts and simple acids in bases look at the examples in the picture these are the chemical structures of organic and inorganic compounds you can see the complexity in the organic and the Simplicity of the inorganic compounds you don't need to learn the detail of these we will leave that to the biochemist body fluid contains electrolytes inorganic salts acids and bases that form charged particles called ions in solution positively charged ions are called cations and negatively charged ions are anions an acid is a compound that dissociates in solution to produce hydrogen ions h plus and some type of anion acid is a hydrogen ion plus an anion a base is a compound that dissociates in solution to produce hydroxide ions oh and some cations bases of a plus a cation the hydrogen ion concentration of a solution is expressed as its pH Ure water is a neutral solution with a pH of 7. blood has a pH of 7.4 please pause the video and take a look at the picture to roughly know where the household items fall on the pH scale when an acid and a base are mixed in water the h plus of the acid combines with the O of the base to produce a molecule of water the remainder of the acid and anion combines with the remainder of the base A cation to form a salt assault is a compound in which the hydrogen ion of an acid is replaced by some other cation below is the chemical formula of salt you don't need to know this formula organic compounds are large complex compounds that contain carbons a chemical compound is a molecule that consists of two or more different elements combined in a fixed proportion carbon dioxide consists of one atom of carbon and two oxygen CO2 the atoms of a chemical compound are held together by forces of attraction called chemical bonds as we mentioned earlier the organic compounds we will learn in this class are carbohydrates lipids proteins and nucleic acids carbohydrates are sugars and starches they are used as fuel and to store energy lipids include fats compounds that store energy phospholipids which are components of cell membranes and steroids which include several hormones proteins are complex compounds composed of amino acids some service enzymes and others function as structural components of cells proteins are abundant in meat fish eggs nuts beans legumes and seeds nucleic acids are large complex compounds two important nucleic acids are DNA which makes up the genes and RNA which is important in making proteins okay now let's learn about metabolism anabolism and catabolism metabolism the chemical activities that take place in the body for example converting the food we eat into energy catabolism the breaking down phase of metabolism provides the energy required for anabolism the building phase of metabolism and during anabolism energy is used to make chemical compounds and structures needed by the cell during catabolism glucose and certain other nutrients are broken down by cellular respiration their energy is captured and temporality stored in ATP adenosine triphosphate this energy is then used in anabolism the phase of metabolism in which molecules cells and tissues are manufactured energy is also needed for muscle contraction growth maintenance repair and many other activities cellular respiration is a catabolic process in which nutrients are broken down as the energy stored in these nutrients is released it is packaged within an energy storage compound called ATP adenosine triphosphate homeostasis and feedback mechanisms metabolic activities are carefully regulated to maintain homeostasis and appropriate internal environment or steady state homeostatic mechanisms are the self-regulating control systems that maintain homeostasis stressors stimuli that disrupt homeostasis cause stress that activates homeostatic mechanisms many homeostatic mechanisms are negative feedback systems in which the response of the regulator control center is opposite negative to the change negative feedback or balancing feedback occurs when some function of the output of a system process or mechanism is fed back in a manner that tends to reduce the fluctuations in the output whether caused by changes in the input or by other disturbances for example if the body temperature decreases the heating process is activated causing the body to shiver the Shivering causes the body temperature to increase to keep the body warm and brings it back to homeostasis and if the body temperature is high or hot the cooling process is activated causing the body to sweat sweating cools the body resulting in lowering the body temperature leading to homeostasis some homeostatic mechanisms are positive feedback systems in which variation from the steady state sets off a series of events that intensify the change positive feedback loops amplify their initiating stimuli in other words they move the system away from its starting state for example during labor the child pushes on the cervix stimulates and the body sends the signal to the brain the brain releases oxytocin to stimulate the uterus to contract as the baby pushes more oxytocin is released completing the positive feedback this continues until the baby is delivered a negative feedback in temperature regulation as we saw in the previous slide B is the positive feedback in Hemorrhage if we don't stop the bleeding the patient will die now let's change the topic let's learn about the anatomical position of the human body anatomical directional terms are applied to the body when it is in the anatomical position in this position the body is standing erect eyes looking forward arms at the sides and palms and Toes directed forward we will learn all these directional terms used in human anatomy Superior means above at a higher level inferior means below at a lower level for example the eyes are superior to the mouth the belly button is inferior to the chin this is another image of Superior and inferior you can think of superior is up an inferior is down anterior and ventral means toward the front or anterior surface of the body posterior and dorsal means toward the back or posterior surface of the body medial means toward the mid-sagittal plane lateral means away from the mid-sagittal plane proximal toward a reference point or Source within the body closer to the reference point distal away from a reference point or Source within the body think of distal as distant far superficial is near the body's surface deepest father into the body far from the body's surface for example arteries are deep and veins are superficial cranial encephalic means toward the head caudal means toward the feet rostral means toward the nose ipsilateral means on the same side you can see the shaded areas of the arm and leg are on the same side contralateral means on the opposite side you just learned all these terms you can try to memorize this table here is a quick summary of some of the directional terminology medial versus lateral superior versus inferior the interior is opposite to the posterior proximal is opposite to distal superficial versus steep ipsilateral versus contralateral there are three planes in human anatomy sagittal axial or transverse and frontal or coronal the sagittal plane is a vertical plane that passes through the body dividing it into left and right coronal plane is a vertical plane that passes through the body dividing it into interior ventral and posterior dorsal positions you can say it's dividing from front to back and vice versa see the orange color an axial or transverse plane is a horizontal plane that passes through the body dividing it into Superior and inferior portions regions and Cavities of the body the body may be divided into axial and appendicular regions the axial portion consists of the head neck and trunk the appendicular portion consists of the limbs the Torso or trunk consists of the thorax abdomen and pelvis terms such as abdominal pectoral and lumber are used to refer to specific body regions or structures now we have to learn the body cavities two main cavities dorsal and Central cavities dorsal cavity located posteriorly in the back and includes the cranial and spinal cavities ventral cavity largest cavity subdivided into thoracic and abdominal pelvic cavities the thoracic cavity further subdivided into two lateral pleural cavities purple color and a single centrally located cavity called mediastinum Orange the abdominal pelvic cavity is subdivided into the abdominal pink and pelvic cavities neon green abdominal quadrants and regions the abdomen area is divided into four quadrants and nine regions there are four anatomic quadrants right upper quadrant left upper quadrant right lower quadrant left lower quadrant the right upper quadrant consists of the right lobe of liver gallbladder right kidney portions of the stomach and small and large intestines the right lower quadrant consists of cecum appendix portions of small intestine right ureter right ovary and right spermatic cord the left upper quadrant consists of left lobe of liver stomach tail of the pancreas left kidney spleen and portions of large intestines the left lower quadrant consists of most of small intestine portions of large intestine left ureter left ovary and left spermatic cord the abdomen further divides into nine regions the superior portion of these nine regions has right hypochondrium epigastrium and left hypochondrium the middle portion has right lateral umbilical and left lateral the inferior portion has right inguinal hypogastrium and left inguinal okay we now have to learn the anatomic Regional terminology Regional terminology is used to reference anatomical structures or areas of the body similar to directional terminology Regional terminology is necessary for both being able to describe areas of interest and interpret prescriptions an example of using Regional terminology would be as follows a patient complains of headaches that only occur at the back of the head this can be communicated to the radiologist as occipital headaches there are quite a few terms we are going to learn one by one in the alphabetical order of this table here is the abdominal area see the red circle antebrachial means the forearm anticubital is the front of the elbow axillary means armpit brachial is the upper arm the calf is a lower posterior Porter of the leg carpal means wrist cephalic means head cervical means neck costume means ribs cubital means the posterior surface of the elbow of the arm phemeral means thigh area flank means the side of the trunk adjoining the lumber region most of the time the flank area is used to access and feel the kidneys gluteal is the buttock inguinal is growing Lumber is the lower back between the ribs and hips memory is the upper chest or breast occipital means the back of the head ophthalmic means I pectoral means upper chest or breast pelvic is the pelvis perineal means perineum plantar is the soul of the foot the popliteal is the back of the knee sacral means sacrum sternal is sternum thigh is the upper portion of the legs thoracic is the chest area umbilical is the navel vertebral means spine we are done with the anatomic Regional terminology this is the anterior view of the body with skin and most of the muscles removed the rib cage and the fatty membrane that hangs down from the stomach have also been removed the scrotum has been open to expose the testes and the penis has been cut transversely to show its inner just look at these and get acquainted with these structures you will not be tested to identify these structures in this chapter because we will learn the details in subsequent chapters this is the deeper interior view of the body the lungs have been cut to show internal structure and the hard and small intestine have been removed pause the video and look through the structures this is also the deeper interior view of the body the stomach small intestine and most of the large intestine have been removed the kidneys pancreas and other depth structures are visible once again pause and skim through the name of the structures this is a posterior view of the body muscles have been removed on the right side to show skeletal structures and the position of the kidney pause the video and run through the name of the structures this image is a series of computed tomography CT scans through various regions of the body the level of the scan is indicated on the figure of the body the color spectrum bar indicates the gradient of the structure density is represented by color the more dense structures such as bone appear white in the scans the least dense structures appear red thank you for watching please subscribe comment like and share