hey guys welcome to my second video on physiology and today's topic is homeostasis how the body is balanced so let's get started homeostasis what does that even mean so homeo means similar stasis stable or standstill so homeostasis is how to keep the body's internal environment constant this is different from hemostasis because hema means blood hemostasis is how to control your blood talking about bleeding coagulation and stuff like that that's why we have the field of hematology which is the study of blood so homeostasis is different from hemostasis when you first start learning about anything what's the first question what's the definition so what is homeostasis it's the maintenance of nearly constant circumstances in your body's internal environment the internal environment of your body is usually the e CF extracellular fluid as of TOD before in the previous video as an example here you have the hydrogen ion concentration usually they should be less than 5 nano moles per liter this is zero point zero zero zero zero zero zero zero zero five moles per liter very tiny amount but it's tightly regulated in fact only in our range of pH is compatible with life usually the pH is between seven point 35 and 7.45 theoretically you can live between seven and seven point seven pH anything less than that or more than that you're dead these numbers are not actual numbers the pH is a logarithm so they are very teeny tiny amounts of hydrogen any excess any decrease and you're done so I see homeostasis is very serious but what's the definition of disease disease is nothing but it is ruptured homeostasis Wow so diseases called pathology homeostasis is called physiology and new field of science is born pathophysiology so how does your body work you have the good stuff such as nutrients the bad stuff the waste products and carbon dioxide and you need communication systems so how to get the good stuff to get nutrients you need to eat this is the gastro intestinal tract to breathe you need the respiratory system to get oxygen okay now how to give the food and oxygen to every single cell in your body you need the circulatory system or cardiovascular system also known as CBS not the pharmacy okay then we have the bad stuff the waste products the liver and the kidney we'll deal with this junk for communication fast communication you have the neurons very fast for slow communication he will need stuff called hormones so let's talk briefly about every system in your body we start with the circulatory system or cardiovascular system heart pumping blood into arteries they go into capillaries or capillary bed exchange will occur with the cells blood will give the cells nutrients and oxygen and will take the waste products and co2 plasma which is in the blood is continually mixed with the interstitial fluid between the cells very important now let's go to the lungs now we have all the co2 and waste products going back to the heart the heart will pump them in a pulmonary artery open the co2 to the lungs the lungs will breathe out the co2 called exhalation and will breathe in the oxygen called inhalation now oxygen can go to the blood and the cycle goes over again co2 is the most abundant of all metabolic products let's talk about the GI and the liver you eat from your mouth of course and then it goes to the stomach then the small intestines not all of the absorbed stuff is cool no we need some lab to tell us is it useful to us now should we wait and store it should we converted to other more usable stuff and this is called the liver your body's laboratory your body's laboratory will change chemical compound it will store products and will eliminate waste products very cool and now the kidney the kidney is king filters the plasma some of which will be reabsorbed other will be excreted in urine good bye acid-base regulation to regulate the pH of your blood also some endocrine function to the tech savy here let's talk about communication you have the very fast nervous system composed of neurons or nerve cells starts usually in the skin to pick stimuli so this is the skin and this neuron here is called the sensory neuron let's say that you're touching a hot object okay very hot so it will tell your CNS or central nervous system which is the brain and the spinal cord that there is something hot here it will relay it through an inter neuron to another one which is now a motor neuron to tell your muscles pull up your hands from this hot object you idiot second the slow system the hormonal system we have some glands called endocrine glands such as this nice thyroid gland and able to create thyroid hormone directly into the bloodstream thyroid hormone is carried by the blood and now thyroid hormone is like the oven of your body everything is hot everything is working so fast that's why patients with high her thyroid ism they have they feel hot all the time all of their systems are working very fast they lose a lot of weight etc on the other hand patients with low thyroid level also known as hypothyroidism they gain weight they feel cold it's the opposite so hormones are very very important before I let you go here is a question for you the extracellular fluid has blank sodium ions then it's intracellular counterpart so does the extracellular fluid has more sodium less sodium the same sodium as the intracellular or is it variable if you'd like to know the answer go to my Facebook page facebook.com forward slash medic OSIS and let me know what you think the answer is down below in the comments I'll see you in the next video with a new physiology video but now don't forget to subscribe and hit the bell also like to see on Facebook Twitter SoundCloud Instagram and please consider supporting this channel on patreon thank you so much for watching this is medical is perfection Alice as always be safe stay happy and study hard