Skip to main content
Loading Explore guides…
Human Physiology · Acedra
Home
Explore
Biology
Human Physiology
Sign in to save
Chat
If YouTube asks you to sign in, open the video on YouTube.
Watch on YouTube
Reload player
Transcript
51 segments
Copy
Hide video
0:00
[Music] hello and welcome to intro 101 my name is Kris and I am your neuroscience and psychology graduate student assistant I'm here to assist you with related science Basics you interact with on a daily basis so you can start or continue to build a foundation in human biology and and Physiology that can better help you engage with the information you consume from your favorite health and wellness Educators and influencers much like the way a graduate assistant helps
0:41
prepare intro students so they can better engage with lectures delivered by their professors or maybe you just like a better idea of why your body functions the way it does either way stick with me for the next few minutes and I'll do my best to explain what's going on in there today's episode is intro to physiology 101 we'll take a contextual sweep through human physiology so we can begin to
1:06
build the foundation of what's to follow in this series I'll suggest some hopefully solid reasons why everyone should understand the basics of physiology in terms of how and why our bodies function the way that they do I'll also give you a brief anatomical overview of micro to macro processes involved in physiology and introduce you to a few physiologists whose work I found relevant to health and wellness and hope that you will too before we start I'd like to respectfully
1:34
acknowledge with much gratitude that intro 101 is recorded on the unseated and ancestral territories of the Kwantlen, Katzi, Matsqui, and Semiahmoo First Nations additionally we here at intro 101 believe wholeheartedly that science is for everybody in fact the richness complexity and strength of scientific research is astronomically improved by the inclusion of many varied voices in an effort to help everybody have access to education research resources and representation
2:06
across scientific Fields the world over I will be sharing a few organizations in the show notes that are working very hard to promote and Grant access to stem Education and Research resources around the world please check them out and if you are able please support them in any way that you can you can donate you can share their work on your social media networks or maybe volunteer your time
2:29
to help them if you already generate opportunities that provide access to stem education and resources within your own communities or support stem education organizations not listed here please share them in the comments below if you'd like others to contribute as they are able all right welcome to class let's crack on with intro to physiology 101 so what is physiology and why do we need to understand it well the basic premise of physiology is understanding why and how the
3:02
body works mechanistically from the efforts of teeny tiny atoms to the integration of whole body systems why is it important to know this well so much of the science we interact with on a daily basis involves our body moving it thinking about moving it even thinking about thinking these all require physiological processes understanding the basics of our body's physiology can help us to better engage with the world around us it can also help us better understand the multitude
3:38
of health and wellness protocols that fill our inboxes and social media feeds health and wellness protocols can be anything from moving our body to nutrition plans to mindfulness practices to the smooth working of our inner Plumbing they often sound amazing and sometimes our lives are changed because of them but also sometimes from one influencer to another you might find some contradictions between protocols that are meant to have similar outcomes or they get complicated
4:11
or time consuming and some of them may not generalize to all populations and how do we know if they do it's a lot to wrap our minds around and sometimes it can get overwhelming understanding how the body functions empowers us it helps us parse the information we consume into what may or may not benefit us and why we may even discover that a protocol that seems Out Of Reach to us can be modified for wherever our bodies are at physiologically and for those who are
4:45
already comfortable with any and every protocol you engage with first of all congratulations well done and second understanding body and brain physiology may help you better maximize those protocol benefits for some of you this information is going to be a primer and for others it will be a refresher you'll likely be familiar with some of the terms that pop up but my hope is that the more
5:10
you understand these terms and the more context we can put to these terms the faster you will be able to access their meaning and their functions within the body when you are reading or listening to your favorite health and wellness influencers okay so the basis of physiology is not just how the body functions but why it does the things that it does the main why is homeostasis you have likely heard
5:37
this term at some point in your lifetime so what is it homeostasis is a state of balance our bodies all of its systems all of its parts right down to those teeny tiny atoms have a role in maintaining balance inside of our bodies why is this important because when our bodies are in the state of equilibrium we function well we can survive in our environment when it's thrown off due to some
6:09
external stimulus or internal malfunction the body engages all parts and systems necessary to bring it back into balance if it can't come back into balance if it stays out of balance we can become vulnerable to varying degrees of dysregulation and that can lead to diseases and disorders which is why we sometimes seek out protocols in the first place we're out of sync we're out of balance and
6:38
it's impacting our ability to function in our daily lives an example of a homeostatic response to an external stimulus is the stress response and we'll get incrementally deeper into the mechanics of this response in subsequent episodes but for now the stress response is a beautiful and necessary physiological response to something that may or may not threaten our survival what evokes the stress response in us is going to be relatively different for each of us but here's a
7:11
popular example found in many textbooks imagine you're walking down a nature trail and out of the corner of your eye you spot what might be a very dangerous snake and in that moment so many things kick off inside your body so ridiculously fast it's bananas the gist is that your Visual and or auditory systems tell your stress system to engage so it secretes hormones that attenuate one subdivision of your nervous system and fire up a whole other nervous system that increases your
7:44
heart rate and dumps energy into your muscles so you're ready to either attack the snake or run away from the snake or stand so still you become one with the trees and maybe the snake won't sense you but it will because snakes are heat seeking predators or if you're like me you may just pass out and your fate is left to the mercy of timing and the snake's last meal let's hope it's not hungry here's the kicker if you don't pass out your wonderfully evolved human
8:14
evaluative system at the front of your brain will take a moment to kick in and realize "Ah that's not a snake! That's just a fallen branch. Sweet relief!" The stress system settles, there's a switch back to normal programming and you're back on your way. so quick recap the body's stress response to the external stimulus, the snake, is its attempt to keep you alive. it's your body coordinating multiple systems to maintain homeostasis when confronted by a stressor. it's a
8:47
homeostatic protective response and it will keep kicking in until you perceive your body is safe and can get back to business as usual. homeostasis is a dynamic and constant process of bringing some measure of balance to your body. I'll try to bring each episode back to the relevance of homeostasis firstly because the goal of so many of the protocols we try are ways to either mitigate or
9:12
optimize stimuli in order to maintain or advance internal processes that lead to homeostasis and secondly because nearly everything we interact with requires some kind of physiological response that is trying to keep our bodies in balance so how do we maintain homeostasis how does it work for the body to maintain homeostasis it recruits loads of internal parts each with its own job to Monitor and regulate an ideal functional level called a set point a set point is a range of
9:47
values within which the body optimally functions for instance a normal body temperature Falls within a small range on either side of 37°C or 98.6°F the body monitors this range or set point by way of something called a negative feedback loop a negative feedback loop is the constant participation of body parts that act as sensors, control centers or affectors it works like this tiny receptors throughout your body function as sensors that monitor set points in the example of
10:27
internal body temperature temp the set point as I mentioned is 37°C or 98.6°F and the receptors continuously monitoring that value are called thermoreceptors if your temperature deviates too far from its scent Point those thermoreceptors alert a control center in this case it's the hypothalamus and that lives in your forebrain the hypothalamus will activate an affector to help return turn the temperature to its set point of 37° C for example if your temperature drops
11:06
too low the hypothalamus will send signals to skeletal muscles to make you shiver and release heat if it elevates too high it will send signals to sweat glands to secrete sweat to cool you down until your temperature returns to its set point that's just one of a bazillion homeostatic negative feedback loops going on in your body at all times there are a number of receptors control centers and affectors in the body and they involve numerous parts we'll get to know many of these
11:42
parts incrementally over this series but a quick overview looks like this the body is an incredibly dynamic organized and efficient organism from the smallest hardworking components to rigorous interdependent systems our bodies are composed of atoms molecules cells tissue organs and organs are organized into multi-part systems so starting with atoms atoms are the smallest building blocks
12:15
in our body and the most common include carbon hydrogen oxygen and nitrogen we are carbon-based life forms you may have even heard it said that we are all made of star stuff that was the late astrophysicist Carl Sagan and he's referring to those particular elements oxygen hydrogen carbon and nitrogen are all born in the nuclear cores of stars but how those elements made their way from Star guts to bases of all life on earth is a bit of a mystery there are theories but I'll let
12:51
you look those up but it is quite fascinating regardless all life on earth has a combination of these and other atoms doing their business at microscopic levels so yeah the tiniest building blocks found in our bodies are also found in stars and they can exist in atomic form or in ion form and what makes them ionic is that they are electrically charged some ions that play important roles in homeostasis in our bodies are sodium potassium chloride and calcium and their
13:26
functions will become more apparent when we get deep into nervous system cell physiology at the next level are molecules so when two or more atoms bind together they form molecules so even some of the atoms mentioned Like Oxygen are found naturally as molecules though they also exist as a singular atom in humans there are thousands of molecules and they all have a critical function the most abundant molecule in the human body is is water H2O two hydrogen atoms and one oxygen atom
14:04
bound together others you'll recognize are in forms of proteins fat genetic matter and carbohydrates a really important molecule that probably comes up a lot in health and wellness discussions is adenosine triphosphate or ATP or adenosine triphosphate adenosine adenosine something like that I'm just going to call it ATP because that's what everyone else calls it ATP in a nutshell is the form of energy that's usable by your cell to carry out their functions you've
14:40
also probably heard of neurotransmitters and neuromodulators and those are also molecules so molecules are chemicals necessary to sustain life and they are packaged within tiny fatty membranes called cells within the cell they make up tiny structures called organ El and each organelle has a very specific function you've probably heard of mitochondria mitochondria is just one of many organelle and it is sometimes referred to as the cell's powerhouse because it has a very
15:12
important role in the synthesis of ATP again ATP is adenosine triphosphate and it provides the fuel needed for cells to do their business cells are ridiculously cool little entities they are their own self-contained living thriving units that provide structure and function to living things and carry out life sustaining processes again at microscopic levels they work hard at keeping you alive and we'll dive deep into the cell's own little Universe in an upcoming episode so
15:48
stay tuned but for now it's important to note that cells are the smallest living bases of operations in our bodies and there are many different kinds that carry out very specific functions examples of cell types that might be familiar to you are neurons skin cells blood cells fat cells and loads more now clumps of cells together form different types of tissue and tissue has important functions
16:18
depending on how those cells are arranged like cell communication fluid secretion muscle strength and movement and some times tissue acts as a protective barrier we have four types of primary cell tissue first there's nervous tissue some of the cells in our nervous tissue initiate something called an action potential which is like an electrical pulse and these pulses are transmitted to other nervous tissue in our body when you hear phrasing like this brain part sends
16:52
a signal to some other brain or body part these are those signals electrical pulses firing around our nervous system making things happen this is an example of cell to cell communication remember I mentioned those electrically charged ions sodium calcium potassium and chloride they play a significant role in nervous tissue cell to cell communication stay tuned for that in an upcoming episode Another primary tissue is epithelial tissue our skin is made up of
17:26
loads of epithelial cells and those can act as a protective barrier to the rest of your body but interestingly you'll also find epithelial cells in the digestive tract and those act as nutrient absorbers so though epithelial tissue can act as a barrier to the body in one organ in another it intentionally allows some things past the gate ideally just the beneficial things our glands are
17:53
also composed of epithelial cells and they secrete all kinds of hormones that kick off many processes in the body and of course your skin secretes sweat along with protection absorption and secretion epithelial cells can also act as diffusers filters and they also work with nervous tissue to detect sensory information another primary tissue is muscle tissue we have skeletal muscle tissue
18:19
and that tissue involves strength and moving the body around we have cardiac muscle tissue and that moves blood out of the heart and we have smooth muscle tissue some of which you'll find in your digestive tract and lastly we have primary tissue that is connective tissue this is supportive tissue like ligaments tendons and those assist with movement and flexibility from tissue we move
18:45
to organs at least two different tissue types make up an organ and organs have loads of functions in the body for example your gastrointestinal tract not only has epithelial tissue tissue and smooth muscle tissue but it also has nervous system tissue all of which are necessary for digestive functions there are many organs in the body too many to list here but some other examples of organs we will visit throughout this series are the brain heart skin lungs liver pancreas kidneys
19:19
loads of glands think pituitary adrenal thyroid etc even your nose and eyes are organs now groups of organs make up body systems there are 11 body systems and they all work together to keep you functioning there's the integumentary system which is mostly your skin and glands there's skeletal muscular circulatory respiratory digestive reproductive urinary endocrine and immune systems and lastly the one system we will spend the next many episodes deconstructing is the nervous system
19:59
the nervous system impacts all of these other systems and all of these other systems can impact the nervous system the nervous system has two main parts the central nervous system which is your brain and spinal cord and the peripheral nervous system which is branches of nerves extending from the brain and spinal cord to all parts of the body the nervous system will be our home base but you will come to see how incredibly dynamic all of these systems are none work in
20:29
isolation of the others the body is a magnificent machine and the nervous system is one key to its regulatory function regardless of where you are on the spectrum of physical and cognitive ability and it is most often referenced in mental and physical health and wellness protocols so let's recap physiology is the why and how our bodies function homeostasis is the why that is our body's constant striving for balance the how is the body recruiting multiple internal parts and systems
21:06
and it's their mechanistic function that achieves homeostasis through negative feedback loops from micro to macro these parts and systems include atoms that beget molecules that are packaged inside cells cells carry out life sustaining processes and clumps of cells form tissues two or more tissues make up organs and multiple organs make up interdependent systems that work hard to keep you alive one of those systems is the nervous system and it has a regulatory function that can
21:40
impact all of the other systems and it's our home base for this series now important caveat there are times when we purposely disrupt homeostasis in an effort to challenge the body to respond and return to balance during rigorous demands on his resources this is known as exercise and because it requires prolonged coordination of nearly all of our body systems but in ways in which we have psychological control the body responds rather differently than it does to a stimulus like
22:15
that maybe snake on the trail it makes us feel pretty good and it enhances the function of most of our body systems we'll revisit this in a later episode after we've had a really good look at the nervous system and all of its parts and we'll try to make sense of why purposely temporarily stressing the body can be good for homeostasis but unexpected and or unwanted prolonged stress can be
22:43
troublesome for homeostasis so that's it for this episode I know it's a lot to digest but hopefully that gives you some context from which we can get deeper into the physiological mechanisms that keep our bodies in balance your homework for this week should you wish to further explore physiology is to have a look at the wonderful work and research of many different physiologists physiology is a vast and fascinating subject but to get you started here are a few physiologists whose
23:16
work I found really interesting and relevant to health and wellness their research is quite Advanced but looking at their bios and their research interests will give you an indication of how important understanding human physiology is to an enormous array of health and wellness interests if you are interested in Reading their research but don't have much experience reading quantitative research I suggest reading the abstract the introduction and the discussion
23:45
sections of their papers to get an idea of the purpose and results of the studies if they have a limitation section that is also a worthy read as that will highlight any possible discrepancies in the study that they couldn't control for and should be considered in any interpretation of the data okay so one physiologist whose research I've recently come across is Dr Sandra Agyapong-Badu she is a research fellow at the University of Birmingham in the UK and much of her research
24:16
involves the physiology of skeletal musculature for active and healthy aging and how to reduce sedentary behavior in aging populations I'll post links in the show notes but you can also use Google Scholar to search for hers and other physiologists research another brilliant physiologist is Dr Priscilla Day-Walsh at The Quadrum Institute also in the UK some of her re research looks at how the gut microbiome affects physiological functions in the heart liver and
24:47
brain another masterful physiologist is Dr Sarah England at Washington State University Medical School her lab has recently conducted did really interesting research on how pregnancy outcomes can be affected by disrupted circadian rhythms and lastly the work of multi-award recipient and Brilliant physiologist Dr Nancy Carrasco is worth your time her vast repertoire of research involves transporting particular molecules across cell membranes in the thyroid which has informed
25:22
thyroid cancer treatment and potentially breast cancer treatment if you do get a chance to look at their research or the research of other physiologists let us know in the comments what you found interesting or helpful in growing your understanding of physiology also either at the end of the show notes or pinned in the comment section you'll find a list of papers and books I sourced to write this episode so you may find something of interest there as well okay
25:48
lovelies thank you for being here again please check out the stem organizations in the show notes and support them or others in any way that you are able I have no relationship with these organizations I'm just a fan of the work that they're doing and I hope that you will be too if you liked this episode please click the like subscribe and the notification Bell if you haven't already and please share it with your friends and neighbors and family and anyone you think
26:15
would benefit from understanding their body a little better until next time take care out there [Music]
26:38
there's the inte integumentary system integumentary system integument integumentary integumentary integumentary system intake ENT I don't know if I'm saying it I've said it too many times it doesn't sound like a word anymore integumentary that can't be right that doesn't sound right anymore integumentary just going to go with it
Here to help you learn
Sign in to keep a private conversation with your course tutor.
Ask me anything about the material…
Sign in to chat