Integumentary System: Anatomy and Physiology I Lab

Integumentary System: Anatomy and Physiology I Lab



welcome to the anatomy and physiology 1 series on the skin or the integumentary system remember that the integumentary system includes the cutaneous membrane or the skin as well as all of the accessory structures that are associated with the skin for example the hair the nails the glands that release oil and sweat onto the skin's surface today we're going to quickly go through this model of the integumentary system the cutaneous membrane itself where the skin itself is divided into two major regions the epidermis and the dermis the dermis is this region that you see right here hmm above all of this yellow fat or adipose tissue all the way up to this curvy line that you see here so this again is the dermis the major layer of the skin or cutaneous membrane above the dermis we have the epidermis at these above so epidermis above the dermis again from this curvy line distinct curvy line that we see all the way up to the surface of the skin the exposed surface of the skin is the epidermis we see that the epidermis is different in the two types of skin that we have we have thick skin on the palms of our hands and soles of our feet which is a tougher thicker skin because our feet and hands are stressed a lot more than the rest of our skin and you can see that by looking at and it's tougher it's thicker it has calluses on it so when we look at the model and we're trying to determine if it's thick skin or thin skin we can look for two different features one in thick skin we have a thick top layer or stratum corneum stratum just means layer okay we have a thick stratum corneum as opposed to a thin stratum corneum and thin skin also in thick skin we have an extra layer in the epidermis you see this yellow line here this yellow line is showing you the stratum lucidum okay when we look at thin skin there is no yellow line there is no stratum lucidum okay so thick skin has an extra layer in the epidermis it actually has five layers in the epidermis and it has a thick stratum corneum or top layer speaking of the layers and epidermis the epidermis is broken up into either four or five layers of cells these cells are called keratinocytes okay because their cells that get keratinized or packed with keratin when we look at the layers in the epidermis will start at the very bottom layer and we'll say that that layer is called the stratum basale hey it's on the base or bottom of the epidermis what's easy to remember they filled with basal cells that continuously divide so this single dark layer on the bottom here is the stratum basale next up we have a layer called the stratum spinosum then we see that the model get a little bit lighter as we go up in this area right here is almost more gray or white is the stratum granulosa okay so all skin thin skin and thick skin have those layers this drawing base out the stratum spinosum the stratum granulosa okay next in thick skin we have the stratum lucidum again we do not have that in thin skin and then the final most superficial layer the layer on the top of the skin is the stratum corneum okay and that's a sticky area here or this thin area here in thin skin okay so those are the layers of the epidermis we said that the epidermis and dermis have this curved line between them okay the reason for this curved line is to increase the surface area between the two layers so that they can be bound together more tightly when we look at this curved line we see that there are parts of the epidermis that extend down into the dermis each of these little projections each of these little fingers that reach down is an epidermal Ridge so epidermal Ridge epidermal Ridge epidermal Ridge the parts of the dermis that reach up into the epidermis are called dermal papilla okay and that's with an a e on the end and that's going to be very important because we see that there's another structure that spelled the exact same way without the e on the end so going down to the dermis we have our dermal papilla that stick up and this dermis is split into two regions two layers the thin top region of the dermis from about here up okay so this small little area is the papillary layer or papillary region it's the part that has these dermal papilla any sort of journal papilla are in the papillary region though bigger deeper part of the dermis is the reticular layer or reticular region when we look beneath the cutaneous membrane we have the cutaneous membrane or skin with the epidermis and the dermis beneath this cutaneous membrane we have this area right here we call this area the hypodermis hypo means below so the below the dermis hypodermis we also call this area the subcutaneous layer because remember this is the cutaneous membrane so beneath the cutaneous membrane is subcutaneous South is below just like the subway goes below the ground when we look at this hypodermis or subcutaneous layer we see that we've got lots of these yellow globules this is showing us adipose tissue or fat tissue that's where all of the fat and lipids are stored beneath your skin when we look at this region we also see that we've got big blood vessels coming in and you'll notice that's what we see in blue and red you'll notice that we also see these blood vessels up here scattered throughout the dermis but they end they sit up at the top of the dermis these blood vessels do not enter the epidermis because the epidermis is a vascular it does not have a direct blood supply so that's the that's the the overall explanation or overall gist of the cutaneous membrane and its basic layers the epidermis the dermis and hypodermis when we look at the cutaneous membrane and we see all of these associated structures pay all of these accessory structures that are associated with the skin when we look at all of these accessory structures we see that they start down deep in the skin they start either in the dermis or hypodermis and then they often extend up through the epidermis the reason that the structures start down in the dermis is because we have a supply here these are living functioning working cells so they need oxygen and glucose to be brought to them they need their waste products to be carried away so that's why we have them down here in the dermis where we have plenty of blood supply so looking at the accessory structures we'll start with the hair each one of these Brown structures is showing you a hair again you see that it starts down deep in the dermis and extends up and out past the epidermis which is why you can see your hair on the outside of your body when we look at the hair we can break it up into a couple main portions or parts the root of the hair is the part that's below the surface just like the roots of a tree are beneath the ground this part that extends out past the epidermis is the shaft so the shaft and the root when we look at the base of each hair we see this swollen area here that part where it gets a little bit wider that's the bulb the hair bulb just like a bulb a tulip bulb looks just like this when we look at the very base of the hair here you see this little notch or this little opening where we have blood vessels feeding into the hair that is the papilla with an A on the end hey it's a dermal papilla or a hair papilla with just an AM and that's where we have the hair matrix with all of these living dividing cells that allow the hair to be pushed up and to grow that's what we have a blood supply there because they're living cells once we extend up this way the hair becomes just dead cells with lots of keratin in them and that's why it doesn't hurt when you cut your hair or style your hair because it's not actually living anymore it's just this part down here it's allowing the hair to grow that's living so we have the papilla at the bottom may this swollen area of the bulb the part underneath the surface is the root and the part that sticks out is the shaft you see surrounding the outside of the hair we have a hair follicle and the follicle is actually made up of epidermal cells you see that the same color has these epidermal cells because during development these epidermal cells actually extend down into the dermis to form this hair follicle also associated with the hair we see then we have this this red structure over here and this is the muscle this is called the erector pili muscle and when this erector pili muscle contracts it makes your hair stand up on end you'll notice that happens when you're very cold and also when you're scared here people say you know when they were really scared the hair on the back of my neck stood up well that's true that really happens and also when you're holding you get goose bumps your hair stands up and that's a leftover evolutionary trait because in animals that have hair all over their body when they're cold and their hair stands up on end their hair is a better insulator it's a better coat to keep them warm also when they're scared and the hair that's all over their body stands up on end they look bigger and scarier so that they're less likely to be attacked so that's why we have this erector pili muscle that makes our hair stand up also associated with the hairs you see these blue structures here these new structures here are glands they're exocrine glands it makes secretions or fluids that we Supreme onto the body these glands associated with the hairs here have been doing Lance called sebaceous glands and sebaceous glands make something called sebum which is oil so you see that they're associated with the hair these sebaceous glands produce oil and release it onto the hair and that's why if you don't want your hair for a few days it gets oily this um the purpose of this oil is to one lubricate but also it's got antibacterial properties to help prevent bacterial infections from occurring in here we also have a couple other types of glands we have two different types of sweat glands these smaller white glands with these long ducts they come up to the surface of the skin are showing you acronym sweat glands eccrine and these are the typical sweat glands that you think of when you get sweaty you have this salty sweat all over your body to try and cool your body down these are the glands that are making that sweat these eccrine glands this here is showing us a different type of sweat gland this is an AVO print sweat gland and Apryl print glands produce a type of sweat video it's a little bit smellier to sweat and it's got pheromones in it so these are located only in areas that have hair that starts to develop at puberty so the underarms the groin so these lands they don't pull us down okay these a bow print sweat lamps have to do with attracting the opposite sex and they only become active at puberty because before puberty we don't need that to occur so you can tell the difference between oil glands or sebaceous glands and sweat glands because the sweat glands have a much longer duct they release their secretions through a long duct these eccrine sweat glands pull us down release straight onto the surface of the skin through a sweat core so this little hole here are these ones shown on the top are showing you pores now this a book print sweat gland can release directly under the surface like this or this long duct can go to a hair paste or don't be confused if you see this gland with a duct that goes towards a hair you can tell the difference between a book group plans and the sebaceous gland because this a book complaint will have a longer duct even if it's going to a hair it will have a longer duct whereas you see these sebaceous oil glands are really really just they're really closely associated with the hair itself so the last thing that we'll talk about are the touch receptors that we have down here in the dermis and when you use your hands to touch things you get all sorts of different sensations you can sense pressure you can sense pain temperature you can sense texture you can grasp on that sense how how hard you're grasping something your hands have lots of receptors in them your skin in general has lots of receptors in it these are nervous system type type structures that send a message to our brain that tells us what it is that we're feeling the two different types of receptors that we'll look at right now are called tactile corpuscles and laminated pacinian corpuscles these tiny little white rods that you see up at the very top of the dermis these are called tactile corpuscles those give us information about light touch deeper down here we see these bigger structures that are caused laminated or lamellar corpuscles they're also called pacinian corpuscle these are the ones that actually look like an onion you see all of these rings in it they look like an onion and you'll notice that both of these the tactile corpuscles and the pacinian corpuscles have this little attachment here these little attachments are going to neurons that are located deeper in the body so that when this is compressed we know that we're touching something we're pushing on something and this tactile corpuscle will fire a signal down to the neuron which will send a signal up the spinal cord into the brain so that we know that we're touching something so that summarizes what you guys are going to need to know for the integumentary system thank you and next we'll do the skeletal system

21 thoughts on “Integumentary System: Anatomy and Physiology I Lab”

  1. This video was extremely helpful! I now have a clear understanding!! I watch this 3 times day and now, I can name it all in my sleep. Thank you sooo much for creating and posting this video πŸ™‚

  2. This video is such a relief to me .i understand it better thanks for using this pic to explain the glands and layers of the skin πŸ™πŸ™πŸ™

  3. So glad I found your channel!!! Such clear and straight to the point content, kinda wish you were my instructor lol

  4. Omg i didnt want to video to stop! Thank you so much for this great video😍 I have a test tomorow and this was so helpfulπŸ‘πŸ»πŸ‘πŸ»πŸ‘πŸ»πŸ‘πŸ»πŸ‘πŸ»

  5. Thank you for posting this. I will be looking to see if you have a video on Microscopic bone. Thank you again.

  6. About to take my test and I'm feeling much more relieved. You explained everything really good, you're a great teacher :). Don't stop making videos please, they help us out a lot

  7. So clear and to the point.. best video I've seen on the anatomy of the integumentary system.. I wish you were my teacher!! I can tell you're an amazing teacher.

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