hey everyone it's sarah with registered nurse Orion comm and today we're going to go over a teaching series for anatomy and physiology specifically the integumentary system also known as the skin system in this video I'm going to go over some things you may see on your anatomy and physiology exam I'm going to cover the function of the skin layers I'm going to go over the function of the appendages of the skin and the sensory organs then afterwards we're going to take a little short quiz and I highly encourage you to visit my website registered nurse RN calm and take the other part of the quiz that goes along with this video because chances are you'll see some of those questions on your exam coming up and I want you to be as prepared as possible for the exam so let's get started first let's talk a little bit about the skin the skin and its appendages make up what's called the integumentary system the skin is an organ it's not a tissue that performs a bottl function for our body some of the functions it performs are controls our body temperature protects us from UV radiation and from the Sun and other environmental hazards also we have sensors in our skin that help protect us by making us more aware of our environment for instance say that we're fixing to touch something hot our sensors in her skin since that and allow us to pull our hand back before we become really badly burned so our skin is an awesome organ now let's talk about the two distinct layers of the skin you have two distinct layers you have first the top layer which is the epidermis then you have the second layer which is the dermis but the epidermis is the superficial layer so it's the one on the top the next is a dermis life layer which is a fibrous connective tissue that is just below the epidermis now you have a layer below the epidermis that's called the hypodermis the hypodermis is not part of the integumentary system but it's included in any diagram you may see or you look at it's just a little fatty layer underneath the dermis that helps keep our body warm but that's really important to remember at the hypodermis is there it's a fatty layer but it's not part of integumentary system now let's go over this diagram behind me of all the appendages and sensory organs and I'm going to go to the function of each so if you want take some notes here is a basic drawing of a skin layer and we're going to go over these each individually first let's go over the layers of the skin we have the epidermis which is the superficial layer it is made up of keratinized stratified squamous epithelium that contains four distinct types of cells and I would make note of this you have the first type is care to know sites you have melanocytes Merkel cells and Langerhans cells that make up the epidermis next we have the dermis this is the second layer below the epidermis and it is a strong connective flexible tissue it contains nerves and nerve fibers and blood vessels which you can see the artery and the vein right there and in the dermis we have two layers we have the dermal papilla and this is the superficial layer it only makes up 20% of the dermis so remember that it only makes up 20% and it has finger-like pegs right here in this drawing I flipped it up so you can see because it connects to that and there like finger like pegs which rests on your epidermis and then next right here you have the reticular layer and this makes up 80% of the dermis and it is just a network of collagen layers next we have the hypodermis and like I said it's not technically part of the integumentary system but it is listed whenever you're studying it and it's just a fat layer and what it does is it acts as an insulator for our body to keep us warm now on to the appendages of the skin there are Pinta jizz and they are called you have the hair follicles you have the sebaceous glands sweat glands and of course nails with the nails are not shown in here so those are the four different types of appendages of the skin now let's go over the hair which is like a hair shaft the hair function is to allow the body to sense things like lightly touch our skin and areas of our body to keep warm for example eyelashes why do we have eyelashes to keep our eyes from having particles in it and even our nose hairs keeps us from inhaling lint so your hairs play a great function for your body and the next you have the hair follicle this is this little green layer outlining this hair shaft and the hair follicle just extends from the epidermis into the dermis and the next you have the root plexus this is a nerve it's a knot of sensory nerve endings that wrap around the hair bulb and what it does is like whenever your hair gets touched or barely moved you can fill it and the reason you can feel when your hair is moved or touched is because of the root hair plexus it's a sensory nerve that allows you to feel when someone touches your hair next we have the erector pili eye muscle this little muscle is located where your hair shaft is around that root hair plexus and what it does is it is a bundle of smooth muscle cells that produces goosebumps on the skin so the key to remember with this erector pili eye muscle is it produces goosebumps that's probably going to be a test question think how you remember that is a rector it erect your your skin your hair so whenever you get goose mom's you your Skinner Rex and the hairs on your arm stand up so just remember that for erector pili I'm muscle next around the Richter pili I muscle are sebaceous glands these little green things right here and sebaceous glands are known as oil glands they produce an oily product called sebum and it's there found everywhere these little glands are found everywhere except for the palms and soles of your body so remember that no suspicious sebaceous glands on the palms or the soles next we're going to go to what's called the sweat glands and these are also called Souter if risk glands a and they produce sweat and notice we have a pore right here and right here and this little purple thing going down is a sweat gland because you sweat out of your pores and sweat glands or sudoriferous glands are found everywhere except on the nipples or parts of the external genitalia so that's the only place you won't find those now there's two types of sweat glands and here in this picture we just have one type but I'll go over the second type here in a second but we have what's called an indirect endocrine gland and this is a duct of glands that runs to the opening of the skin called the pore and it's secrete sweat and there are numerous endocrine glands on the body now you have the second type which is the apocrine gland this is not on the diagram like I said because of where they're found they're found in the axillary anal and genitalia areas and they produce like a special type of sweat that contains fatty substances and proteins and they're not as numerous as your endocrine glands but it's always good to know that there's two net next we have the Meissner corpuscles this is a nerve ending and this is responsible for sensitivity to light touch and notice it's located a little bit more superficial up of the skin because whenever you're lightly touched on your skin this is what is responsible for you feeling that sensation and then the next nerve ending is called the panzini corpuscle and it's these little pink little things whirly things right there and that is responsible for our sensitivity to pain and pressure so whenever you get pain on your skin or pressure this little guy is responsible for you filling that now we went over our diagram and let's do a little cup of quiz questions so let's see what it says the skin is composed of blank layers so whenever we were looking at our skin diagram how many layers do you remember that there were let's look at our choices we have a 3 B 2 C 2 and a half or D 4 now let's think about this because it's a little bit tricky you have your top layer which is your epidermis then you have your second layer which is your dermis and what did I say at the beginning of the video there's only two distinct layers because we remember a lot of people might want to put three because they're thinking that the hypodermis is part of the integumentary system but it's not so they don't consider that a layer so the skin only has two layers which are your epidermis and dermis so a C and D are wrong so we can mark those out and the answer is B - now take rest of this quiz on my website registered nurse Orion comm a link should pop up in the video and you can just click it and go and take the quiz and I hope this helped you for studying for your integumentary system a MP exam I hope you pass and be sure to check out my other a MP lecture tutorials and quizzes and thank you so much for watching and please subscribe to this YouTube channel