Welcome. Thanks for joining me today. In this lecture, we will begin our exploration of medical terminology as it relates to the integumentary system. Let's get started. The integumentary system is a medical term for your skin. The largest organ of the body. Your skin serves as your outer covering. The branch of medicine that specializes in the integumentary system is called dermatology. Let's begin by looking at the basic purposes of skin. But first, let's look at this adorable baby camel. Careful, they spit. The skin plays a primary role in protecting the body from the outside environment. This may include things like forming the first line of defense against germs and pathogens or preventing irritants from entering the body. As the first point of contact with your outside surroundings, the skin must be tough enough to handle regular bumps and scratches but gentle enough to sense changes in the environment. A second purpose of the skin involves maintaining homeostasis or a relatively stable internal environment. In particular, skin helps regulate body temperature as insulation. It can both warm the body by keeping heat trapped inside as well as allow for cooling through mechanisms like sweating. I suppose you could say that your skin is like the OG cooler. They thought they were innovative. Before we get much further in the discussion, let's go over some basic anatomy of the integumentary system. The epidermis is the outermost visible layer of the skin. It is made up of very thin layers of squamous cells. Squamous cells are thin and flat and overlap slightly like fish scales. Most interesting, there are minimal blood vessels in the epidermis, which is why superficial minor abrasions or scrapes do not always bleed. It's also why you can do this cool body trick. Not that I'm recommending it, but as long as you stick to the superficial epidermis, no blood, no pain. Back to the lecture at hand. Get it? At hand. The dermis is the middle layer of the skin. It is much thicker than the epidermis and mostly made up of thick strong fibers. This allows the skin to be pinched when resistant to tearing. It's a good thing if you have siblings. The dermis also contains hair follicles, nerves, and glands. As mammals, human bodies are covered with visible hair. A hair follicle holds the hair. Fun fact. All of the hair follicles on the human body are formed by the time we are just five months old in the womb. You will also find nerves within the dermis or the middle layer of the skin. They are responsible for things like detecting pressure, temperature, and pain. Glands or groups of cells that release fluid, are also found in the dermis. There are two main types of glands in the skin: sweat glands, which release sweat, and sebaceous glands that secrete oil. Sweat cools the body and gets rid of waste. Sebum or oil lubricates the skin. Sebum also waterproofs the skin. Don't believe me? Watch the water beat up on your skin while dancing with abandon in the rain. Odds are, other people will watch you too, but who cares? Life is made to live, people. A final accessory structure of the skin. Nails are found at the ends of fingers and toes. They are made up of this hard substance known as keratin and serve to protect the ends of our digits, which are most susceptible to damage as we interact with our environment. Nails can also serve as a good base for movement and a great way for self-expression. I'm now for a brain break. Back to the topic at hand, skin. We will continue our exploration by learning some new word roots related to the integumentary system. Fun fact. Your skin constantly sheds dead cells about 30-40,000 cells every minute. That's nearly nine pounds per year. I think most of that goes into our mattresses. Mattress protector? Yes, please. There are multiple word roots that all mean skin. They include cutane/o, derm/o, and dermat/o. You can find them in words like cutaneous, epidermis, and dermatology. As with skin, there are three new word roots that mean fat. They include adip/o, lip/o, and steat/o. They can be found in words like adipose tissue or liposuction and steatosis. Fat gets a bad rap. While we definitely don't want an overabundance, an inadequate amount of fat can be just as unhealthy. Fat is a necessary component of skin and serves as insulation to help maintain body temperature. It also plays a role in hormone function. Go ahead, indulge every once in a while. All things in moderation. For the word hair, you should know both pil/o and trich/o. They can be seen in the words piloid and hypertrichosis. Hidr/o is a word root that means sweat. It can be seen in the term hyperhidrosis. Hydration makes me think of fluid intake, which makes me think of fluid loss, which makes me think of sweating. Weird and wonderful in this brain of mine. Whatever works for you, don't forget to hydrate, and that hidr/o means sweat. Meaning scale, squam/o can be found in the word squamous. Squamous describes the skin cells of the epidermis, which overlap like fish scales. Under a microscope, we all look like beautiful mer-people. Nail, as in fingernail or toenail, has two common word roots. Onych/o and ungu/o. Words like onychectomy and subungual demonstrate their use. Recall that oil is responsible for moisturizing and waterproofing the skin. The roots seb/o and sebace/o both mean oil, as in sebum and sebaceous gland. Did you know that we all have relatively the same number of melanin-producing cells or melanocytes? The melanin production itself changes. The next roots pertain to abnormal skin texture and color. Skin will tan with UV radiation exposure like sun or tanning beds because the melanocytes produce more melanin. They darken to protect the cell nucleus, which they cover from harmful UV rays and thus prevent damage to the cellular DNA. Melanocytes are like your own nuclear umbrella attempting to shield your DNA from the sun. How cool? These roots pertain to skin texture. Kerat/o means hardness, as in keratin found in your nails. Xer/o means dryness, as in xeroderma or dry skin. Crypt/o means hidden as in onychocryptosis or an ingrown or hidden toenail. Finally, these word roots pertain to skin color or appearance. Leuk/o means white, as in leukocytes which are white blood cells. Erythr/o means red, as in erythroderma, which you might see with a rash or allergic reaction. Xanth/o means yellow, as in xanthoderma seen in jaundice. Melan/o means black, as in melanoma which is a dark-colored skin cancer. As with all good things, this lecture too must come to an end. I know you are sad. Thanks for exploring introductory terms and roots related to the integumentary system with me. See you next time
