Integumentary System: Vocabulary Study Guide
Why Learning Skin Vocabulary Terms is Important
The skin, hair and nails as well as certain glands make up the largest organ system in the body. Learning the vocabulary and terms associated with the skin and its accessory organs will help you understand your reading material making it easier to study.
The skin is made up of epithelial tissue whose chief function is to line and cover the insides of body organs like your esophagus, stomach and blood vessels as well as everything else on the outside. In fact one of the skin's most important functions is to serve as the body's primary defense mechanism protecting the body from outside invaders. Before learning the functions of the skin and its accessory organs, it is important to learn the vocabulary associated with it. Learning the vocabulary terms of the integumentary system will help you master the anatomy and better understand how it functions.
The skin has two main layers to protect the body. The outermost layer is called the epidermis which is several layers thick - especially on the palms and soles of your feet. In some areas of the body, the epidermis is thin - like the delicate skin that covers your eyelid.
The second layer of the skin is the dermis. Most blood vessels, nerves, glands and hair roots are located in the dermis. The dermis is mostly made up of a substance called matrix . Matrix contains fibers made up of collagen which gives skin its strength and elastin which helps make the skin stretchy or pliable. Also in the matrix are reticular fibers. These fibers help bind both the collagen and elastin fibers together. Beneath the dermis lies another layer called the hypodermis. This layer is mostly made up of fat. The hypodermis cushions and protects the inner organs and provides insulation.
All kinds of skin cells live in the epidermis. The most common skin cells are keratinocytes. These cells form in the bottom layer of the epidermis, push their way up through the skin surface and are eventually shed. They make a protein called keratin which helps waterproof your skin. Other skin cells make a substance called melanin. They produce melanin to protect the other skin cells in the body from getting too much ultraviolet light. Langerhan's cells are special skin cells that help the immune system fight foreign invaders.
The skin has two types of glands. Sebacious glands make an oily substance called sebum and are located everywhere except the palms and soles. You can find these glands anywhere you have hair on your body; sebacious glands connect to hair follicles keeping the hair moist and supple. These glands can clog up and cause a severe case of pimples called acne. The other types of skin glands are sudiferous glands, but we know them as sweat glands. These glands become active when you exercise or are under emotional stress. Sweat glands also help your body regulate temperature.
Hair and nails are the accessory organs of the integumentary system and are composed of the protein keratin. The part of the hair you see on the outside is called the hair shaft . The exposed part of the nail you see is called the nail bed. Neither the nail bed nor the hair shaft is made of living tissue which is why it doesn't hurt to get a haircut or trim your nails. The living parts of these structures -the hair follicle and the nail matrix- lie in or near the dermis.
Test Your Knowledge
Now that you know some basic vocabulary terms associated with the skin, test your knowledge. View and download the matching activity worksheet called "Integumentary Vocabulary Worksheet" at
http://images.brighthub.com/media/ACECE4_activities-for-the-integumentary-system.docx from the media section.