Term
What are the functions of skin? |
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Definition
1. Protection: a) maintain fluid levels b) stops entry of bacteria c) from injury d) impermeable to water e) aids in temp. regulation
2. Excretory: Sudoriferous glands (sweat glands) in skin secrete salts, urea, uric acid, and carbon dioxide onto skin
3. Sensations: Nerve receptors which are sensitive to the 4 basic senses- pain, touch, temperature, and pressure.
4. Vitamin D Production |
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Term
What are the 3 main layers of the skin? |
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Definition
Epidermis, Demis, and Subcutaneous |
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Term
What are the 4 sublayers of the epidermis and what is their functions? |
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Definition
1. Stratum Corneum: 12 to 15 keratinized cells. Keratin is a protein that makes skin tough. These cells are of this sublayer are dead and are constantly shed.
2. Stratum Lucidum: Thickens with friction. EX: a callous
3. Stratum Granulosum: Cells die here and is important to keratinization since keratin refills the dead cells.
4. Stratum Germinativum: Deepest layer of the epidermis. Only place where cell mitosis occurs, thus this is the place of new cell formation. |
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Term
What is the function of the dermis? |
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Definition
1. Made of dense irregular fibrous connective tissue. Sometimes called "true skin" because it is the strongest layer of the skin.
2. Embedded with nerve receptors, capillaries with blood, lymph vessels with lymph, hair follicles, sudoriferous glands, sebaceous glands and some muscles for facial expression.
3. Sebum is produced by sebaceous glands which lubricates surface of skin and hair.
4. Perspiration contains wastes and regulates our bodies temp. |
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Term
What is the function of the subcutaneous layer of skin? |
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Definition
1. Composed of adipose connective tissue which insulates, protects, and stores fat. |
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Term
What are skin derivatives and give some examples. |
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Definition
Skin derivatives grow from the same germ tissue as skin. Examples are hair, teeth, nails, and horns of animals. |
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