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19 Cards in this Set
- Front
- Back
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Epidermis |
5 layers. Epithelial tissue. Avascular. Keratinoctyes. Replaced every 25-40 days |
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5 layers of the epidermis |
Corneum, lucidum, granulosum, spinosum, basale |
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Dermis |
Underlies epidermis. Varies in thickness around the body- thicker on palms and soles, thin on eyelids and lips. Two regions. |
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Regions of the dermis |
Papillary and reticular |
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Hypodermis |
Anchors skin to underlying structures. Contains adipose tissue for cushion and insulation. Contains nerve endings. |
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Sebaceous glands |
Connected to hair follicles. Secretes sebum- lubrication, antibacterial. More active in puberty |
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Sweat glands |
Merocrine/eccrine, apocrine |
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Merocrine/eccrine glands |
Most common glands. Ducts empty on to surface of skin. High water content. Primary function is to cool the body |
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Apocrine glands |
Ducts empty into hair follicles. Found around groin and axilla (armpits). Decomposes to form odor. Most active in puberty |
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Arrector pili muscle |
Involuntary smooth muscle. Attaches hair follicle and epidermis. Contracts in response to fear, cold and touch. "Goose bumps" |
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6 main functions of the skin |
Sensation, heat regulation, absorption, protection/immunity, excretion, vitamin D synthesis |
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Sensation |
Receptors in the dermis are stimulated in response to touch, pain, temperatur, vibration, texture and pressure |
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Heat regulation |
Responses are vasodilation when hot and vasoconstriction when cold |
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Vasodilation |
When temperature is high, blood vessels dilate to release more heat through the skin. Sweat glands are activated |
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Vasoconstriction |
When temperature is low, blood vessels constrict and reduce heat loss through the skin. Skin becomes pale. |
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Absorption |
Substances must be lipid soluble for this to occur |
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Protection/Immunity |
Prevents entry of foreign substances. 'acid mantle'. Melanin. Adipose tissue. |
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Excretion |
Waste is removed from the body via sweat glands |
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Synthesis of vitamin D |
UV light effects a substance in the skin which is converted to vitamin D in the liver and kidneys. Required for absorption of calcium and phosphorous |
