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21 Cards in this Set
- Front
- Back
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Functions: Protection |
- Bacterial invasion/ physical injuries/excessive fluid loss - Oily secretions stop the growth of pathogenic invaders - Skin is rugged/ elastic -- Helps prevent underlying parts from injury - Waterproofed due to protein keratin |
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Functions: Body Temperature
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- Normal body temperature is 37 C (98 F) - Dilation and constriction of the blood vessels and the activity of the sweat glands |
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Functions: Receptors of Stimuli |
- Contains many sense receptors--Indicate heat, cold, pain, touch, and pressure - Special receptors called exteroceptors relay information about the environment to the brain so that changes can be made to prevent or minimize injury |
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Functions: Metabolic Activity |
- Ultraviolet rays assist skin cells in producing vitamin D precursor, which is necessary for normal bone growth and development |
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Functions: Blood Reservoir |
- About 5% of the body's blood volume is in the skin - When extra blood is needed in other areas, the nervous system constricts the blood vessels in the skin; therefore, more blood is free to flow into other areas of the body |
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Excretion |
- Although most of the "wastes" of metabolism i.e., ammonia, urea, and uric acid are excreted in urine, some is eliminated as sweat - Excess water and salts are also excreted by the skin |
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Layers of the Skin |
- The skin consists of two main layers, the epidermis and the dermis. - The hypodermis (subcutaneous layer) is not really part of the skin; it consists of fat and areolar connective tissue |
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Layers of the Skin: Epidermis (1) |
- Outer layer-- Consists of stratified squamous epithelium - Closely packed cells protect the body from excessive water loss/ invasion by microorganisms - Surface cells are dead (about 30 layers of them), but are constantly being replaced |
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Layers of the Skin: Epidermis (2) |
- Avascular (no blood supply) - Deep layers of the epidermis contain a dark pigment called melanin - Surface contains keratin |
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Layers of the Skin: Epidermis (Structure) |
TOP-BOTTOM - Stratum Corneum - Stratum Luciderm (found in the palms and soles) - Stratum Granulosum - Stratum Spinosum - Stratum Basale Try thinking CORi's GRANny SPINs BASketballs] |
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Layers of the Skin: Dermis |
- Called the corium - Found beneath the epidermis - Composed of strong, flexible loose and dense connective tissues - Blood vessels, nerves, lymph vessels, hair follicles, and sweat glands are embedded in the dermis |
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Dermis: Papillary Layer |
- Composed of papillae (projections)--that extend into the epidermis. - Blood vessels, nerve endings, and sensory receptors, extend into closer proximity to the epidermis on the surface - Distinct patterns (ridges) that are formed by the papillae=fingerprints |
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Dermis: Reticular Layer |
- Attached to the underlying hypodermis (subcutaneous layer) - "Strong" part of the dermis - Leather is made from this layer of certain animals |
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Sudoriferous (Sweat) Glands |
- Secrete sweat - Found in the dermal regions of the skin - Abundant in the palms and soles - Apocrine glands and eccrine glands are the two types of sweat glands |
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Sweat Glands: Apocrine Glands |
- Associated with hair follicles that are found in the axillary regions (armpits) and genital areas - Become active during puberty - Accumulation of sweat is sometimes changed by bacteria into what's known as "body odour" |
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Sweat Glands: Eccrine Glands |
- Not associated with hair follicles - Function throughout lifetime - Found all over the body and are especially numerous on the forehead, upper lip, palms, and soles. |
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Sebaceous (Oil) Glands |
- Secrete sebum (oily substance) - Associated with hair follicles - Found in all areas of the body that have hair - Sebum helps to waterproof the hair and skin - Sebum also inhibits the growth of bacteria on the surface of the skin |
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Nails |
- Epidermal cells converted into keratin. - Has a free edge, a nail body (visible part), a nail root, and an eponychium (cuticle) - The whitish crescent-shaped part is called the lunula. - Protect their underlying tissues from the environment and from trauma. Fingernails also help in grasping and picking up small objects. |
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First-Degree Burn |
- Superficial cells of the epidermis are destroyed - Skin is inflamed and tender - e.g., sunburn |
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Second-Degree Burn |
- Superficial and deeper cells of the epidermis are destroyed (dermis may be affected) - Blisters on he skin and the burn is painful |
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Third-Degree Burn |
- All epidermal and dermal cells are destroyed - Skin is charred--no sensation at all (nerve endings have been destroyed) - The immediate threat to life is the loss of body fluids--several litres per day |
