Term
| Skin: 2 parts and an underlying functionally related part |
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Definition
1. epidermis = superficial region, thick epithelium (integumentary system)
2. dermis = underlying the epidermis, fibrous connective tissue, (integumentary system)
3. hypodermis: fatty layer underlying dermis, not part of the integumentary layer |
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Term
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Definition
1. cushions and insulates the deeper body organs
2. protects the body from bumps, scrapes and cuts
3. protects from harmful chemicals, heat, cold and bacteria
4. miniature excretory system
5. sweat glands help regulate body temperature
6. screens out harmful uv rays
7. contains sensory receptors keeping us aware of the condition of the body surface |
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Term
| 4 main cell types of the epidermis |
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Definition
1. keratinocytes = most abundant, produces keratin-fibrous protein-giving skin protective qualities. produce antibodies and enzymes. arise from basal layer, dead at surface
2. merkel cells = in the stratum basale and associated with nerve endings
3. malanocytes = 10-25% of stratum basale - makes melanin - clusters on superficial side of keratinocytes
4.langerhans = in the stratum spinosum just superior to the stratum basale, take up foreign proteins(antigens) and take them to the lymph nodes where they are destroyed by killer T lymphocytes |
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Term
| 5 layers of the epidermis (superior to deep) |
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Definition
1. stratum corneum
2. stratum lucidium (only in thick skin)
3.stratum granulosum
4. stratum spinosum
5. stratum basale |
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Term
| Stratum basale (basal layer): 4 qualities |
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Definition
1. deepest layer of the epidermis
2. cells actively divide (mitosis)
3. attached to the dermis
4. only layer containing merkel cells and melanocytes |
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Term
| Stratum spinosum (spiny layer) |
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Definition
1. spiny appearance due to artifacts of histological preparation
2. contains thick bundles of intermediate filaments = tonofilaments
3. contains star shpaed langerhans' cells |
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Term
| stratum granulosum (granular layer) |
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Definition
1. contains keratinocytes and tonofilaments
2. tonofilaments: contains keratohyaline granules (helps form keratin) and lamellated granules (contains waterproofing glycolipids) |
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Term
| stratum lucidum (clear layer) |
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Definition
1. only in thick skin
2. consists of a few rows of flat dead keratinocytes |
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Term
| statum corneum (horny layer) |
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Definition
1. thick layer of dead keratinocytes and thickened plasma membranes
2. protects skin against abrasion and penetration. |
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Term
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Definition
1. second major layer of the skin
2. strong, flexible connective tissue
3. richly supplied with blood vessels and nerves
4. has 2 layers: papillary (superficial 20%) and reticular layer (deeper 80%) |
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Term
| Integumentary structure and and function of hypodermis |
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Definition
1. deep to the skin - also called superficial fascia
2.contains areolar and adipose connective tissue
3.anchors skin to underlying structures
4.helps insulate the body |
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Term
| skin color: three contributing pigments |
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Definition
1. melanin - most important made from tyrosine
2. carotene - yellowish made from carrots and tomatoes
3. hemoglobin - caucasian skin contains little melanin and allows blood to show through |
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Term
| Appendages of the skin: Hair |
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Definition
1. flexible strand of hard keratinized cells
2. parts = root and shaft
3. 3 layers = medulla, cortex, cuticle |
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Term
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Definition
extend from epidermis to dermis
1. hair bulb - deep but expanded end of hair follicle
2. root plexus - knot of sensory nerves around hair bulb |
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Term
| Wall of hair follicle: 2 parts |
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Definition
1. outer connective tissue root sheath (derived from the dermis)
2. inner epithelial tissue root sheath (derived from the epidermis) |
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Term
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Definition
| bundle of smooth muscle - hair stands erect when arrector pili contracts |
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Term
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Definition
1. vellus hairs - body hairs of women and children
2. terminal hairs - hair of scalp, axillary, and pubic areas |
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Term
| Hair thinning and baldness |
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Definition
1. due to aging (thinning)
2. male pattern baldness |
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Term
| Sebaceous Glands: location, how secretion happens and the function of sebum |
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Definition
1. occurs over entire body except palms and soles
2. simple alveolar glands with a single duct. alveoli are filled with cells that become engorged with oily lipids and burst apart. process called holocrine secretion.
3. collects dirt, softens and lubricates hair and skin. |
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Term
Sweat glands (sudoriferous glands):
what sweat is, what it's made of and the 2 types |
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Definition
1. Sweat – is a blood filtrate
2. 99% water with some salts
3. Contains traces of metabolic wastes. Two types of sweat gland
1. Eccrine gland
Most numerous – produce true sweat
2. Apocrine gland
Confined to axillary, anal, and genital areas
Produce a special kind of sweat |
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Term
| Nails: what it is, what it's made of, 5 parts of the nail |
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Definition
1. scale-like modification of epidermis
2. Made of hard keratin
3. Parts of the nail
Free edge
Body
Root
Nail folds
Eponychium – cuticle |
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