Term
| 5 functions of the integumentary system |
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Definition
| 1. protection from mechanical, chemical, and thermal damage 2. insulates and cushions underlying body tissues 3. protection from bacterial invasion 4. prevention of water loss 5. site of vitamin D synthesis |
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Term
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Definition
1. epidermis (epithelium tissue)
2. dermis (underlying connective tissue) |
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Term
| hypodermis (superficial fascia) |
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Definition
| layer composed of adipose tissue that is deep to the dermis, not considered part of the skin |
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Term
| keratinocytes (4 characteristics) |
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Definition
| 1. produce keratin fibrils 2. most abundant epidermal cells 3. mitotically active 4. located in the stratum basale |
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Term
| melanocytes (2 characteristics) |
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Definition
1. cells that produce melanin (brown to black pigment)
2. located in the stratum basale |
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Term
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Definition
pigment provides protective layer for nuclei of cells in deeper epidermal layers
when exposure to UV and UVB radiation occurs, skin produces melanin |
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Term
| epidermal dendritic cells (Langerhans cells) |
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Definition
1. act as macrophages to engulf and digest pathogens
2. Located in the stratum spinosum |
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Term
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Definition
1. form sensitive touch receptors at the epidermal-dermal junction with sensory nerve endings
2. Located in the stratum basale |
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Term
| Layers of the epidermis (deep to superficial) |
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Definition
1. stratum basale
2. stratum spinosum
3. stratum granulosum
4. stratum lucidum
5. stratum corneum |
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Term
| stratum basale (basal layer) (# of layers, and contents) |
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Definition
1. single layer of cells
2. contents: Keratinocytes, Melanocytes, Merkel cells |
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Term
| stratum spinosum (# of layers, and contents) |
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Definition
1. Several layers of cells
2. Cells are connected by desmosomes which cause the cells to appear “spiny” during histological preparation
3. Tonofilaments: intermediate filaments made of pre-keratin protein
4. Langerhans’ cells |
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Term
| stratum granulosum (# of layers and contents) |
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Definition
| 1. 3-5 layers of cells 2. Lamellated granules: contain Glycolipids that make the epidermis water-proof. 3. keratohyaline granules: contain the tough, insoluble protein, Keratin, which makes the epidermis tough and abrasive-resistant |
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Term
| stratum lucidum (# of layers and contents) |
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Definition
1. Thin, translucent layer of dead cells
2. Present only in thick skin – palms, soles |
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Term
| stratum corneum (# of layers and contents) |
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Definition
1. 20-30 layers of dead, flat cells
2. Dead cells are impregnated with glycolipids and keratin to provide a tough, durable, water-proof “coat”.
3. Replaced every three to four weeks |
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Term
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Definition
1. papillary layer
2. reticular layer |
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Term
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Definition
| more superficial dermal region composed of areolar tissue |
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Term
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Definition
| finger-like projects from the papillary layer that make it uneven, responsible for fingeprints |
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Term
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Definition
| deepest layer of skin composed of dense irregular connective tissue, contains blood vessels, sweat and sebaceous glands, and pressure receptors |
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Term
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Definition
| visible attached portion of nail |
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Term
| nail free edge (hyponchium) |
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Definition
| portion of nail that grows away from the body |
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Term
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Definition
| part of nail that is embedded in the skin and adheres to the epithelial nail bed |
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Term
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Definition
| skin that overlaps the borders of the nail |
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Term
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Definition
| cuticle--thick proximal nail fold |
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Term
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Definition
| extension of stratum basale beneath the nail |
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Term
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Definition
| thickened proximal part of the nail bed containing small germinal cells responsible for nail growth, cells become keratinized and die |
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Term
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Definition
| proximal region of thickened nail matrix, which appears as a white crescent |
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Term
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Definition
| structure consisting of a medulla, central region surrounded by a cortex and protective cuticle |
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Term
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Definition
| portion enclosed within the follicle |
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Term
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Definition
| portion of hair projecting from the scalp surface |
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Term
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Definition
| collection of well-nourished germinal epithelial cells at the basal end of the follicle |
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Term
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Definition
| structure formed from both epidermal and dermal cells that surrounds a hair root |
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Term
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Definition
| dermal tissue that protrudes into the hair bulb |
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Term
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Definition
| small bands of smooth muscle cells that connect each hair follicle to the paillary layer of the dermis, muscles can contract to form goose bumps and cause hair to stand upright |
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Term
| 2 types of sweat (sudoriferous) glands |
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Definition
1. eccrine glands
2. apocrine glands |
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Term
| eccrine glands (merocrine sweat glands) |
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Definition
1. distributed all over body
2. produce clear perspiration
3. under control of nervous system
4. important part of heat regulating apparatus by removing body heat through sweat |
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Term
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Definition
1. located in axillary and genital areas
2. secrete milky protein and fat rich substance that is a nutrient for microorganisms found on skin
3. glands enlarge and recede with phases of a woman's menstrual cycle |
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Term
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Definition
Location: reticular layer
function: pressure receptors |
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Term
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Definition
location: papillary layer
function: pain and touch receptors (free nerve endings) in hairless skin |
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