Integument Flashcards
1
Q
Integument size
A
- 7-8% of body weight
- 1.5-2 m2
2
Q
layers of integument
A
- epidermis: stratified squamous epithelium
- dermis: dense irregular connective tissue
- hypodermis: adipose connective tissue
3
Q
integument functions
A
- protection
- prevention of water loss
- temperature regulation
- metabolic regulation
- immune defense
- sensory reception
- excretion/secretion
4
Q
epidermis
A
- most superficial
- avascular
- keritanized stratified squamous epithelium (4-5 layers of distinct cell types)
5
Q
keratin
A
water-insoluble protein
6
Q
epidermal strata (layers)
A
deep to superficial
- stratum basale
- stratum spinosum
- stratum granulosum
- stratum lucidum
- stratum corneum
7
Q
stratum basale
A
- only one that undergoes mitosis
- one layer of cells adjacent to dermis
has keratinocytes, melanocytes, tactile cells, and dendritic cells
8
Q
keratinocytes
A
- most abundant
- produce keratin to waterproof skin
9
Q
melanocytes
A
- long, branches cytoplasmic processes
- produce melanin (black, brown, or yellow) that absorbs UV light to prevent DNA damage and reducing some forms of skin cancer
10
Q
tactile cells
A
- sense touch
11
Q
dendritic cells
A
- immunity
12
Q
stratum spinosum
A
- several layers thick
- daughter cells from stratum basale
- differentiate into non dividing highly specialized keratinocytes
- may see a rare mitotic cell
13
Q
stratum granulosum
A
- 3-5 layers of keratinocytes
- cytoplasm filled with keratin filaments (grainy)
- organelles begin to degrade
- fully keratinized cells are dead but strong and water-insoluble
14
Q
stratum lucidum
A
- thin, translucent region
- 2-3 layers thick
- only in thick skin (soles of feet and palms of hands)
- cells lack organelles, filled with eleidin, a transparent intermediate product of keratin maturation
15
Q
stratum corneum
A
- most superficial layer
- can be a few to 50 layers tick based on location
- comprised only of dead keratinocytes (korneocytes)
- slogged off by abrasion= dust
- desquamation= when korneocytes detach, die, and fall of. the shedding of skin
16
Q
epidermal skin colour based cells
A
- melanin
- hemoglobin
- carotene
17
Q
melanin
A
- brown-black pigment produced by melanocytes
- genetic inheritance
- increases with UV light exposure
- protects nuclear DNA
18
Q
hemoglobin
A
- blood pigment
- causes light complexions to look pink
19
Q
carotene
A
- yellow-orange pigment from food that builds up in the skin
20
Q
What determines skin tone
A
- by melanocyte activity not melanocytes number/density
- more active= darker skin and produces more melanin
21
Q
nevus
A
- localized overgrowth of melanocytes
- a mole
22
Q
epidermal skin markings
A
- nevus
- hemangioma
- friction ridges
23
Q
hemangioma
A
- proliferation of blood vessels
- strawberry= in childhood, may disappear
- port wine= in adults, may persist
24
Q
friction ridges
A
- folds of epidermis/dermis on fingers, palms, soles, and toes for grasping
- causes us to leave fingerprints
25
Q
dermis
A
- deep to epidermis
- vascular
- 2 layers
1) papillary (superficial)
2) reticular (deeper)
many collagen fibres
contains blood vessels, glands, hair follicles, nail roots, sensory nerve endings, and smooth muscle
26
Q
papillary layer of dermis
A
- directly below stratum basal of epidermis
- dermal papillae and epidermal ridges interlock to increase surface area between dermis and epidermis
- dermal papillae contain capillaries that supply nutrients to avascular epidermal cells
27
Q
reticular layer of dermis
A
- majority of dermis
- comprised mainly of dense irregular connective tissue with large bundles of collagen fibers, blood vessels, glands, hair follicles, and nerves
- collagen bundles help connect dermis to underlying hypodermis
28
Q
lines of cleavage
A
- lines in deep dermis formed by orientation of collagen bundles
- incisions heal faster when parallel to lines
29
Q
innervation
A
- nerve fibers present in dermis
30
Q
functions of innervation
A
- tactile receptors
- control blood flow
- control glandular secretion
31
Q
blood supply
A
- epidermis: avascular
- dermis: vascular
- important in controlling body temperature
- vasoconstriction & vasodilation
32
Q
vasoconstriction & vasodilation
A
- constriction: narrowing of blood vessels to preserve core body heat
- dilation: widening blood vessels releases body heat and lowers body temperature
33
Q
hypodermis (subcutaneous layer)
A
- deep to integument (not rly part of)
- areolar and adipose connective tissue
34
Q
hypodermis functions
A
- protects underlying structures
- stores energy
- thermal isulation
35
Q
structures that grow from epidermis
A
- nails
- hair
- glands
36
Q
nails
A
- derived from stratum corneum
- cells densely packed together filled with parallel fibers of hard keratin
- nail plate has whitish free edges, a pinkish nail body, and nail root
- nail body covers a layer of epidermis called nail bed
- nail bed appear pink cause of underlying capillaries
37
Q
nail body
A
- flat keratinized cells protecting digit
38
Q
nail bed
A
- live epidermal cells under nail body
39
Q
nail root
A
- region hidden by cuticle
40
Q
nail matrix
A
- thickened newly growing part of nail bed
41
Q
lunula
A
- white semilunar proximal area of nail body caused by thickened underlying stratum basale obscuring capillaries in dermis
42
Q
hair
A
- column of keratinocytes growing from follicles deep in dermis or hypodermis
- hair shaft, follicle, and subaceous gland
43
Q
hair shaft
A
- exposed
- completely keratinized
44
Q
hair follicle
A
- epidermal fold surrounding the hair
- wrapped in nerves
45
Q
sebaceous gland
A
- secretes sebum into hair follicle
- moisturizes hair and skin
46
Q
hair bulb
A
- swelling at bottom of follicle filled with dividing keratinocytes
- increase in hair matrix causes hair growth
- anchors hair root to dermis
47
Q
hair papilla
A
- connective tissue, nerves, and blood vessels below follicle that supports keratinocytes
48
Q
arrestor pili
A
- involuntary smooth muscle attached to hair shaft
- responds to emotional states and cold temps by contracting, standing hair up, and producing goose bumps
49
Q
functions of hair
A
- protection
- heat retention
- facial expression
- sensory reception
- visual identification
- chemical signal dispersal
50
Q
skin exocrine glands
A
sweat glands and specialized gland types
51
Q
sweat glands
A
- produces watery solution
- eccrine and procaine sweat glands
52
Q
specialized
A
- sebaceous: produce oily secretions
- ceruminous glands: produce ear wax
- mammy: produce milk
53
Q
eccrine (merocrine) sweat glands
A
- simple coiled tubular glands that secrete into a duct with a pore on skins surface
- secretion is 99% water, clear, and controlled by nervous system
- numerous on forehead, palms, and soles
54
Q
functions of eccrine (merocrine) sweat glands
A
- thermoregulation
- secretion
- protection
55
Q
aprocine sweat glands
A
- simple coiled tubular glands that secrete into hair follicles around nipples (areolar), armpits (axillae), groin (pubic), and anus (anal)
- secretion is thick, cloudy, proteins and lipids
- leads to bacterial growth causing body odour (sweat itself doesn’t smell)
56
Q
sebaceous glands (holocrine)
A
- secrete oily sebum into hair follicles
- lubricates hair and skin
- relatively inactive during childhood
- sex hormone at puberty cause secretions to increase significantly
