Ch 5 FAP Flashcards
1
Q
2 parts of the integumentary system
A
-cutaneous membrane (skin)
-accessory structures
2
Q
Components of cutaneous membrane
A
- outer epidermis- superficial ET
-inner dermis- connective tissues
3
Q
Accessory structures
A
- originate in the dermis
- extend through the epidermis to skin surface ex hair, nails, exocrine glands
4
Q
Functions of the integumentary system
A
- protection
- excretion of salts, water, organic wastes
-maint of body temp - production of melanin & keratin
- synthesis of vit D
- storage of lipids
- detection of touch, pressure, pain
- coordination of immune response
5
Q
Keratin ( keratinocytes)
A
Is a tough, fibrous protein that is also the basic structural component of hair and nails
6
Q
Thin skin
A
Contains four layers of of keratinocytes, most of the skin on the body
7
Q
Thick skin
A
Has 5 layers of keratinocytes found on the palms and soles of feet
8
Q
Five strata ( layers) of keratinocytes of the epidermis
- from basement membrane to free surface
A
- stratum basale
- stratum spinosum
- stratum granulosum
- stratum lucidum
- stratum corneum
9
Q
Stratum basale ( germinativum)
A
- attached to basement membrane by hemidesomosomes
-layer of epidermis that touches the dermis - contains epidermal ridges which lie next to dermal papillae
10
Q
Specialized structures of the stratum basale
A
-tactile discs- merkel cells have sensory nerve endings respond to touch
- melanocytes- contain pigment
11
Q
Spinonsum
A
Spiny layer
- 8-10 layers keratinocytes bound by desmosomes
- produced by division of cells in basale
- contains dendritic cells which are active in the immune response
12
Q
Stratum granulosum
A
The granular layer
- 3-5 layers of keratinocytes produced from cells from spinosum
-most cells stop dividing and produce keratin and keratohyaline after production of proteins cells die.
13
Q
Keratohyalin
A
Kerato/hyalin strong keartin
- forms dense granules and promotes cellular dehydration and cross linking of keratin fibers
14
Q
Stratum lucidum
A
The clear layer
- found only in the thick skin
- covers granulosum
15
Q
Stratum corneum
A
Horny layer
- exposed surface of the skin, water resistant
-15-30 layers of keratinized cells
-new cells move from the basale to corneum in 7-10 days and exposed cells are shed after 2 wks
16
Q
Water is lost by 2 ways
A
- insensible perspiration
-sensible persperation
17
Q
Sensible perspiration
A
Where water is excreted by the sweat glands
18
Q
Insensible persperation
A
Water is diffused across the corneum and evaporates average of 500ml daily
19
Q
Epidermal growth factor EGF
A
-peptide growth factor produced by the salivary glands and duodenum and used in labs to grow skin grafts
20
Q
Functions of EGF
A
- promotes division of basal cells
-accelerates keratin production - stimulates epidermal repair and glandular secretion
21
Q
Dermis
A
Located between the epidermis and subcutaneous layers and anchors epidermal accessory structures
22
Q
2 components of the dermis
A
- papillary layer (outer)
- reticular layer (deeper)
23
Q
Papillary layer
A
-Consists of areolar tissue
- contains capillaries, lymphatic vessels and sensory neurons
-named for the dermal papillae that project between the epidermal ridges
-dermatitis affects this layer
24
Q
Reticular layer
A
- consists of D. Irregular CT
- contains collagen and elastic fibers
-fibers combine with papillary layer so the boundary is indistinct
25
Skin damage
- loss of turgor is caused by dehydration (temp), aging, hormones, UV radiation
26
Tension lines
- resist forces applied to the skin and are produced by parallel bundles of collagen and elastic fibers in the dermis.
- a cut made parallel to a tension line remains shut and heals well, a cut made perpendicular to one may remain open and/or not heal well.
27
Cutaneous plexus
Deep network of arteries along the reticular layer
28
Subpapillary plexus
Network of small arteries in the papillary layer
-capillaries drain into small veins that lead to larger veins in the subcutaneous layer
29
Contusion
Bruise caused by damaged blood vessels in the dermis
30
Functions of the nerves in the skin
-control blood flow
-adjust gland secretion rates
-monitor sensory receptors
31
Sensory receptors respond to
- light touch- tactile (meissner) corpuscles, in the dermal papillae
- deep pressure and vibration- lamellar ( pacinian) corpuscles, in the reticular layer
32
Subcutaneous layer
Aka hypodermis
-connected to reticular layer by CT
- stabilizes position of the skin
- primarily adipose tissue
-large arteries and veins in superficial region
-distribution of SC fat is determined by sex
33
2 pigments of skin color
- melanin
-carotene
34
Melanin
- red/yellow or brown/black pigment
-stored in intracellular vesicles (melanosomes)
- transferred to keratinocytes
- protects skin from UV radiation
35
Carotene
-orange-yellow pigment
-found in orange veggies
-can be converted to vit A, required for maint of ET and synthesis of photoreceptor pigments in the eye
36
Jaundice
- build up of bile produced by liver
- skin and whites of eyes may turn yellow
37
Pituitary tumor
Excess MSH increases production of melanin
38
Addison’s disease
Causes pituitary gland to release excess ACTH, which has an effect similar to MSH
39
Vitiligo
Loss of melanocytes causing loss of color
40
Vit D 3
Aka cholecalciferol
-produced by epidermal cells in presence of UV radiation
-liver & kidneys convert vit d3 into calcitriol
-insufficient vit d3 can cause rickets
41
Calcitriol
Essential for absorption of calcium and phosphate ions by small intestine
42
Hair is not found
-palms &sides of fingers
-sides & soles of feet, sides of toes
- lips
-portions of external genitalia
43
Functions of hair
- protect & insulate
- guard openings from particles and insects
- serve as sensory receptors
44
Hair follicles
- extend deep into the dermis and produce nonliving hair
- wrapped in a dense CT sheath
- base is surrounded by sensory nerves
45
Root hair plexus
Is a layer of sensory nerves that surrounds a hair follicle which makes us feel our hair move.
46
Arrector pili muscle
- involuntary smooth muscle whose contraction makes hair stand on end/straight up and produces goosebumps
47
Hair root
Portion that anchors into the skin
48
Hair shaft
Upper/outer part of the hair
49
Layers of a strand of hair
- medulla- central core
- cortex- intermediate layer
-cuticle- surface layer
50
medulla
central core
51
cortex
intermediate layer
52
cuticle
surface layer
53
Layers of the follicle
- internal root sheath
-external root sheath
-glassy membrane
54
Hair bulb
Beginning of hair production
55
Hair papilla
CT containing capillaries and nerves
56
Hair matrix
@ base of bulb formed from layer of ET cells , as cells divide hair is pushed up and out through the skin
57
Hair growth cycle
As hair grows the root is firmly attached to matrix at the end of the cycle the follicle becomes inactive and named club hair. When a new cycle starts the club hair is pushed to the top and shed. Average growth is 0.33 mm a day and average shed is 100 head hairs a day. Dogs shed about 2000.
58
Types of hairs
- vellus hairs- soft, fine hairs that cover most of the body
- terminal hairs- heavy pigmented hairs on head, eyebrows, lashes and other parts after puberty
59
vellus hairs
soft, fine hairs that cover most of the body
60
terminal hairs
heavy pigmented hairs on head, eyebrows, lashes and other parts after puberty
61
Hair color
- produced by melanocytes at hair matrix
- determined by genes
62
Exocrine glands of the skin
-sebaceous glands (oil glands) - discharge sebum (lipid secretion) into hair follicles, lubricates and protects hair shaft and inhibits bacterial growth.
— holocrine glands
-sweat glands
—apocrine sweat glands
— eccrine sweat glands
63
sebaceous glands
(oil glands) - discharge sebum (lipid secretion) into hair follicles, lubricates and protects hair shaft and inhibits bacterial growth.
— holocrine glands
64
sweat glands
—apocrine sweat glands
— eccrine sweat glands
65
Types of sebaceous glands
-Simple branched alveolar glands associated with hair follicles
- sebaceous follicles - large, not with hair, discharge sebum directly onto skin, located on the face, back, chest, nipples, external genitalia
66
sebaceous follicles
- large, not with hair, discharge sebum directly onto skin, located on the face, back, chest, nipples, external genitalia
67
Apocrine glands
-found in the armpits, around nipples, and pubic region
- secrete products into hair follicles via merocrine secretion
-produce sticky cloudy secretions ,nutrient source for bacteria that produce odors
- surrounded by myoepthelial cells, squeeze secretions out of glands in response to hormonal or nervous signals
68
Eccrine sweat glands
Aka merocrine
-coiled tubular glands that discharge directly onto skin surface sensible perspiration
-widely distributed on body surface especially on hands and feet
- secretions are 99% saline
69
Functions of eccrine sweat glands
- cooling of skin to reduce body temp
- expelling water and electrolytes
-providing protection from environmental hazards
70
2 other glands of integumentary system
-mammary glands
-ceruminous glands
71
Ceruminous glands
Modified sweat glands that produce cerumen or earwax to prevent foreign particles from reaching the eardrum
72
Nails
Protect fingers and toes made from dead cells packed with keratin
73
Nail body
Visible portion of the nail
74
Nail bed
Epidermal portion under the nail body
75
Free edge
Tip of the nail that extends past the nail bed
76
Nail grooves
Part of the edges that go into the skin
77
Nail folds
The parts of skin that ‘fold’ over the nail depressions
78
Hyponychium
An area of thickened stratum corneum, tip of finger under the nail free edge
79
Eponychium
Cuticle
80
Lunula
Near the root blood vessels are obscured producing a pale moon shape
81
Nail root
Where nail production takes place at fold near the bone not visible from the surface
82
Repair of the skin post trauma
-bleeding, swelling and pain occurs
- mast cells trigger inflammatory response
-a scab (dried blood clot) stabilizes and protects the area
- macrophages clean the area
- fibroblasts and endothelial divide producing granulation tissue
83
Inflammation phase
Phase1
- immediately after injury
-bleeding, swelling and pain occurs
- mast cells trigger inflammatory response
84
Migration phase
Phase 2
- hours after injury
-a scab (dried blood clot) stabilizes and protects the area
- macrophages clean the area
85
Proliferation phase
Phase 3
-week after injury
- phagocytic activity has ended
- fibroblasts and endothelial divide producing granulation tissue
86
Scarring phase
Phase 4
-several weeks after injury
-scab has been completely shed/ clot dissolved
- non cellular scar tissue is produced and number of capillaries declines
- shallow depression marks the site or raised keloid may form
87
Effects of aging on skin
- epidermis thins
- # of dendritic cells decrease
- vit d production declines
- melanocyte and glandular activity decline
- blood supply to dermis is reduced
- functional hair follicles decline
- dermis thins and elastic fiber network shrinks
- sex-specific hair and body fat distribution fades
- repair rate slows
