Chapter 5 : integumentary Flashcards
1
Q
epidermis
A
keratinized(hard), stratified squamous epithelium made of four distinct cell types and four-five layers
2
Q
dermis
A
strong, flexible connective tissue, supplied with nerves, blood vessels, and lymphatic
3
Q
the skin functions
A
protects us from bacteria, external agents, and water and heat loss
4
Q
skin layers
A
- two layers, the outer epidermis and underlying dermis
- the dermis which makes up the bulk of the skin is vascularized, the epidermis is not
5
Q
hypodermis
A
- superficial fascia
- mostly made of adipose (fat) tissue
- function- fat storage- insulation - shock absorption - anchors your skin to muscle underneath
6
Q
arrector pilli
A
bundle of smooth muscles, associated with each hair follicle
- pulls the hair upright
7
Q
cells of epidermis- keratinocytes
A
these produce keratin, gives skin its protective properties
- dead by the time they are pushed to the surface; replaced by mitosis
- replace entire epidermis every 25-45 days
8
Q
cells of epidermis- melanocytes
A
these make pigment melanin, found deep in epidermis
9
Q
epidermal dendritic cells
A
- langerhans cells
- arise from the bone marrow, migrate to the epidermis to ingest foreign substances and activate the immune system
10
Q
cells of epidermis- tactile (Merkel cells)
A
found at the epidermal/dermal junction; associated with a sensory hair ending and acts as a sensory receptor for touch
11
Q
layer of epidermis- Stratum basale
A
- basal layer
- deepest epidermal layer, attached to the dermis underneath
- mostly one layer of stem cells thick; produces youngest keratinocytes
- also 10-25% of cells there are melanocytes
12
Q
layer of epidermis-stratum spinosum
A
- prikly layer
- several layers thick, contain intermediate filaments, attached to desmosomes
- look like prickly balls
- allow tissue to stretch without tearing apart
13
Q
layer of epidermis- stratum granulosum
A
- granular layer
- 3-5 cell layers where keratinization(cells filled with keratin)begins
- contains 2 types of granules one that helps begin keratin formation and the other that forms a water resistant coat
14
Q
layer of epidermis- stratum Lucidum
A
- clear layer
- 2-3 rows of flat dead keratinocytes, visible only in thick skin
- only found in extra layers-bottom of foot
15
Q
layer of epidermis-stratum corneum
A
- horny layer
- outermost layer, 20-30 cell layers thick
- protects skin against abrasion & penetration
- avg. person sheds 18 kg (40Lbs) of skin in a lifetime
16
Q
layer of dermis- Papillary layer
A
aerolar connective tissue; forms a loosely woven mat full of small blood vessels
-dermal papillae- peg-like projections that may contain capillary loops, nerve endings & touch receptors and underly the sking rideges of our fingerprints
17
Q
layer of dermis- reticular layer
A
- coarse, irregularly arranged in dense fibrous connective tissue
- made up of collagen fibers with pockets of adipose tissue
- collagen gives skin strength and keeps it hydrated, while elastic fibers make skin stretchy
18
Q
3 substances that determine basic skin color
A
- melanin
- carotene
- hemoglobin
19
Q
bluish skin color indicates..
A
not enough oxyegen
20
Q
redness of skin indicates..
A
emotional , indication of allergy too
21
Q
pallor (pale) skin indicates
A
-emotional stress, indicates anemia or low blood pressure
22
Q
jaundice(yellow) indicates..
A
liver disorder
23
Q
bronzing of skin indicates….
A
Addison’s disease
-not enough steroid hormones, or pituatary gland tumor
24
Q
Eccrine sweat glands
A
- Eccrine(meocrine) glands
-more numerous on palms, feet and forehead
Functions:
-coiled tubular gland
-sweat- hypotonic filtrate of blood released through sweat glands by exocytosis -higher water to particle ratio - controlled by the autonomic nervous system-prevent over heating
25
Apocrine sweat glands
-Apocrine sweat glands
-there are only about 2K of them mostly in axillary(armpit), anogenital regions
-larger than eccrine, deeper in dermis, ducts empty into hair follicles
-produce sweat: fatty substances & proteins
-source of BO when bacteria on skin decomposes these organic molecules
Why? sexual or puberty
26
Sweat gland- Ceruminous (wax glands)
modified apocrine glands found in the lining of secretion mixes with sebum from oil glands to form cerumen, AKA external ear canal-ear wax
27
sweat gland- mammary gland
specialized sweat glands that secrete milk
28
sebaceous oil glands
- branched alveolar glands found everywhere except palms and soles
1. secrete oily substace, sebum
2. most sebaceous glands develop from hair follicles and serve to soften and lubricated hair & skin. Slow water loss from skin , kill bacteria
3. When blocked= pimples ; inflammation= acne
4. too much sebum= seborrhea (cradle pap)
29
main substance that makes up hair
hairs or pilli are produced by hair follicles and are largely dead keratinized cells
30
3 layers that make up hair
medulla, cortex, cuticle
31
medulla
- inner layer of hair
| - large cells and air spaces, absent in fine hairs
32
mental cortex
- middle mental cortex of hair
| - made of several layers of flattened skin
33
cuticle
- the outer layer of hair
| - formed of overlapping layers of shingles
34
hirsutism
- excessive hairiness in women
| - caused by adrenal gland or ovarian tumor
35
alopecia
- hair thinning & baldness
| - after 40 , hairs may not be replaced as often as they are shed
36
true male pattern baldness
- genetic, sex influenced
- due to delayed action gene switched on at adulthood that changes responses of follicles to a testosterone metabolite
- this causes growth cycles to become short and hairs never emerge from their follicles before shedding
37
alopecia areata
immune system attacks the follicles and the hair falls out
38
yellow tinged nails...
respiratory or thyroid problem
39
thickening nails
fungal infection
40
outward concavity in nails
iron deficiency
41
horizontal line in nails
malnutrition
42
chemical barriers
skin secretions and melanin production
a. acid mantle-ph -retards bacteria growth
b. dermicidin in sweat and bactericidal substances in sebum
c. cathelicidins- released by wounded skin, to help strep H infections
e. melanin- chemical pigment shield against UV
43
physical/mechanical barriers
epidermis is water resistant and blocks most water-soluble aubstances
a. however some things do penetrate the skin in small amounts including: O2, CO2, VIT(adek), poisin ivy, organis solvents(acetone & paint thinner), salts(lead & mercury), drug agents
44
biological barriers
dendritic cells in epidermis, macroophages in dermis, and DNA
45
dendretic cells
these are present foreign substances to WBCs
46
dermal macrophages
also act as antigen presenters
47
DNA as bio barrier
electrons absorb UV radiation and transfer it to the atomic nuclei which heat up and vibrate, then transferring heat to water molecules
-can actually absorb UV and convert into heat
48
how does body protect body from extreme temperatures?
-too high: nervous system stimulates dermal blood vessels to dilate and sweat glands start secreting.
On hot days, we can sweat 12L (3 gallons)-sends more blood to skin area
-too low: dermal blood vessls constrict, causing warm blood to bypass the skin.
This allows skin to be same temp as outside. Sends blood to core of the body.
49
what types of cutaneous sensations are there?
cutaneous sensory receptors respond to stimuli outside the body (sensors pressure)
1. light touch- Meissner's corpuscles and tactile discs
2. bumps or deep pressure contact-Pacininian corpuscles
3. respond to light manipulation of the hair- hair follicle receptors
4. painful stimuli- free nerve endings
50
What are some metabolic functions of the skin?
1. Synthesizes Vit D precursor in response to sunlight
2. Disarm cancer causing chemicals
3. Convert harmless chemicals into carcinogens
4. Activate some steroid hormones ex. transform cortisone to hydrocortisone (anti-inflammatory)
51
How does the skin act like a blood reservoir for the body?
1. Dermal vascular supply can hold about 5% of body's total blood volume
2. When other body organs need more blood, the nervous system constricts the dermal blood vessls, this constriction shunts more blood into general circulation, making it available to the muscles and other body organs
52
shunt
push or pull (a train or part of a train) from the main line to a siding or from one track to another.
53
Basal cell carcinoma
- 80% of skin cancers
| - least serious, found on face
54
Squamous cell carcinoma
grows quickly on head and hands, can be removed surgically or by radiation therapy
- remove before they metastisize
55
Melanoma
- highly metastic, resistant to chemotherapy, get them pre-existing moles
- treatment: Before-surgury or After- immunotherapy
56
Problems for burn victims
-loss of fluids, extra calories to help recover, invasion of the destroyed area by bacteria or fungi(serious infections)
57
first degree burn
any epidermis of skin is damaged, sunburn
58
second degree burn
both epidermis and upper region of dermis, marked by blistering, heal-time:3-4 weeks
59
third degree burn
involves the entire thickness of the skin, you will need skin graft
60
What germ layers do the epidermis,dermis(hypodermis) develop from?
The epidermis develops from the ectoderm and the dermis and hypodermis from the mesoderm
