Integumentary System

Question 1

Major functions (4)

Answer 1

• physical/immunological protection
• thermoregulation
• sensation
  -metabolic function ( vit D, stores fat)

Question 2

Tissue Composition

Answer 2

1- epithelium
2- connective tissue
3- smooth muscle
4- nerve

Question 3

Epithelium

Answer 3

covers surface, forms boundary

Question 4

Connective tissue

Answer 4

supports epithelium- strength/resilant

Question 5

Smooth muscle

Answer 5

controls blood vessel diameter (blushing), hair position (hair up/down)

Question 6

Nerve

Answer 6

controls smooth muscle
generates sensation (tactile/temp etc)
stims exocrine glands

Question 7

Structure of skin

Answer 7

Epidermis (TOP)
dermis- nerves, muscle, connective tissue
hypodermis - fat reserves (BOTTOM)

Question 8

How to dermis and epidermis connect?

Answer 8

Epidermal ride + dermal papilla interlock (peak-and-valley) - RESIST shearing stress

Question 9

Structure of epidermis (7)

Answer 9

• Stratum Corneum (superficial)
  -stratum lucidum
  -stratum granulosum
  -stratum spinosum
• stratum germinativum
• dermal papilla
  -dermis

Question 10

Stratum Germinativum

Answer 10

aka stratum basale (large basal cells)
-attached to basil lamina
- stem cells divide –> new keratinocytes
-

Question 11

Stratum Spinosum

Answer 11

Made up of Keratinocytes –> contain tonofilaments (protein)
desmosomes (space in between) - attach keratinocytes together
last layer keratinocytes can divide

Question 12

Stratum Granulosum

Answer 12

production of keratohyalin and keratin
secrete lipids - fill spaces bt/wn kertinocytes (water- repellent )

Question 13

Stratum Lucidum

Answer 13

CLEAR LAYER
large amounts of keratin & thick plasma membranes
ONLY FOUND in volar skin

Question 14

Stratum Corneum

Answer 14

layers of dead cell - continous shed
water repellant barrier
protect against abrasion

Question 15

Thick vs think skin

Answer 15

Thin skin - thin stratum corneum
- less clear layers
- dermal papillae/epidermal ridges less developed

Question 16

Dermis - Papillary layer

Answer 16

-thin layer
-areolar connective tissue
- increase area of contact w epidermis
-has nerve endings

Question 17

Dermis- Reticular layer

Answer 17

• thick layer
• dense, irregular c. tissue
• elastic fibres

Question 18

lines of cleavage

Answer 18

differently aligned collagen fiber bundles in the body
- align along lines of tension

Question 19

Hypodermis structure

Answer 19

superficial fascia
stabalizes position of skin
loose connective tissue- stores fat

Question 20

merkel cells

Answer 20

specialized skin cell
least common type
located in basal layer (stratum germinativum) - touch sensation

Question 21

langerhans cells

Answer 21

originate in bone marrow - migrate to epidermis
phagocyte - immune response

Question 22

Melanocyte

Answer 22

in between keratinocyte -produced melanin

Question 23

Skin colour

Answer 23

blood supply to dermis
oxygenated hemoglobin- pink skin hue
deoxygenated hemoglobin- blue skin hue
blood vessel dilation (increase blood flow)- redness

Question 24

three pigments

Answer 24

Carotene (yellow/orange)
pheomelanin (red/yellow)
melanin (brown/black)

Question 25

melanin

Answer 25

in darker skin- melanosomes are lager, keratinocytes persist to more superficial layers if skin (pigmentation)

Question 26

Exocrine glands

Answer 26

1) sweat - merocrine (eccerine) secretion --> exocytosis no cell death 2) sebaceous glands - secrete oily lipid --> coats hair and skin surface -holocrine secretion --> secretory product invades cell which burst for product release CELL DEATH)

Question 27

Sweat glands (2)

Answer 27

simple coiled tube glands 1) apocrine sweat glands - odiferous sweat --> Merocrine mechanism, specific to body region, secrete water, electrolytes, lipids, proteins (emotional stress/arousal) 2) Merocrine glands- normal sweat glands --> widespread, regulate body temp, secrete water/electolytes

Question 28

Special apocrine sweat glands (2)

Answer 28

1) Ceruminous glands modified sweat glands secrete waxy cerumen (ear wax) via merocrine secretion 2) Mammary glands specialized for milk production apocrine secretion--> product released with shedding + no cell death regulated by sexual/pituitary hormones

Question 29

hair

Answer 29

covers all body surfaces except volar skin uv protection/ thermal insulation touch sensation/particle filtration

Question 30

anatomy of a hair follicle

Answer 30

LOOK AT DIAGRAM

Question 31

Types of hair (3)

Answer 31

1) Vellus hair - peach fuzz 2) Intermediate hairs- hairs of limbs, distribution based on sex hormones 3) terminal hairs - more pigmented, sclap, eyebrows etc

Question 32

Hair growth cycle

Answer 32

Scalp- 2-6 years, rest = 3 months (no growth)