Ch 5

Question 1

Integumentary System definition

Answer 1

The skin and its accessory structures

Question 2

Layers

Answer 2

Epidermis, Dermis, Hypodermis (fat layer)

Question 3

Melanocytes

Answer 3

produces melanin, brown/black pigment which absorbs UV light and is the primary skin pigment.
approx. 8% of Epidermal cells

Question 4

Epidermis

Answer 4

made up of keratinized stratified squamous epithelium (avascular no bleeding)

Question 5

Keratinocytes

Answer 5

produce the water-insoluble protein keratin which hardens structures.
approx. 90% of Epidermal cells

Question 6

Langerhans cells

Answer 6

produced in the bone marrow - travels to skin
helps provide immunity to the epidermis

Question 7

Merkel cell (disc)

Answer 7

nerve ending for touch (tactile receptors)

Question 8

Dermis

Answer 8

mostly connective tissue containing collagen and elastin fibers, few cells

Question 9

Papillary region

Answer 9

superficial portion

Question 10

Dermal Papillae

Answer 10

tiny projections into the epidermis which increases the surface area of the Stratum Basal

Question 11

Epidermal Ridges

Answer 11

dermatoglphs = fingerprints assoc. with underlining papillae.

Question 12

Meissner Corpuscles

Answer 12

tactile receptors located at the apex of the Dermal Papillae

Question 13

Reticular Region

Answer 13

deepest and largest portion
contain irregular c.t

Question 14

Deep Wound Healing

Answer 14

Damage effects the Dermis

Question 14

Hypodermis

Answer 14

composed of adipose and areolar c.t
stores fat
contains vessels and nerves and supply the skin

Question 15

Superficial healing

Answer 15

only when the epidermis is damaged; cells surrounding the wound enlarge and migrate to fill the gap created by the injury
migration of cells happens and mitosis in Stratum Basal is stimulated more cells are reproduced to make up for the dead cells

Question 16

Inflammatory Phase

Answer 16

clot forms overwound
local vasodilation, leukocytes (infection) and fibroblasts (rebuild tissue) move into the damaged area

Question 17

Migrating Phase

Answer 17

scab forms
epithelial tissue migrates beneath the scab to bridge the wound.
granulation (scar) tissue begins to be laid down beneath the scab
vessels begin to grow

Question 18

Proliferative Phase

Answer 18

epithelial tissue begins to mature
collagen fibers continue to be laid down randomly

Question 19

Maturation Phase

Answer 19

scab falls after epidermis is repaired
circulation is restored
fibroblasts dec in number.

Question 20

Fibrosis

Answer 20

scar tissue formation.

Question 21

Keloid

Answer 21

uncontrolled fibrosis

Question 22

Thermoregulation

Answer 22

The average temp is 98.6 F; 37 C

Question 23

Ambient temp is elevated

Answer 23

Perspiration inc, heat is lost by evaporation.
Smooth muscle in dermal vessels relax there diameter to inc. More bl can now enter these vessels.

Question 24

Ambient temp decreases

Answer 24

Sweat gland activity decreases. Body conserves heat.
Smooth muscle in dermal vessels constricts conserving heat.