skin, hair, special sense

Question 1

functions of skin

Answer 1

protection, temperature regulation, secretion of various substances

Question 2

dermatitis

Answer 2

inflammation of the skin

Question 3

seborrhea

Answer 3

abnormal secretions from the oil glands of the skin, often due to a defect in keratinization

seborrhea sicca (dry)
seborrhea oleosa (moist)

Question 4

epidermis

Answer 4

made up of stratified squamous epithelial cells in 5 superficial layers, contains keratin

Question 5

epithelial tissue covers where?

Answer 5

the interior + exterior surfaces of the body, lines body cavities, and forms glands

Question 6

all epithelial tissues share what 3 common features

Answer 6

they are made up entirely of cells

they do not contain blood vessels and obtain nourishment from blood vessels in the tissues beneath them

at least some are capable of reproducing and repairing damage

Question 7

how does the epidermis reproduce

Answer 7

the deepest layer of cells reproduce pushing daughter cells to the surface which gradually die and assume a flattened shape

Question 8

skin color

Answer 8

pigment cells which have pigment granules called melanin that gives skin its color - these are located in the deep layer of the epidermis

Question 9

how does melanin disperse?

Answer 9

via the melanocyte stimulating hormone (MSH)

Question 10

in reptiles, fish, and amphibians, MHS permits what?

Answer 10

rapid changing of skin color

Question 11

what is the absence of pigment

Answer 11

albinism

Question 12

dermis

Answer 12

the deeper tissue layer that contains vessels and nerves

Question 13

what does the dermis contain?

Answer 13

arteries, veins, capillaries, and glands

nerve fibers that supply the hair follicles + sweat glands

receptors for touch, heat, cold, pain

Question 14

what does the dermis contain?

Answer 14

arteries, veins, capillaries, and glands

nerve fibers that supply the hair follicles + sweat glands

receptors for touch, heat, cold, pain

Question 15

hypodermis

Answer 15

separates the dermis from underlying structures such as bone and deep fascia

(AKA the superficial fascia or SUBCUTANEOUS TISSUE)

Question 16

what does the hypodermis permit?

Answer 16

movement of the skin without tearing and the existence of fat btwn the skin and deeper structures for insulation

Question 17

hair

Answer 17

hair follicles develop first as a thickening and then as an in-growth of the epidermis

hair papilla is located at the base of the follicle in the dermis

an internal sheath covers the root of the hair and is continuous with the papilla, the external sheath is continuous with the epidermis and gives rise to the sebaceous glands

Question 18

how does hair grow?

Answer 18

it is formed from the epithelial cells covering the papilla - as the cells grow, multiply, and keratinize; they push the hair up from the follicle