Integument 2

Question 1

where is hair produced

Answer 1

by hair follicles embedded in the dermis

Question 2

what is the function of hair

Answer 2

1. mechanical protection
2. thermoregulation
3. snesory perception

Question 3

what does a simple hair follicle contain

Answer 3

cuticle, cortex and medulla

Question 4

what are these structures

Answer 4

Question 5

where does the hair shaft project

Answer 5

above the surface of the skin epidermis

Question 6

what is the hair follicle embedded in

Answer 6

the dermis and hypodermis

Question 7

where is the hair anchored

Answer 7

within the follicle

Question 8

what does the root consist of

Answer 8

consists of the hair and surrounding root sheaths

Question 9

what does the bulb consist of

Answer 9

the dermal papilla and hair matrix cells (stem cells)

Question 10

where do cells become keratinized

Answer 10

in the keratogenous zone

Question 11

what occurs in the hair bulb and the keratogenous zone

Answer 11

matrix cells are mitotically active (cylcic activity)

actively dependant on dermal papilla

migrating matrix cells pass through keratogenous zone (hard keratin) –> differentiate to form hair and internal root sheath

Question 12

what are the phases of the hair cycle

Answer 12

1. terminal follicle (anagen)
2. regressive (catagen)
3. quiescent (telogen)
4. renewed growth –> shedding –> new (early anagen)

Question 13

what is the hair cycle controlled by

Answer 13

1. photoperiod
2. ambient temperature
3. health
4. genetics
5. nutrition
6. hormones
7. local factors that directly influence the growth of hair follicles

Question 14

how are compound hair follicles formed

Answer 14

1. at birth –> simple hair follicle (gaurd hair)
2. development of secondary follicles (undercoat)
3. compound hair follicle –> adult

Question 15

what are the features of sinus or tactile hair

Answer 15

1. limited facial distribution
2. extremely large
3. specialized for tactile sense (blood filled sinus, skeletal muscle, innervated)

Question 16

what is the function of sebaceous glands

Answer 16

1. waterproofing
2. suppleness
3. spread sweat

Question 17

what do sebaceous glands secrete

Answer 17

sebum

Question 18

what are the features of the secretory portion

Answer 18

pale staining

flask shape

holocrine secretion

Question 19

what are the features of excretory duct

Answer 19

empties into hair follicle

Question 20

what is sweat

Answer 20

ultra-filtrate of blood plasma

Question 21

what are the functions of sweat

Answer 21

1. thermoregulation
2. excretion
3. scent signalling

Question 22

what are the features of the secretory portion of sweat glands

Answer 22

1. simple cuboidal epithelium
2. myoepithelial or “basket” cells surround aid secretion

Question 23

what is the difference between apocrine and eccrine sweat glands

Answer 23

apocrine = empty into hair follicle

eccrine = empty directly onto skin surface via sweat pore

Question 24

how many layers of epithelium does the excretory duct on a sweat gland contain

Answer 24

2 layers of cuboidal epithelium

Question 25

what type of glands are mammary glands

Answer 25

modified sweat glands

Question 26

which glands are which

Answer 26

sweat gland left

sebaceous right

Question 27

what are specialized skin glands

Answer 27

localized accumulations of sweat or sebaceous glands

ex. supracaudal (or tail) gland in dog –> concentration of sebaceous glands on dorsum of tail

Question 28

what are claws, hoofs and horns

Answer 28

highly specialized forms of derivatives of the skin

Question 29

what are the features of claws, hoof and horn

Answer 29

retain structural organization of epidermal, dermal and subcutis equivalent layers –> modified form

Question 30

identify the numbers

Answer 30

thin hairy skin

4. epidermis
5. sebaceous gland
6. dense irregular connective tissue
7. hair

Question 31

what structures can be seen

Answer 31

hair matrix cells

dark pigmentation is melanocytes