Integument

Question 1

Types of cells in the epidermis?

Answer 1

Keratinocytes
Non keratinocytes
1. Langerhans
2. Merkels
3. Melanocytes
4. Intraepithelial lymphocytes

Question 2

Papillary vs Reticular layer

Answer 2

Papillary:
- type 1 & 3 collagen
- loose CT
- macrophages and mast cells

Reticular:
- type 1 collagen
- deeper layer
- dense irregular CT
- elastic fibers

Question 3

Apocrine sweat gland

Answer 3

• apical budding
• help from myoepithelial cells

Functions as COMMUNICATION

Question 4

Mesocrine sweat gland

Answer 4

• Exocytosis
• Functions for THERMOREGULATION and ELECTROLYTE BALANCE

-secretes fluid when body temp rises

Question 5

What are the layers of skin from deep to most superficial?

Answer 5

Stratum basale
spinosum
granulosa
Stratum lucidum
Stratum corneum

Question 6

What are the steps to the hair cycle?

Answer 6

Anagen- hair bulb mitotically active
Catagen- metabolic slows, follicle moves to surface
Telogen- grow stops, base of bulb at sebaceous canal, new hair underneath

Question 7

What are the steps of the hair cycle controlled by?

Answer 7

• temp
• hormones
• daylight
• nutrition

Question 8

What are the function of sebaceous glands?

Answer 8

Antibacterial, waterproof

Question 9

Arrector pili

Answer 9

smooth muscle attached to primary cells

Functions as INSULATION

Ex: goosebumps

Question 10

Layers of the hoof wall

Answer 10

1. Stratum externa- perioplic epidermis
2. Stratum medium- main support, coronary groove with tubular and intertubular horns
3. Stratum interna (lamellatum)- insensitive lamellae

Question 11

Underlying dermis in hoofs

Answer 11

corium, sensitive laminae

Question 12

What part of the dermis carries blood to the cells of the hair?

Answer 12

Dermal papilla

Question 13

Characteristics of stratum basale

Answer 13

• most active (mitotic), deepest layer of epidermis

-single cuboidal

-attached to basal lamina w hemidesmosomes

-keratinocytes, melanocytes, langerhans, merkels

Question 14

What layer of the epidermis has many tonofilaments and desmosomes?

Answer 14

Stratum spinosum

Question 15

Stratum Corneum

Answer 15

• most superficial, thick layers of keratin

-dead cells, horny cells

Question 16

What layer of the epidermis has keratohylan and lamellar granules?

Answer 16

Stratum granulosa

Question 17

Merkels

Answer 17

• A non keratinocyte
• in stratum basale of thick skin

Functions as a MECHANORECEPTOR for sensation

Question 18

Langehans

Answer 18

1. a non keratinocyte
2. in the basale and spinosum layer
3. intra epidermal macrophages
4. from bone marrow monocytes

Functions as IMMUNITY (T cells, tolerance)

Question 19

Nociceptors

Answer 19

free nerve ending goes to stratum granulosa

Detects pain, itch, temp

Question 20

What layer of the epidermis has eleidin?

Answer 20

Stratum Lucidum

Question 21

Primary vs Secondary hair follicle

Answer 21

Primary:
1. larger diameter
2. deep in dermis
3. sebaceous glands, arrector pili, sweat glands

Secondary:
1. smaller
2. near surface
3. no sweat glands or arrector pili

Question 22

Compound hair follicle

Answer 22

many hair follicles, 1 primary and several secondary

Ex: carnivores

Question 23

Components of hair

Answer 23

Medulla- loose cuboidal areas in middle of hair follicle

Cortex: dense keratin (pale yellowish area)

Cuticle: single layer, flat keratin cells

Question 24

Ex of special apocrine glands

Answer 24

1. Mammary gland
2. Moll
3. Anal sac
4. Ceruminous (ear wax)

Question 25

Ex of special sebaceous glands

Answer 25

1. Tarsal (meibomian gland- eyelid)
2. Uropygial (preen gland in bird)
3. Horn gland
4. Supracaudal

Question 26

Sinus hairs (whiskers)

Answer 26

Tactile, large single follicle

Attached to skeletal muscle, voluntary movement

Question 27

Encapsulated nerve endings?

Answer 27

1. Meissners- light pressure/touch
2. Pacinian Corpuscle- deep pressure
3. Ruffini- stretch

Question 28

Thick vs thin skin

Answer 28

Thick:
- thick epidermis
- hairless
- merocrine sweat glands
Ex: paw pads, nose

Thin:
- thin epidermis
- has hair and arrector pili
- sebaceous and sweat glands

Question 29

3 components of the integument system

Answer 29

1. Epidermis- from ectoderm
2. Dermis- from mesoderm
3. Hypodermis (subcutis)

Question 30

Characteristics of the hypodermis

Answer 30

• subcutis
• loose CT, rich in adipocytes= panniculus adiposus