Skin Structure and Function

Question 1

The “mortar” of epidermis layers

Answer 1

Lipid seal

Question 2

Hemi-desmosomes

Answer 2

Anchor the basal cells to the lamina lucida of the basement membrane

Question 3

Desmosomes

Answer 3

The cellular attachments between the upper layers of skin, keratinocytes

Question 4

Melanocyte

Answer 4

Produces pigment granules which are transferred to the adjacent keratinocytes

Question 5

Epidermal Melanin Unit

Answer 5

Melanocyte and adjacent keratinocytes

Question 6

Location of Melanocytes

Answer 6

At the basal layer of the living epidermis

Question 7

Vitiligo

Answer 7

Autoimmune attack of the melanocytes

Question 8

Freeze Branding

Answer 8

Damage melanocytes so that the hair grows back white

Question 9

Dermatophilosis

Answer 9

Reduced immunity from malnutrition and tick infestation allowing severe skin infections

Question 10

Corpuscle

Answer 10

Like a receptor

Question 11

Location of motor nerves

Answer 11

Ventral Horn

Question 12

Location of sensory nerves

Answer 12

Dorsal Horn

Question 13

What forms the bulk of dermis thickness

Answer 13

Collagen

Question 14

What produces collagen

Answer 14

Fibroblasts

Question 15

Orientation of elastic fibers in the superficial dermis

Answer 15

Vertical

Question 16

Orientation of elastic fibers in the deep dermis

Answer 16

Horizontal

Question 17

Ehlers-Danlos Syndrome

Answer 17

Skin hyperextensibility caused by collagen defects

Question 18

Blood supply to the skin

Answer 18

Superficial, mid, and deep vascular plexus

Question 19

Vasculitis

Answer 19

Damaged and inflamed blood supply to skin which causes devitalization

Question 20

Perivascular

Answer 20

AROUND the blood vessels

Question 21

Epitrichial

Answer 21

Apocrine, produces sweat within the hair follicle

Question 22

Atrichial

Answer 22

Eccrine, produced sweat directly to the skin surface

Question 23

Sebocyte

Answer 23

Cell of the sebaceous gland. Lipid synthesis

Question 24

Sebaceous Adentitis

Answer 24

Glands destroyed by inflammation

Question 25

Dermal Papilla

Answer 25

mesenchymal cells

Question 26

Hair matrix

Answer 26

Epidermal stem cells divide to produce hair shaft and root sheaths

Question 27

Hair shaft

Answer 27

Dead keratinocytes packed together

Question 28

Outer root sheath

Answer 28

Continuous with the lining of the hair follicle infundibulum and the epidermis of the skin surface

Question 29

Inner root sheath

Answer 29

Breaks down at the level of the follicular isthmus, allowing the hair shaft to separate from the infundibular lining and fall free from the skin

Question 30

Telogen Phase of follicle growth

Answer 30

The resting phase. Long phase. This is after the inferior portion undergoes apoptosis and the hair is loosely held in the follicle

Question 31

Anagen Phase of follicle growth

Answer 31

Active growth with hair held tightly in follicle. Short phase.

Question 32

Catagen Phase of follicle growth

Answer 32

Short phase characterized by the involution/apoptosis of the inferior portion

Question 33

Dynamic hair growing cycle

Answer 33

Allows for different coat colors each season. Dogs grow hair in a mosaic pattern which rodents replace hair in a wave pattern from head to tail

Question 34

Exogen

Answer 34

Hair is lost independently of follicle cycle

Question 35

Simple Follicle Anatomy

Answer 35

One hair in one follicle. Horses, humans, and ruminants

Question 36

Complex Follicle Anatomy

Answer 36

Multiple hairs in one follicle. Cats and Dogs

Question 37

Primary Hairs

Answer 37

Guard hairs, wide diameter

Question 38

Secondary Hairs

Answer 38

Fine undercoat hairs

Question 39

Dermatophytosis

Answer 39

Fungal spores on hair. Ringworm

Question 40

Demodicosis

Answer 40

Mites

Question 41

Miniaturization

Answer 41

The hairs are present, they are cycling, but very thin. Male pattern baldness

Question 42

Hyperadrenocorticism

Answer 42

Hair anagen cycle arrested during Cushing's

Question 43

Sphynx Cat

Answer 43

Congenital alopecia associated with mutated KRT71

Question 44

Curly coated retriever follicular dysplasia

Answer 44

CCR FD causes misshapen hair shaft. They get frizzy saddle side.

Question 45

Shark skin

Answer 45

Spiky projections oriented caudally