Skin Flashcards

Question

Stratum granulosum

Answer 1

thin layer keratinocytes still retain nucleus and basophilic keratohyalin granules and membrane-coating granules not uniform in distribution may not be present in thin skin

Answer 2

``` clear layer/lightly stained thin layer flattened dead cells no nuclei or organelles that contain densely packed keratin filaments only found in thick, hairless skin ```

Answer 3

outermost layer keratinized flattened cells (squamous) dead cells filled w/keratin filaments embedded in an amorphous matrix outermost stratum corneum is sloughed off in normal process of wear and tear

Answer 4

elastic, desquamates (ex: skin)

Answer 5

``` more sulfur than soft keratin less elastic more permanent resistant to degradation does not desquamate (ex: nails, horns, hooves) ```

Answer 6

Dermal layer subepithelial loose CT contains thin collagen and elastic fibers in loose networks

Answer 7

dermal layer dense CT thick type I collagen fibers packaged into large bundles assoc. w/thick elastic fibers contains epidermally derived hair, sweat, and sebaceous glands thick in horse and cow thin in carnivores

Answer 8

neoplasia of cells in stratum spinosum Accounts for 15% of cutaneous tumors in the cat and 5% of those in the dog Usually found in unpigmented or lightly pigmented skin

Answer 9

Melanocytic tumor represents 4-7% of all canine neoplasms most common malignant tumor of canine oral cavity and digits Early recognition can lead to more successful attempts at removal and ID of grade/stage of cancer can metastasize to any area of body, esp. lymph nodes and lungs cats seem much less susceptible to melanoma tumors than dogs

Answer 10

dead produced by living keratinocytes at base of hair (hair bulb) pigmentation comes from melanocytes

Answer 11

sac from which a hair grows and into which sebaceous glands open Function - insulation, camouflage, sex recognition, social purposes Types: single and compound

Answer 12

=simple hair follicle one hair emerges from a single open found in horse, cattle, pig, sheep face, ear, distal portion of limbs

Answer 13

several hairs emerge from a single opening cat, dog, sheep (wool growing areas) consists of a long principle/guard hair and 7-20 soft, smaller, auxiliary (wool) hairs, (undercoat)

Answer 14

Hair bulb Hair shaft Hair Sheath Arrector pili muscle

Answer 15

=hair root and dermal papilla located at the base of hair follicle comprised of germinal matrix cells - give rise to layers of hair and to internal and external epithelial root sheath dermal papilla: forms center base of hair bulb - sends chemical signals that induce germinal matrix to proliferate, plays an important role in hair growth hair root: embedded in a hair follicle. contains epithelial cells that actively divide about dermal papilla. Produces 5 cell layers (hair shaft forms inner 3 layers and hair sheath forms outer 2)

Answer 16

non-growing portion of a hair that protrudes from skin consists of inner 3 layers of hair root characteristics are species specific Cuticle: hard, thin, outermost layer of hair. comprised of a single layer of flat, keratinized cells w/overlapping edges (interdigitates w/cuticle of internal epithelial root sheath) Cortex: consists of compact, dead, keratinized cells - form the bulk of hair shaft - pigment may be present Medulla - central region of shaft - may be absent in some hairs - comprised of flattened cells separated by numerous air spaces

Answer 17

outer 2 layers from hair root inner epithelial root sheath - forms from periphery of germinal matrix - surrounds hair root and ends somewhere around the point of input of sebaceous glands external epithelial root sheath - adjacent to internal root sheath - similar in structure and continuous with stratum germinativum - upper part keratinized, lower part not

Answer 18

``` smooth muscle origin at epidermal/dermal junction inserts onto the outside of the follicle contraction --> erection of hair (piloerection) response to cold, anger, fear innervated by the sympathetic nervous system most evolved in furry animals increases insulation against heat loss ```

Answer 19

``` =sudoriferous glands simple, coiled tubular glands hollow or more or less circular walls composed of low cuboidal epithelium Types: eccrine and apocrine ```

Answer 20

``` small widely distributed produce a watery secretion mainly a mechanism for cooling restricted to foot pads of carnivores, frog of ungulates, and nasolabial region of ruminants and swine ```

Answer 21

larger cuboidal epithelium produce oily and foamy secretions most common in the grown, axilla and scrotum of dogs and cats most numerous and extensive in horses most common type found in domestic animals pheromones are produced and emitted by these

Answer 22

simple, often branched acinar glands open into a hair follicle about halfway up the shaft secrete sebum = lysed cells and accumulated lipids containing precursors of vitamin D; gives hair it's sheen and acts as a lubricant for skin and hair

Skin Flashcards

(46 cards)