Integumentary Flashcards
what is pathogenesis
understanding on lesions develop
what is pathophysiology
understanding how lesions result in clinical signs
what is the most frequently biopsied organ
skin
what are the layers of the epidermis
stratum corneum
stratum granulosum
stratum spinosum
stratum basale
what are the layers of the epidermis composed of
keratinocytes
which layer of the epidermis is composed on corneocytes
stratum corneum
what are corneocytes
keratinized cells
what is the purpose of the stratum corneum
protective outer barrier
what is the stratum granulosum made of
keratohylin granules
what layer of the epidermis is polyhedral-shaped cells with desmosomal attachments which are visible histologically as intercellular bridges
stratum spinosum
what layer of the epidermis containing single layer of cuboidal cells resting on the basement membrane basal cells with specialized cells
stratum basale
what cells make up the layers of epidermis
keratinocytes
what separates the epidermis and dermis
basement membrane zone
what provides intercellular adhesion between keratinocytes
desmosomes
what provides attachment of the epidermis to the basement membrane
hemidesmosomes
what layer of the skin is composed of collagen and elastin fibers embedded in glycosaminoglycan ground substance
dermis
what is the purpose of the dermis
provides support for epidermis, adnexa, vessels, and nerves
true or false:
the dermis has a lot of inflammatory cells present under normal conditions
false
what are the sensory nerves in the dermis
free nerve endings
meissner’s corpuscles
pacinian corpuscles
what attaches the dermis to underlying musculoskeletal system
subcutis (hypodermis, panniculus)
what is the subcutis made up of
adipose tissue
collagenous and elastic fibers
what layer of the skin contains the hair follicles
adnexa
what part of the hair growth cycle is the growth period
anagen
what part of the hair cycle is the transition period
catagen
what part of the hair growth cycle is the resting period
telogen
what part of the hair growth cycle is the shedding period
exogen
true or false:
hair growth is affected by photoperiod
true
what nutrient is necessary for hair synthesis
protein
why would sick animals have more hair follicles in telogen
less protein synthesis = resting period
why would sick animals have more hair follicles in telogen
less protein synthesis = resting period
what are the types of sweat glands
apocrine
eccrine
which sweat gland opens into hair follicle “epitrichial glands” undergo apocrine secretion
apocrine
how does the apocrine secrete
membrane budding
which sweat glands are located on footpads on dogs and cats with “atrichial glands”
eccrine
how do eccrine sweat glands secrete
merocrine secretion
exocytosis
which type of gland opens into deeper area of hair shaft to lubricate the hair shaft under holocrine secretion
sebaceous glands
what is the most important barrier against infection and fluid loss
stratum corneum
what are the steps to regeneration and repair
- blood clotting
- inflammation
- RE-epithelialization
- fibroplasia
- angiogenesis
- wound contraction
- tissue remodeling
what is the purpose of inflammation
12-24 hours post injury
recruitment of inflammatory cells
how does re-epitheliazation occur
3-7 days post injury
keratinocytes migrate and proliferate to cover the wounds
what is re-establised do to re-epitheliaztion
basement membrane zone
what is the hallmark histologic feature of healing
granulation tissue
what is granulation tissue made up of
fibroplasia
angiogenesis
what is the transformation of squamous epithelial cells into the keratin layers of the stratum corneum, hair, nails
cornification
what type of lesion is flaky and scaley skin
hyperkeratosis
what is the classic case of primary disorder of cornification disorders
primary seborrhea of the cocker spaniel
what are considered secondary disorders of cornification disorders
-occurs as a response to chronic stimuli such as inflammation and trauma
-nutritional disorders (vitamin A deficiency)
true or false:
disruption of the stratum corneum predisposes to infections
true
what is acanthosis
epidermal hyperplasia
diffuse thickening of the epidermis with increased number of keratinocytes
what are 7 disorders of the epidermis
- cornification disorders
- epidermal hyperplasia
- dyskeratosis
- apoptosis
- necrosis
- dysplasia
7.atrophy
what disorder is the premature keratinization of epidermal cells
dyskeratosis
what disorder typically occurs with immune-mediated disorder
apoptosis
what are 2 common causes of apoptosis within epidermis
lupus erythematosus
erythema multiforme
what is the necrosis of superficial epidermis
erosion
what is the necrosis of full epidermis and partial dermis
ulceration
what disorder is abnormal development / alteration in size, shape and organization of keratinocytes
dysplasia
what can dysplasia be commonly seen with
ulceration and chronic inflammation
true or false:
dysplasia can precede to become malignant
true (carcinoma in situ)
what is the decrease in the number and size of keratinocytes
atrophy
true or false:
atrophy is a consequence of sublethal cellular injury
true
what is fluid accumulation between cells
edema
what is intercellular edema of the epidermis
spongiosis
what is spongiosis common with
epidermal inflammation caused by STAPHYLOCOCCUS or MALASSEZIA
what is keratinocyte swelling limited to the basal keratinocyte layer
hydropic degeneration
what are types of intracellular fluid accumulation
hydropic degeneration
ballooning degeneration
what is keratinocyte swelling within multiple layers
ballooning degeneration
what causes ballooning degeneration
epidermal damage and numerous viruses
what are the epidermal responses to fluid balance and cellular adhesion changes
- edema and intracellular fluid
- acantholysis
- vesicles
what is the disruption of intercellular junctions between keratinocytes of the epidermis
acantholysis
what is the result of acantholysis
dissociation of keratinocytes and formation of epidermal vesicles / pustules
what can cause acantholysis
type II cytotoxic hypersensitivity
what are 2 common type II cytotoxic hypersensitivities associated with acantholysis
pemphigus foliaceus
pemphigus vulgaris
where does pemphigus foliaceus commonly occur
superficial epidermis
where does pemphigus vulgaris normally occur
deep epidermis
what are fluid-filled spaces within or beneath the epidermis
vesicles
if the vesicle is >1cm, what is it called
bulla
if a vesicle pops, what is the result
ulcer left behind
what is commonly accompanied by spongiosis
epidermitis
what is inflammation of epidermis
epidermitis
what can accumulate within the epidermis and form intra-epidermal pustules
neutrophils
what is composed of dried fluid and cellular debris on the skin surface to indicate an exudative process
serocellular crusts
how can hyperpigmentation occur
increased production of melanin
increased number of melanocytes
what are the causes of alteration in epidermal pigmentation
hyperpigmentation
hypopigmentation
pigmentary incontinence
what causes pigmentary incontinence
loss of melanin by damage to the stratum basale with accumulation of melanin within macrophages
what are some disorders/ alterations in dermal growth and differentiation
- dermal atrophy
- fibrosis
- collagen dysplasia
- solar elastosis
what disorder leads to a decrease in the quantity of collagen and fibroblasts in the dermis causing a decrease thickness of the dermis
dermal atrophy
what causes dermal atrophy
caused by catabolic conditions
what is commonly seen with dermal atrophy
comedones
what disorder of the dermis is gradual deposition and maturation of collagen to form scar tissue
fibrosis
how does fibrosis form
proliferation of fibroblasts and newly formed collagen fibrils
what disorder is a rare inherited abnormality of collagen that results in decreased tensile strength and increased stretchability of the skin
collagen dysplasia
what is caused by chronic exposure to ultraviolet radiation leading to increased number of thick, interwoven, basophilic elastic fibers in the superficial dermis
solar elastosis
what are 3 abnormal deposits in the dermis
- amyloid
- mucin
- calcium
what deposition in the dermis is composed of glucosaminoglycans bound to hyaluronic acid
mucin
what are the 3 forms of calcium deposition
dystrophic
metastatic
idiopathic
which type of calcium deposition is a result of chronic injury or degeneration
dystrophic
which type of calcium deposition is a result of deposition of calcium in tissues during hypercalcemia
metastatic
what is an unknown cause of dermal calcification
idiopathic calcium deposition
