Integumentary System Flashcards
the process of cells dying in order to form the vital protective barrier that helps enable the animal’s survival
Keratinization
What is another name for the Integumentary System
The Common Integumentary System
List the 7 functions of the Integument
- Prevent desiccation
- Prevent infection
- Thermoregulation - vasoconstriction vs vasodilation
- Excretion - water, salt, organic wastes
- Sensation - touch + pressure > input to CNS
- Vitamin D synthesis
- Storage - nutrients
the outer, non-vascular layer of skin that acts as a waterproof shield
Epidermis
the deep, vascular layer of skin that makes up the majority of skin
Dermis
the 3rd layer of the integument that acts as a thermoinsulator and a mechanical shock absorber
Hypodermis (Subcutaneous Layer)
separates the two layers of the integument
Epithelial Basement Membrane
What are the 4 components of the common integument?
- Epidermis
- Dermis
- Hypodermis
- Epithelial Basement Membrane
cells in the epidermis that produce a tough, fibrous, waterproof protein that gives skin its resiliency and strength
Keratinocytes
What are the majority of cells found in the epidermis?
Keratinocytes
long-reaching cells in the epidermis that produce pigment to be used by keratinocytes
Melanocytes
a dark pigment stored in membrane bound granules that is used to protect keratinocytes from UV rays
Melanin
membrane-bound granules that store melanin
Melanosomes
epidermal-specific macrophages that phagocytize microinvaders and stimulate other aspects of the immune system
Langerhans Cells
half-dome cells found at epidermal-dermal junctions that aid in the sensation of touch
Merkel Cells
the combination of a Merkel cell and a sensory nerve ending
Merkel Disc
What 3 types of cells are commonly affected in skin cancer?
- Squamous Cells
- Melanocytes
- Basal Cells
List 3 common skin cancers seen in vet med
- Malignant Melanoma
- Squamous Cell Carcinoma
- Basal Cell Tumors
a deadly form of skin cancer that results from abnormal changes in the genetic programming of melanocytes
Malignant Melanoma
What species is commonly affected by Malignant Melanoma? What 3 locations do the nodules appear?
- Aged grey horses
- Under tail base, in perianal areas, in the scrotum
a malignant form of skin cancer that is aggressively invasive locally, particularly to local lymph nodes
Squamous Cell Carcinoma
What visible symptom does squamous cell carcinoma produce?
circular, ulcerated lesions
Squamous cell carcinoma is common in what 5 species?
- Dogs
- Cattle
- Horses
- Cats
- Merino ewes
slow-growing tumors that stem from the basement layer of the epidermis, in hair follicles, and in sebaceous glands that do not spread but are recurrent
Basal Cell Tumor
What is the most common tumor found on cats?
Basal Cell Tumor
List the 5 layers of a Furless Epidermis from deepest to most superficial
- Stratum basale (basal layer)
- Stratum spinosum (spiny layer)
- Stratum granulosum (granular layer)
- Stratum lucidum (clear layer)
- Stratum corneum (horny layer)
How many layers do fur-covered and furless epidermises have?
Fur-Covered = 3
Furless = 5
knoblike elevations throughout the epidermal surface that are associated with special hairs important in the perception of touch
Tactile Elevations (epidermal papillae)
special hairs important in the perception of touch
Tactile Hair (tylotrich hairs)
dermatitis caused by tiny mites that live on or in the skin and results in irritation, pruritus (itchiness), and alopecia
Mange
How do you diagnose mange?
- Scrape skin with a DULL scalpel blade
- Transfer scrapings to a microscopic slide
- Examine via microscope
- Diagnose which type of mite it is
long, thin, mange-causing mites with stubby legs that live in hair follicles and sebaceous glands
Demodex Mites
round-bodied, mange-causing mites that burrow into oozing raw patches of the skin and result in agonizing itchiness
Sarcoptes
the species of mite that causes scabies or mange in humans, dogs, foxes, horses, and cattle
Sarcoptes scabiei
small, round-bodied mites that burrow into oozing raw patches of the skin and are common in cats, rats, and rabbits
Notoedres
What are the 3 types of fibers found in the dermis?
- Collagen Fibers
- Reticular Fibers
- Elastin Fibers
What are the 2 layers of the dermis?
- Papillary Layer - superficial
- Reticular Layer - deep
Why are tension lines important for surgeons?
Incisions heal best when made in the direction of the bundles > fewer fibers are disrupted > less scar tissue is needed for healing
references on the skin that indicate the separations between collagen fiber bundles of the dermis
Tension Lines
references on the skin that indicate areas of bending, typically in joints
Dermal Folds (Flexure Lines)
permits the skin to move freely over underlying bone + muscle without putting tension on the skin that would result in tearing
Hypodermis (Subcutaneous Layer)
a type of touch receptor sensitive to heavier pressure that is found in the hypodermis
Pacinian (Lamellated) Corpuscle
the presence or absence of melanin granules in the armlike extensions of the melanocytes
Pigmentation
Where do keratinocytes arrange melanin and why?
- on the side of the cell with the most sun exposure
- melanin protects from UV rays
the hormone that dictates the level of pigmentation by controlling the dispersion of melanin granules
Melanocyte-Stimulating Hormone
What type of papillae and sweat glands are found on and in paw pads?
- Conical papillae
- Eccrine Sweat Glands
foot pads that reside on the caudal surface of the “wrist”
Carpal Pads
the central weight-bearing pads of the feet
Metacarpal + Metatarsal Pads
foot pads that protect each of the digits
Digital Pads
the top of the nose in cats, pigs, sheep, and dogs
Planum Nasale
the muzzle of cows and horses
Planum nasolabiale
dark brown, horny structures on the inside of each leg at the carpus of the forearm and at the tarsus of the hind leg
Chestnuts
dark brown, horny structures found in the fetlock
Ergots
infoldings of the skin containing fine hairs, sebaceous glands, and oil glands that are primarily found on sheep
Cutaneous Pouches
List the 3 types of cutaneous pouches commonly found on sheep
- Infraorbital Pouches
- Interdigital Pouches
- Inguinal Pouches
infoldings of the skin found in front of the eyes of sheep
Infraorbital Pouches