Lecture 14: Integument Flashcards
Integument includes
Skin and epidermal derivatives
Are antlers epidermal derivatives?
Nope
What is the largest organ of the body?
Skin
Functions of skin (9)
- Protection
- Prevents loss of water and electrolytes
- Temperature regulation
- Sensation
- Elasticity permits movement
- Immune function
- Excretion
- Calcium homeostasis
- Energy storage
Functions of hair (5)
- Insulation
- Camouflage
- Social display
- Sense/protect
- Sex recognition
What percent of body weight is skin
8-16%
Epidermis cells
Stratified squamous keratinized
Hypodermis binds
skin loosely to adjacent organs
Three regions of the skin
- Epidermis
- Dermis
- Hypodermis
Epidermis origin
ectodermal
Is epidermis vascular?
Nope
Dermis origin
Mesodermal
What regions are CT
Dermis
Hypodermis
Is dermis vascular?
Yes and innervated
Thick epidermis
- Digital pads, muzzle, ect
- Hairless
- Merocrine sweat glands
Thin epidermis
- Hair follicles with arrector pili muscle
- Sebaceous and sweat glands
Epidermal pegs/ridges
-Downward projections of the epidermis into the underlying dermis
Dermal papillae
- Upward projections of the superficial dermis
- Increased area of contact between dermis and epidermis
- Bring blood vessels near the epithelium
Sites of pegs and papillae
- Footpads, nasal planum, and scrotum
- Areas subject to traction stress
- Not in normal hair bearing skin of cats and dogs
What is the principle component of the dermis?
Connective tissue
Two layers of the dermis?
- Papillary layer
- Reticular layer
Papillary layer
- Loose CT
- Type 1 and 3 collagen
- Mast cells, macrophages, vessels, and nerves
Reticular layer
- Dense irregular connective tissue
- Type 1 collagen
- Network of elastic fibers
- Blood vessels, nerves
Skin elasticity
Network of elastic fibers in reticular layer of dermis