Integumentary system Flashcards
what is the integumentary composed of?
The skin and its appenadages (including hair, scales, feathers, hooves and. nails)
examples of functions of the integumentary system
-protection
-sensation
-secretion
-absorption
-excretion
-cleaning
-reduces friction
-dehydration
-ultraviolet light
What are the three basic layers of skin
hypodermis
dermis
epidermis
function of the hypodermis (skin)
the deepest layer and its responsible for making new skin cells
function of the dermis (skin)
the middle layer of maturing cells
function of the epidermis (skin)
the outer most, superficial skin layer and the only one of the skin layers that sheds, or sloughs off, dead cells
functions of sebaceous glands
secretes an oily or waxy matter (sebum) to lubricate and waterproof the skin and hair of mammals
function of the sudoriferous (sweat) gland
secrete sweat to help with thermoregualtion.
In the ear there are ceruminous glands which secrete ear wax which protect the ear canal against physical damage and pathogens
function of the hair follicles
produce hair that aids in thermoregulation
function of blood vessels within the skin
nourish the cells and remove waste products
touch receptor -mechanoreceptors
-vibration and pressure (touch)
-Meissners corpuscles (light touch)
-Pacinian corpuscles (pressure)
Nociceptors -mechanoreceptors
-pain
-free nerve endings
Thermoreceptors -mechanoreceptors
-temperature
-vasodilation/constriction of blood vessels
-sweating
Define alpha keratins
found in all vertebrae and are relatively flexible and make up much of the mammalian skin, hair and nails
Define downy hair
soft, kinked and dense which lie close to the skin. this makes the undercoat which is essential for insulation.
define guard hair
long, thick, and coarse which makes the top of the coat. it is important as it protects the underlying skin and it also influences the animals appearance
how are nails formed
formed from a matrix at the top of the dermis - as the cells grow from the matrix the older cells are pushed out.
what are beta-keratins
unique reptiles and birds as they tend to be tougher and less flexible, the function is to prevent desiccation and for waterproofing
structure of the feathers
-consist of central hollow shaft that then becomes the rachis
-barbs branch from the rachis forming a flattened surface (vane)
-the barbs possess further branches called barbules
-these contain structure like hooks that attach to one another reinforcing the structure of the vane
feathers divide into seven broad categories:
wing feathers (regimes)
tail feathers (rectrices)
contour feathers
semi plume
down
filo plume
bristle
function of wing feathers
specialised for flight
function of tail feathers
arranged in a fan shape, support precision steering in flight
function of contour feathers
cover the bird body, contour feathers can also help the bird show off or stay camouflaged
function of the semi plume feathers
hidden beneath other feathers on the body, semi plumes create fluffy insulation
function of down feathers
relatively short, positioned closest to the body where they trap body heat
function of filo plume feathers
short simple feathers, function like mammals whiskers to sense the position of the contour feathers
function of the bristle feathers
simplest feathers, found on the head, bristles may protect the birds eyes and face