unit 4 anatomy SKIN Flashcards
body membranes
epithelial membranes
composed of epithelial tissue and an underlying layer of connective tissue
connective tissue membranes
composed largely of various types of connective tissue
cutaneous
skin
serous membranes
simple squamous epithelium on a connective tissue basement membrane
parietal
line walls of body cavities
viscera
cover organs found in the body cavities
mucous
line body surfaces that exit the body
connective tissue membranes
do not contain epithelial components
produce a lubricant called synovial fluid( a thick liquid located in joints)
examples are the synovial membranes in the spaces between joints and in the lining of bursal sacs
structure of the skions
epidermis
skin pigment
dermal epidermal junction
dermis
subcutaneous tissues
the brown pigment MELANIN is produced by specialized cells in this layer
causes by UV light
it produces pigmentation in the skin
accessory organs of the skin
hair
nails
skin receptors
hair
soft hair of fetus and newborn is called LANUGO
epidermal tubelike - hair follicle
hair growth - papilla
visible part of the hair - shaft
arrector pili - specialized smooth muscle/ causes hair to stand upstraight
nails
produces by epidermal cells over terminal ends
visible parts is called nail body
root lies in a groove and is hidden by cuticle
crescent shaped area nearest root is called lunulla
nail bed may change color with change in blood flow
skin receptors
specialized nerve endings: make it possible for skin to act
lamellar corpusle; capable of detecting pressure
tactile corpuscle; capable of detecting light touch
skin glands
eccrine sweat glands
most numerous, important and widespread of the sweat glands
produce perspiration or sweat, which flow out through pores on skin surface
function throughout life and assist in body heat regulation
apocrine sweat glands
found primarily in the skin in the axilla
larger than eccrine glands
thicker secretion
armpits
Sebaceous glands
SEBUM ( NATURAL SKIN MOISTURIZER)
secrete oil for the hair and skin
grow where hairs grow
tiny ducts open into hair follicles
sebum secretion increases during adolescence
function of the integumentary system
protects (from bacteria or wounds)
pain receptor
temperature regulation
excretion( sweat glands)
vitamin D synthesis
protection: first line of defense against
infection by microbes
ultraviolet rays from sun
harmful chemicals
cuts and tears
temperature regulation
skin can release almost 3000 calories of body heat per day
mechanism of temperature regulation
regulation of sweat secretion
regulation of flow of blood close to the surface
sense organ activity
skin functions as an enormous sense organ
receptors serve as receivers for the body, keeping
it informed of changes in its environment
excretion
body rids itself of wastes
excess vitamins, drugs, and hormones can be excreted onto the skin by sweat
synthesis of vitamin D
occurs when skin is exposed to ultraviolet light
vitamin D is critically important health
The dermis is connected to underlying structures via a subcutaneous tissue
Dermis = support = flexibility
consist of collagen and elastin
epidermis acts like a barrier
it has a keratin - a tough and water insoluble structural protein
The dermis is well vascularized and contains sensory nerves, hair follicle, sebaceous, blood vessels, and sweat glands
it has 2 zones =
upper papillary dermis with loose connective tissue
lower reticular dermis with denser connective tissue
The skin
protective barrier
sensory function
prevents water loss
thermoregulation
the hypodermis provides thermal insulation, padding, and serves as the body main energy storage
thick skin has 5 epidermal layers
thin skin has 4 epidermal layers
epidermis = mostly keratinocytes (80%)
stranum corneum = cornified layer
stratum granulosum = granular layer
stratum spinosum = spinous layer
stratum basal = basal layer
the skin turns a blue-gray color—a condition called .
cyanosis.
