integ 1 Flashcards
wht does the inetg syste consist of
skin hair nails various glands
waht are the two major parts fot he inetg sys
cutaneuos membrane
acessory structures
wahts the cutaneous membrane
sepidermis and dermis
wahts in the accesssory structures
glands ducts hairs
what are the 5 major functions of the integ syste
protection
temp maintenance
synthesis and storage of nutrients
sensory reception
excretion/secretion
whats the general structure of the integ sys
three layers:
epidermis
dermis
hypodermis
what are the properties of epidermis
layers (strata)
avascular
what does the avascular nature of the epidermis cause
relies on diffusion of nutrients from capillaries in dermis
cells with hihgest metabolic demands lie closest to basement membrane
where do keratincytes originate from
deepest layer of epidermis - stratum basale
they migrate upwards until they are eventually shed from the surface of th eskin
what does the epidermsi consist of
stratified squamous epithelium
primary cell type - keratinocytes
how is the epidermis and dermis sepertaed
by a basement membrane
waht are the skin layers from the basement membrane towards the free surface
Stratum basale,
three intermediate layers, stratum corneum.
properties of the stratum basale
deepest epidermal layer
how is the stratum basale attached to the basement membrane
using hemidesmosomes
form epidermal ridges which increase the bond strength and surface area
waht cells are found in the stratum basale
large stem cells - basal cells
merkel and melanocytes
what does the stratum spinosum consist of
keratinocytes held together by desmosomes
branched dendritic cells
what happens to the cells in the stratum granulosum
cells stop dividing and begin to make large amounts of protein keratin
what are the Properties of the cells found in the stratum lucidum
flattend cells
densley packed
filled wiith keratin
only found in thick skin
properties of the cells in stratum corneum
layers of flat dead keratin filled epithelial cells
tightly connected by desmosomes
what leads to corns
excessrive production of keratin
why and where are corns formed
localised areas of excessive keratin production that form in areas of thun skin
what does the dermis consist of
superficial paillary layer
deeper reticualr layers
what does the papillary layer in the dermis consist of
aerolar connective tissue - supports and nourishes epidermis
capillaries lymph vesssels and sensory neurons
properties of the reticular layer in the dermis
irregular dense connective tissue
collagen fibres extend into papillary layer above and deep into hypodermis
fibroblasts
accessory organs
