The Integumentary System
Skin consists of 3 major regions
Epidermis - outer
Dermis - middle
Hypodermis (superficial fascia) - deepest
Epidermis is composed of
keratinized stratified squamous epithelium
Keratinized stratified squamous epithelium consists of
4 district cell types and 4-5 layers
4 types of epidermis cells
merkel cells are...
touch receptors in association with sensory nerve ending
langerhans' cells are...
epidermal macrophages that help activate the immune system
producers of the brown pigment, melanin
excess melanin in one spot =
produce the fibrous protein keratin and are the abundant top layer of the epidermis
layers of the epidermis
stratum lucidum is a clear layer that is only found....
in thick skin (palms, fingers and feet)
stratum corneum is
the outer (horny) layer constantly being rubbed off
stratum basale layer is the _____ and is attached to the _________
how does the basale layer receive nourishment
via diffusion from the dermis
why is the basale layer also referred to as the germinativum layer?
because the cells in this layer are constantly undergoing rapid division
basale cells are small
false. basal cells are LARGE
statum spinosum (the prickly layer) recieves ______ from the dermis
which 2 cells are abundant in the sinosum (prickly) layer?
melanin and langerhans'
why do the cells appear spiky in slides?
because their desmosomes hold tight while cells shrink back
the cells in which layer contain a weblike system of intermediate filaments attached to desmosomes?
the prickly (spinosum) layer
why do the upper portion of the granulosum layer die?
because the cells do not receive much nourishment from the dermis
the stratum granulosum is a thick layer
false. it's a thin layer
stratum lucidium is a dead layer
what's the other name for the horny layer?
is the stratum corneum dead or alive?
what are the 2 functions of the horny layer?
waterproofing + protection
which layer of the skin contains strong, flexible CT?
the dermis contains blood supply and ___________
what is the dermis' relationship to the epidermis?
it keeps the epidermis alive
what types of cells are in the dermis?
fibroblasts, macrophages, mast cells and white blood cells
the dermis is composed of 2 layers, what are they called?
papillary (finger-like) and reticular (net-like)
what are the 3 pigments that make up skin color?
melanin, carotene and hemoglobin
what color is hemoglobin responsible for?
what color is carotene responsible for?
what color is melanin responsible for?
yellow to reddish brown to black
what is happening when the skin is appearing blue?
why does cyanosis happen?
it occurs when there is low oxygen concentration
in darker skinned people how is cyanosis visable?
in mucous membranes and nail beds
when sebaceous glands are stimulated by hormones they...
where are sebaceous glands not found?
on the hands and soles of the feet
what do sebaceous glands secrete?
what are the modified apocrine glands that are found in the lining of the external ear canal?
which glands are confined to the axillary (armpit) and anogenital regions?
what are the sweat glands that are mainly found in the palms, soles of the feet and forehead?
hairs (or pili) are flexible strands produced by