Special Skin Flashcards
what are the 5 layers of hair follicle
Hair shaft
intnerla root sheath
external root sheath
glassy membrane
fibrocollagengous connective tissue
what is below the hair follicle
Hair bulb
what is below the hair bulb
dermal hair pailla
what are the different areas of hair shaft
medualla - soft keratin
cortex - hard keratin
Cuticle
anagen
growth period of hair
what is telogen
inacivtity period of hair
catagen
regression period
what adds pigment to the hair shaft
mealocytes in the hair bulb
what happens to internal root sheath at the level of sebaceous gland
degenerate
before the sebaceous gland
it will grow along the hair shaft
what does the basal membrane seperatate
hair follicle + dermis
what is the arrector pilli muscle
smooth muscle
where is it
midpoint of the outer connective tissue sheath to the dermal papillae
what does it reiceve information from
symapethic nervous system
causing isolation
what type of glands are sebaceous gland
holocrine glands
simple or branches alvolear
what do they produce
sebum
what does this help
help with skin become supple and water resistance
what do they look like
pale staining ovoid masses with thin connective tissue capsule with a central nuclei
what is the sebum
lipid rich dedecamped cells
what is the function of sebum
it is oily mixture which helps make skin supply and water resistiant
what surrounds each alveolous
thin connective tissue
what do the alveolous open up into
common duct that are lined with stratified squamous epithelium which is continuous with the outer epithelial sheath o fthe hair follicle
once being released where do the sebum go
to the skin surface
what does each sebaceous gland contain
a peripheral layer of mitcocially active cuboidal cells
what does this give rise to
allows the accumlation of large amount of lipids in the cytoplasm
what is the pilosebceous unit made of
hair
hair follicle
sebaceous glands
arrector pili muscle
what do the keratinocytes that make up the hair bulb cosntalty undergoing
kernisation differintion into spefific hair types
what does thick hair form
they form medualla
How is a medulla formed by
central region of the root produce large vaculoated keratinsied cells
what forms the cortex
differeination into heavy kernatised groups of cells form the cortex
what forms thr cuticle
the peripheral cells that are heavily keratinised form the cuticle
what does the internal root sheath compelelty surround
the intiial part of the hair shaft
what does the external root sheath cover
the internal sheath
where does it extend to
all the way to the epidermis
what is it continuous with there
the basal and spinous layer
what is the glassly membrane
thickened basement membrane
what does the surrounding dermis form
connective tissue sheath
what do the cells in the hair root do
differeiantiate into hair medulla coretex and cuticle
what is asscoatied with the hair follicle - gland
apocrine gland
what do the sebaceous glands lack e
myoepthelial cells
what attaches to their capusles
arrector muscle
what does this allow
compression of the gland to expel sebum into the hair follicle neck
what is sweat glands dervied from
eptihelial embedded in the dermis
what are the two types of sweat glands
eccrine sweat glands
apocrine sweat glands
where is eccvtrne found
what is their secretion
widley distrubted across the body (thick skin)
located dermis and hypodermis junction
watery sweat from gland onto the surface
apocrine - where are they found
what do they produce
restricted mainly to the axillae and pernineum
produce a more protein rich secretion with pheromonal properties
what is apocrine innverated by
adrengeric nerves endinds
what does eccrine recieve
chloingeric fibres
what types of glands it he eccrine sweat gland
coiled tubular gland
have small lumens
what type of epithelium is present of the secretory potion
stratified / puesodestated epitehlium
what is lighter the seceretory or the duct segment
secretory
what are the function of clear cells
columnar cells that produce sweat
what gets transported through the clear cells
intersisital fluid from the capillary rich dermis aroun the gland
what happens then
put in either direclty into the lumen or into intercellular canalucli that open to the lumen
where are dark cells found
line the luminal surface but DO NOT touch the basal lamina
what are dark cells filled with
mucoid and filled with glycoportiens containing grnaules
what is the function of the dark cells
innaite immunity with bacteridial activity
where is the meyoepithelial cells
on the basal lamina
what is there function
help discahrge secretion tinto the duct
what are the different layers of the ecccrine sweat gland
one more acidphillic with mitchodnria
Where are apocrine sweat glands found
axillae / gentilia
where do their ducts end
on the hair shaft
what do they produce
protien rich secretion with pheromonal properties
the secretory portion of the apocrine has a much larger what
lumen
what type of epithelial is the secretory portion of the aprocine sweat gland
simple cuboidal esophillic cells
where does the duct typically end
end of the hair shaft
What is the nail root
proximal part of the nail
covered by skin fold
what forms the cuticle
epidermal stratum corneum exneding onto the proximal nail
what is the nail plate (kerantised) bound to
epidermis called the nail bed
what does the nail bed contain
basal and spinous layers
what does the nail plate arise from
the nail matrix
the is the lunula
proximal area of the nail
how does divsison occur
divide and move distallty and become ketainsie forming the name root
what does this mature as
a nail plate
what is the hypoychium
becomes free of the nail bed at the epidermal fold
what are the 3 plexus of the skin
superfifical papillary plexus
deep reticular plexus
subcutaneous plexus
what is the supefifical papillary plexus
subepidermal network of arterioles under the dermal paillae blood to the cpillary loop in each papillw
what is deep reticular plexus
small arteries veins and capillaries in the retcualr layer of the dermis
what is the subctuaneous plexus
muscualar arteries and veins in the hypodermis network parallele to the skin surface
what is glomus bodies
arterivenous shiunts in the deeper dermis - speically the lips and toes
what is the function of the glomus bodies
peripheral temperature regulatiomn
how do they do that
divert blood from superififcal into deep plexus to reduce heat loss
where does the lymapthic of occpuy
the venules
where are they also located
in deep and superififcal plexuses
what are the types of nerves
free or exncapulared nerve endings
Free Nerve endings what are they
can be myelinated or non meyleianted
what are they reponsible for
pain and itch senation and detcing tmepratur
where are they found
papillary dermis and send twigs into the epidermis where some of them associte with mekel cells
what does this cause
them to act as slowly adapting mechaism
what else do they do
Free nerve endings also ramify around hair follicles, in the perifollicular fibrous sheath, and some penetrate into the external root sheath.
wha tis Meisnners corupsules
: are rapidly adapting mechanoreceptors responsible for touch sensation. They are particularly prominent in the papillary dermis of the pulps of the fingers and toes, and soles and palms
what is paciain corpsule
are responsible for detection of deep pressure and vibration. In the skin they are usually found deep in the subcutis, singly or in small clusters, being particularly numerous in the palms and soles
thin and thick
epidermal ridges are shallow in thin
keratin is thin
contains hair follicles and sweat glands
