the integumentary system Flashcards
what are some key roles the skin plays a part in
protection from external environment
sensory
absorption
secretion
body temp regulation
what are the 3 layers to the skin (outermost to innermost)
epidermis
dermis
hypodermis
what are 4 charcterostics of the epidermis
outermost layer
epithelial
non vascular
protective
what kind of tissue makes up the dermis
fibrous connective tissue
what are the two gland structures present in the dermis
sweat and sebaceous
what systems are involved in the dermis
vascular and sensory
what are some charcteristics of the hypodermis
not skin
protective
adipose tissue
connective tissue
what is the structure of the epidermis (outermost layer)
thick keratinised squamous epithelium
how mnay layers is the epidermis composed of
5
how many cell types make up the epidermis
4
what are the 5 layers that make up the epidermis (innermost to outermost)
stratum basale
stratum spinosum
stratum granulosum
stratum lucidum
startum corneum
what are the 4 cells that make up the epidermis
keratinocytes
melanocytes
merkel cells
Langerhan’s cells
what occurs in the stratum basale (innermost layer)
cells divide by mitosis
what occurs in the stratum spinosum
keratin fibres and lamellar bodies accumulate
what occurs in the stratum granulosum
karatohyalin and a hard protein envelope form
what do dead cells contain in the stratum lucudim
dead cells containing keratohyalins
stratum corneum
the dead cells with a hard protein envelope contain what
keratin
what do keratinocytes produce
keratin
keratinocytes arise where
stratum basale
how are keratinocytes pushed to the surface
continouosly mitotic cells reproduce
how are keratinocytes able to be involved in wound healing
they have stem cell like properties
how are keratinocytes connected (what cell junction)
desmosomes
what is the name given when fillagrin causes keratin fibres to dimerise
keratinisation
what is keratinisation
filagrin causes keratin to dimerise
filagrin mutations can disrupt what process
keratinisation
where was the study conducted that there was found to be a link between filagrin mutations and eczema and asthma
dundee
how are people who have severe asthma have eczema
greater risk of exposure to allergens absorbed through the skin inhaled in the air
what is the primary role of the melanocytes
produce pigment and melanin
where are melanocytes found
stratum basale
what cell do melanocytes transfer the melanin to
keratinocytes
what are merkel cells
neuroepithelial cells associated with sensory nerve endings
what do merkel cells act as
mechanoreceptors
what neurotransmitter do merkel cells use
glutamate
what are merkel cells sesnitive to
shear and pressure
merkel cells accumulate at ridges in finger prints and hair endings to form what
a tactile disk
where are langerhanns cells made
in bone marrow
where do langerhans cells migrate to after being made in the bone marrow
epidermis
what system are langerhand=ns cells associated with
iimune system
how is melanin synthesised
synthesised by tyrosine
where does melanin synthesis occur
melanocytes
melanin synthesis can generate two end produvts with different colours
euelanin - _____
pheomelanin - ______
eumelanin = black
pheomelanin = red
UVA penetartes through what layer of the skin
dermis
UVB and UVC are extremely damaging and cause what
sunburn
once the re has been DNA damage to the dermis from UV - damaged dermal cells stimulate what hormone
alpha melanocyte stimulating hormone
melanin synthesis
synthesises by tyrosinase conversion of tyrosine through multiple reactions to _____ and then melanin
O-quinone
how do you develop carotene
from diet
what is erythema
re direction of blood flow t superficial skin cappilaries, due to irritation or infection
how do you get nervous erythema (blushing)
catecholamine induced vasodilation which pushes blood to the skin
how do you get jaundiced
liver disease releases bile pigments to blood deposited in the hypodermis and the cornea of the eye gives a yellow colour
how does brusing occur
injury to cappilaries of dermis and hypodermis results in deposition of bilirubin in skin which causes colours of a bruise
the strength of the dermis come from what 2 layers
papillary and reticular
what are the 5 different skin appendages glands
eccrine
apocrine
sebaceous
ceruminous
mammary
what are are hair cells made up of
keratin
how many phases are there in hair growth
3
what are the three phases of growth for hair
rest
growth
cesstation
what are nails made up of
keratin
what are nails for
protect fingertips from damage
aids precision of movemet
