Dermo-Epidermal Junction and Structure and Function of Dermal Components Flashcards
what is the function the dermo-epidermal junction
support anchorage adhesion growth differentiation of basal cells semi-permeable - filters and protects against invading microorganisms
what makes up the dermis
ground substance
cells
fibres
muscles, blood vessels, lymphatics, nerves
what is ground substance
a supportive water-based substance in the epidermis
what cells are in the dermis
mainly fibroblasts macrophages mast cells lymphocytes langerhans cells
what types of fibres are in the dermis
collagen mostly
elastin
what is photoaging
sun exposure causes loss of collagen and skin sinking
describe the blood vessels of the skin
they supply the epidermal skin but never cross into it, they run along the DEJ
they contain many horizontal plexuses and are more than needed for metabolic needs
what supports the DEJ blood vessel walls
collagen and muscle
what type of somatic sensory (dermatomes) nerves are there in the skin
free nerve endings and special receptors
what are the special receptors of somatic sensory and their function
Pacinian corpuscles - pressure
Meissner’s corpuscles - vibrations
what does the ANS supply in the skin
blood vessels
nerves
glands
where are Pacinian corpuscles
deep dermis
what do motor neurones supply in the skin
sweat glands
what do free nerve endings detect
light touch
what is a pilosebaceous unit
specialised keratin with an adjacent sebaceous gland
what is the oil in hair used for
lubrication
maintaining integrity of hair shaft
closes gap and reduces risk of infection and irritation
what is secreted by sebaceous apocrine eccrine glands
oil
pheromones?
sweat
describe the location of apocrine glands
feed directly into hair follicle
under arms and groin
where are eccrine glands and what triggers them
many - hands, soles, forehead and axillae
warmth, stress
are sebaceous gland endo or exocrine and where do they secrete into
exocrine
piliary canal
where are sebaceous glands most widely distributed
face, chest and back
what do sebaceous glands produce and what does it consist of
sebum
squalene, wax, esters, TG and FFA
what is the function of sebaceous glands
control moisture loss and protect form infection via their antibacterial properties
what type of glands are
hormone sensitive
hormone dependent
sebaceous
apocrine (androgen)
what do apocrine glands produce
oily substance
it produces odour when anaerobic bacteria decompose
what controls eccrine glands
sympathetic cholinergic nerves
what can trigger eccrine glands
mental (stress)
thermal (warmth)
gustatory (spicy)
what is the function of eccrine glands
filter fluids - NaCl and HCO3
cools via evaporation and moistens palms/soles tp aid grip
secretes salty solution
what are the 2 layers of the dermis and what are they made up of
papillary dermis - superficial
- highly vascular loose connective tissue
retinacular dermis - deep
- thick dense connective tissue
what is the hypodermis and what does it consist of
layer of fat that lies immediately beneath the dermis
consists mainly of adipocytes, nerves and blood vessels
where are sebaceous glands derived from
epidermis
describe each gland histologically
sebaceous - lobulated mass in dermis
eccrine - coiled tubular structures
apocrine - open into hair follicles
