Dermatology Flashcards
whats the difference between superficial and deep fascia
superficial = subcutaneous
its fatty and loose
deep fascia = tough and sheet like
dense connective tissue, white and glistening appearance
name the 2 superficial veins of the upper limb and what aspect of the limb they travel on
cephalic vein - along the lateral aspect of limb
basilic vein - along medial aspect of limb
name the 2 superficial veins of the lower limb and what aspect of limb they travel on
great saphenous vein - along midline of leg
small saphenous vein - along posterior midline of lower leg
what is vena comitantes
when veins benefit from pulsation of the artery when enclosed in a vascular sheath
where is the most common area for venous ulceration to occur
the gaiter area - medial aspect of distal leg
what is the general pathophysiology of venous ulceration
venous blood pressure increases
damages blood vessels, which become leaky
proteolytic enzymes and free radicals released, which leak into surrounding tissue and damage it
skin breaks down but cannot heal due to the poor blood supply
where do all axillary lymphatics drain into
subclavian lymphatics
where do all lower limb lymphatics eventually drain into
the external iliac nodes –> common iliac nodes –> lumbar lymphatics
what cells is the epidermis made up of
ectoderm cells that form a single layer periderm
do the periderm cells remain attached forever
no - they cast off
what are the 4 layers that make up the epidermis
keratin layer - corneocytes, waterproof barrier 💦
granular layer - 2 or 3 layers of flat cells
prickle cell layer - has lots of desmosomes
basal layer - 1 cell thick, v metabolically active
what cell type is the majority of the epidermis made up of
95% keratinocytes - they are stratified squamous epithelium
what is the keratin Layer formed from
the terminal differentiation of keratinocytes to corneocytes
in which layer of the epidermis is the cell nucleus lost
the granular layer
at what stage in foetal development are the 4 layers of the epidermis created
16 weeks
when in foetal development are hair follicles and other appendages developed
26 weeks
what non-keratinocyte epidermal cells also reside in the epidermis
melanocyte
langerhans cells
Merkel cells
what structure do melanocyte cells contain that converts tyrosine to melanin
melanosomes
where do melanocytes migrate from in the first 3 weeks of development
from neural crest to epidermis
name the cell described as a pigment producing dendritic cell
melanocytes
where does the precursor for langerhan cells originate
the bone marrow
what layer in the epidermis to langerhan cells reside and what are they involved in
prickle cell layer
involved in the skin immune system
name the antigen presenting cell of the epidermis
the langerhan cell
which cells are known as mechanoreceptors and may become malignant
Merkel cells - they’re needed for the ‘light touch sensation’
they can become malignant Merkel cell carcinoma - caused by viral infection
what structures make up the pile-sebaceous unit
hair
hair follicle (the bit of hair under skin)
Arrector pilli muscle
sebaceous gland
name the 3 phases of growth in hair follicles
anagen - growing
catagen - involuting
telogen - resting (shedding phase)
what are the 3 layers of the demo-epidermal junction
lamina lucida
lamina densa
sub-lamina densa
what cells are found in the dermis
fibroblasts, macrophages, mast cells, lymphocytes and langerhan cells
which somatic sensory receptors detect pressure
pacinian receptors
which somatic sensory free nerve endings detect vibration
meissners endings
which skin gland produces the natural moisturiser sebum
sebaceous gland
which skin gland produces the oily fluid that goes on to become BO
apocrine gland - part of the pill-sebacous unit
which skin glands main purpose is thermoregulation and covers most of the body surface
eccrine glands
