structure and function of skin Flashcards
what is the largest organ in body?
skin
what is the skin’s outer layer?
epidermis
what layer is beneath the epidermis?
dermis
what type of epithelium is the epidermis made from?
stratified squamous epithelium
which germ layer forms epidermis?
ectoderm
what germ layer forms the dermis?
mesoderm
what are melanocytes?
pigment producing cells
what cell makes up most of epidermis?
keratinocytes
name cells that you might find in epidermis?
keratinocytes
melanocytes
langerhans cells
merkel cells
what are the 4 layers of the epidermis?
keratin layer
granular layer
prickle cell layer
basal layer
name a place where keratin layer would be thicker?
sole of foot
what layer does this describe?
2-3 layers large keratohyalin granules odland bodies high lipid content origin of cornified envelope cell nuclei lost
granular layer
what layer is water proof?
keratin layer
what do desmosomes do?
anchor cells to each other
what are blaschko’s lines?
developmental growth pattern of skin
what does loss of appendages cause?
scar tissue
name some appendages?
hair
nail
glands
mucosae
where to melanocytes migrate to and from during first 3 months of foetal development
from epidermis to neural crest
what are the organelles in melanocytes?
melanosomes
what does melanin absorb?
light
what is vitilgo?
autoimmune disease with loss of melanocytes
what is albinsim?
genetic partial loss of pigment production
what is nelson’s syndrome?
melanin stimulating hormone is produced in excess by pituitary
what is the function of the langerhans cell?
antigen presenting
picks up antigen in skin and circulates it to lymph nodes
what causes merkel cell cancer?
viral infection
what are merkel cells?
mechanoreceptors
what does anagen mean?
growing
what does catagen mean?
involuting (going down)
what does telogen mean?
resting
what is alopecia?
autoimmune hairloss
what makes nails/
specialised keratins
what is the dermo-epidermal junction?
interface between epidermis and dermis
what gives the epidermis its blood supply?
the dermis
what are the main cells in the dermis?
fibroblasts
what other cells do you get in the dermis?
fibroblasts macrophages mast cells lymphocytes langerhans cells
localised overgrowth of blood vessels
angioma
what do pacinian receptors detect?
pressure
what do meissners receptors detect?
vibration
what do free nerve endings detect?
touch and temp
what is neurofibromatosis?
overgrowth of nerve endings (thickened)
what do the apocrine glands secrete?
odour when you start puberty (in armpit and groin)
what to eccrine glands secrete?
sweat
what do sebaceous glands secrete?
sebum
what is sebum?
body’s natural moisturiser
what can sebum cause?
acne
what is toxic epidermal necrolysis?
acute skin failure
name some functions of the skin?
barrier function metabolsim and detox thermoregulation immune defence communication skills sensory skills
what happens if skin barrier fails?
fluid loss leading to dehydration
protein loss leading to hypoalbuminaemia
infection
what happens if skin thermoregulation fails?
heat loss leading to hypothermia
what happens if the skin immune defence fails?
infection
is skin metabolically active?
yes Vitamin D and thyroid hormone metabolism occurs
