Skin Flashcards
(28 cards)
Name the three layers of the skin
epidermis
dermis
hypodermis
what is hypodermis made of? what is its function?
adipose tissue and loose connective tissue
energy
insulation
shock absorber
make hormones such as leptin
connect skin to underlying muscle and bone
What layers are in the dermis? What is its function?
top- papillary dermis
reticular dermis
dermal papillae
contains structures such as hairs, sweat glands, sensory structures
Name the layers of the epidermis top to bottom
s. corneum
s. lucidum (palms + soles of feet only)
S. granuloseum
s. spinosum
s. basale
What are the epithelial cells of the epidermis held by?
adherens
What is the S. corneum made of/ function?
squames (dead keratinocytes)
prone to injury
continuously shed
What is the S. lucidum made of/ function?
very thin palms and soles only
What is the S. granulosum made of/ function?
stratified squamous epithelium
lamellar granules
tonofibrils
What is the S. spinosum made of/ function?
cuboidal epithelial cells held together by desmosomes
produce lamellar bodies
golgi apparatus first appears
What is the S. basale made of/ function?
tall columnar
cell division cells differentiate and migrate + differentiate to keratinocytes
What is the normal transit time of a keratinocyte from basale to corneum? what happens in psoriasis ? what is it called when too much keratin produced?
28-40 days
time reduced in psoriasis to silvery scales
corneum replaced every 2-3 days
hyperkeratosis
Name three other cells in the epidermis and their function
melanocytes- produce melanin (pigment)
langerhans cells- specialised antigen presenting cell to mediate immune reponse
merkel- mechanoreceptors
Name the four types of skin. what is the generalisation often made?
hair non-hairy thin thick hairy often thin non-hairy often thick
Describe the differences between hairy (thin) and non-hairy (thick) skin
thick (non-hairy):
no hair follicles/ sebaceous glands/ arrector pilli muscles
s. corneum thicker and dermis thinner
increase no mechanoreceptors
found palms/ soles/ between fingers and toes
ridges and furrowsregualr dermal papillae
s lucidum seen
thin (hairy): hair follicles/ sebaceous glands/ arrector pilli muscles present smaller ridges and furrows irregular dermal papillae s. lucidum absent
What are skin appendages? name a few.
skin associated structures that serve a particular function hairs arrector pili muscles sebaceous glands sweat glands nails
Name the three types of hair and when they are found.
lanugo- fetus
vellus- replaces lanugo
terminal - head scalp etc due to testosterone
what are the main functions of hair?
thermoregulation
sexual attraction
sensation
protection
What are arrector pilli muscles?
SM fibers attached to papillary region of dermis (origin) and hair bulb (insertion)
contraction causes goose bumps
What are nails made of and what are their function?
alpha keratin
protect
help with sensitivity and pressure
What do free nerve endings detect?
pain
what do tactile discs detect?
touch pressure texture
what do meissner corpuscles detect?
tapping and flickering movements
what do pacinian corpuscle detect
vibration
what do ruffini corpuscle detect
joint movement and tissue stretch
