Structure of the skin Flashcards
what are the 3 layers of the skin?
epidermis
dermis
hypodermis
What type of epithelia is found in the skin?
Keratinised stratified squamos epithelium
What are the 5 layers of the epidermis?
stratum corneum stratum lucidum stratum granulosum stratum spinosum stratum basale
What are the two types of skin
hirstute-hairy
glaborous- no hair, thick skin, lots of keratin
What are keratinocytes?
Specialised epithelia that secrete keratin
What is cornification?
The upwards movement of keratinocytes accompanied by structural changes
What other cells can be found in the epidermis?
Langerhans
melanocytes
merkel cells
Free nerve endings
What is the function of merkel cells?
mechanoreceptors sensitive to light touch in the epidermis
What are the two layers of the dermis? What are their differences?
papillary
reticular- thicker, more collagen and elastin fibres
What structures are found in the dermis?
sebaceous glands hair follicles erector pili pilosebaceous units sweat glands (eccrine and apocrine) blood vessels cutaneous sensory nerves
What are sebaceous glands?
secretory glands that relax an oily lubricating wax called sebum
What is a pilosebaceous unit?
sebaceous gland + hair follicle
What is the difference between eccrine and apocrine glands?
Eccrine secrete directly onto skin
Apocrine secrete into hair follicle duct
Whats the function of an eccrine gland?
secrete clear, odourless sweat
thermoregulation
Whats the function of an apocrine gland?
found in genitals/axilla
produce body odour
What are the 3 main cutaneous sensory nerves?
Meisenners corpuscule
Pacinian corpuscule
free nerve endings
Describe the structure/function of meisenners corpuscules
found in dermis
sensitive to light touch
Describe the structure/function of Pacinian corpuscules
found in dermis
sensitive to pressure and vibrations
describe the structure and function of free nerve endings
found in BOTH epidermis and dermis
sensitive to pain, itch and temperature
what are the functions of each layer of the epidermis?
Basale- mitosis Spinosum- increase in tight cell junctions Granulosum- lipids and waterproofing Lucidium- increase in keratin production Corneum- corneocytes filled with keratin
what is the function of the hypodermis?
Subcutaneous fat storage- adipose tissue
