Skin Flashcards
(45 cards)
Skin functions
Sensation protection, thermoreguksgion, metabolic
What protects against UV light injury
Melanin
What part of the skin keeps water in and pathogens out
Epidermis
What is the dermis made of
CT
What type of cells is the epidermis made of
Stratified squamous
What are most of the cells in the epidermis?
Keratinocytes
Role of keratinocytes?
Form protective barrier
Where are basal keratinocytes found? What do they do?
In basal layer, give rise to new keratinocytes
Where are suprabasal keratinocytes found?
Anywhere above the basal layer, flattened, different differentiation markers
What are corneocytes?
Fully differentiated keratinocytes in cornified layer
As keratinocytes move up the skin, what do they accumulate?
Keratin
What are the key fibrous structural proteins in the epidermis
Keratin filaments
What part of the skin mitotically divides
Basil keratinocytes
What part of the skin moves up the strata
Suprabasal keratinocytes
Super Basil keratinocytes become highly organized and form what between each other
Desmosomes which are cellular junctions
What do desmosomal junctions appear as? What layer are the most easily seen in
Appear at spines and are seen in spinous layer
Corneocytes?
Fully differentiated keratinocytes that eventually shed from the surface
What is shedding from the surface of the skin called
Desquamation
Where are melanocytes found? What do the do
In the basal layer. Synthesize melanin granules
What do you Melanin granules do?
Provide pigment and photo protection (absorbs UV radiation)
What do dendritic projections do
Dispense melanin to keratinocytes
What are langerhans cells
A type of dendritic cell that is disbursed throughout the spinous layer
Where are Langerhans cells derived from? What do they do
Derived from bone marrow and they are antigen presenting cells. Because they are antigen presenting cells, they activate naïve T cells in the immune system
What does the basement membrane do?
Controls the traffic of cells and molecules between layers and structurally tethers the dermis and epidermis together
