Layers of Skin Flashcards
What are the three general layers of skin?
The epidermis, the dermis, and the hypodermis
What five layers comprise the epidermis?
From interior to exterior: stratum basale, stratum spinosum, stratum granulosum, stratum lucidum, and the stratum corneum
What constitutes the stratum basale?
The stratum basale is composed of rapidly-dividing keratinocytes as well as melanocytes
Which cells contribute to skin color, and how to they determine how dark it is?
Melanocytes found within the stratum basale determine skin color through how much melanin they produce. The number of melanocytes is relativey constant across races.
What gives the stratum spinosum its name? What other kinds of cells does it contain?
The desmosomes connecting dehydrated keratinocytes give rise to star like projections. This layer also contains Langerhan’s cells, dendritic cells that engage in antigen presentation.
What does the stratum granulosum contain? What is its function?
The keratinocytes of the stratum granulosum have many granules housing “keratin-handling” proteins. Additionally, they release lamellar bodies that form the lipid layer, giving skin its waterproof attribute.
How are the stratum lucidum and the stratum corneum similar? How are they different?
Both are comprised of dead keratinocytes that have lost their nuclei, granules, and other organelles. However, such cells in the stratum corneum are flat and stacked. They continually slough off.
How are the layers of the dermis similar? How are they different?
While both are comprised of connective tissue, the papillary dermis contains thin, loose connective tissue to allow for movement while the reticular dermis contains thicker, more dense connective tissue for anchoring things down.
What can be found in the papillary dermis?
The papillary dermis houses blood vessels/capillaries, to diffuse nutrients and oxygen both upwards and downards. Additionally, it has nerve endings for touch and pain.
What would one find in the reticular dermis?
The reticular dermis contains exocrine glands (sweat, etc) as well as hair follicles supported by erector pili muscles.
What is the hypodermis made of? What are its two functions?
The hypodermis is made of subcutaneous fat. Its functions include absorbing shock and insulating tissue.
