W33/L7: Skin histology Flashcards
What are the 3 main layers of the skin?
Epidermis
Dermis
Subcutaneous/hypodermis
What are the 4 layers of the epidermis?
Basal layer
Stratum spinosum
Stratum granulosum
Stratum corneum
What do the keratinocytes of the basal layer look like?
Cuboidal or low columnar
What doe the keratinocytes of the stratum spinosum look like?
More diamond shaped with intracellular bridges between them (the spines)
What do the keratinocytes of the stratum granulosum look like?
The cells begin to form granules of keratin and other substances which are visible
What are the non-keratinocyte cells of the epidermis?
Melanocytes
Langerhan cells
Merkel cells
What do the melanocytes look like?
They have a clear area around the nucleus
Which cells hold the melanin and where?
The keratinocytes - it often forms a cluster over the nucleus to protect it from DNA damage
T/F: people with dark skin have more melanocytes?
F - they just make more melanin
What are the DC-like cells of the skin?
Langerhans cells
What are the two layers of the dermis?
Papillary = superficial Reticular = deep
What’s the name of the bits of epidermis that bulge downwards?
Rete ridges
What’s the name of the bits of dermis that bulge upwards?
Dermal papilla
What’s different in “thick” skin and why?
The epidermis & keratin is much thicker for mechanical protection
No hair follicles
