Skin Anatomy Flashcards
What are the 3 layers of the skin?
Epidermis
Dermis
Hypodermis
What does the hypodermis contain?
Fat and connective tissue
Anchors skin to underlying muscle
What does the dermis contain?
Nerves
Sweat glands
Lymph vessels
Blood vessels
The epidermis has multiple layers composed of developing keratinocytes - named after the protein they are filled with. What is keratin?
A strong fibrous protein
Allows keratinocytes to protect themselves for getting destroyed
What is the lowest layer of the epidermis?
Stratum basale - where keratinocytes start their life
What is the stratum basale made of?
Single layer of stem cells
Continually divide to produce new keratinocytes- migrate upwards
What epidermal layer is above the stratum basale?
Stratum spinosum
The stratum spinosum is made up of…
8-10 cell layers of keratinocytes (that can no longer divide)
Has dendritic cells - looking for invading microbes
What is the epidermal layer above the stratum spinosum?
Stratum granulosum
Describe the stratum granulosum
Where keratinocytes begin process of keratinisation - keratinocytes flatten out, get rid of intracellular structures and die
Creates the epidermal skin barrier
3-5 cell layers thick
Keratinisation leads to the development of what cell layer?
Stratum lucidum - 2-3 layers thick
Translucent, dead keratinocytes that have shed nuclei
Where is the stratum lucidum only found?
Thick skin - palms and soles of feet - areas that need extra protection
What is the uppermost layer of the epidermis?
Stratum corneum
20-30 layers
As new keratinocytes push up, older dead cells are sloughed off - skin flakes or dandruff
List the epidermal layers from top to bottom
Stratum corneum Stratum lucidum (palms and soles) Stratum granulosum Stratum spinosum Stratum basale
What defines a person’s skin colour?
The rate at which melanocytes are metabolised
The relative quantity of melanocytes
