Skin Flashcards
What makes the skin an organ?
The skin is an organ because it is made up of all four types of primary tissue (epithelium, connective tissue, muscle, nerve).
What is the largest organ in the body?
The skin
Name some pathologies of the skin
sunburn, acne, eczema, psoriasis, melanoma
Name the 4 primary functions of the skin
- Immune surveillance
- UV protection
- Energy storage
- Sensory function
Name the two layers of the skin
- Epidermis
2. Dermis
What is the epidermis made from?
Stratified squamous keratinising epithelial cells
How many layers are fund within the epidermis?
5 Strata (layers)
What is the main role of the epidermis?
Prevents water loss through evaporation
What is the dermis made from?
Connective tissue
What does the dermis provide?
Structural strength
How does the dermis help to maintain the epidermis?
The dermal blood flow helps to maintain the epidermis
What does the dermis permit?
Body cooling
What is the hypodermis?
The adipose layer found underneath the skin
What is the function of the hypodermis?
The hypodermis anchors skin to underlying structures
What is the main cell type found in the epidermis?
Keratinocytes
What do keratinocytes contain and why?
Keratinocytes contain keratin which is a hard substance that is resistant to abrasion
What makes the epidermis waterproof?
Keratinocytes extrude lipids in order to make the epidermis waterproof
What kind of organisation are epidermal cells in?
Stratified squamous
Aside from keratinocytes, what other cells are found in the epidermis (3)
- Melanocytes
- Langerhans cells
- Merkel Cells
Name the 5 layers of the epidermis
- Stratum corneum
- Stratum lucidum
- Stratum granulosum
- Stratum spinosum
- Stratum basale (germinativum)
What gives the stratum corneum it’s strength?
The high number of disulphide bonds
What binds the cells of the stratum corneum together?
Desmosomes
What happens in the keratinocytes of the stratum corneum?
Keratohyalin is converted into keratin.
Keratinocytes flatten out and die and get sloughed off (15-30 day turnover).
Which player of the epidermis contains high levels of keratohyalin?
stratum granulosum