Skin Flashcards
Define skin.
The largest organ in the body made of epithelium, connective, muscle and nerve tissues. It has its own nerve and blood supply.
Name 6 functions of skin.
Epidermis prevents water loss. Dermis reduces risk of external injury, permits body cooling, maintains the epidermis by blood flow Immune surveillance UV protection Energy storage Sensory information
What are the 2 layers of skin?
Epidermis which forms boundaries between internal and external compartments.
Dermis which is made of connective tissue and used for structural strength.
What is the hypodermis?
It isn’t part of the skin but is anchored to it and made of adipose tissue.
What is the epidermis epithelium structure?
Stratified squamous epithelium
What are the layers of the skin?
Stratum corneum Stratum lucidum Stratum granulosum Stratum spinosum Stratum basale Dermis
Define keratinisation.
Organic process of keratin being deposited in the cells.
Define the two layers of dermis.
Papillary - protective against pathogens, blood vessels for thermoregulation and nerve endings for sense organs
Reticular - collagen bundles in three planes, made of elastic fibres which is often lost in old age
How are cells kept waterproof?
By keratin filling intracellular spaces with lipid cement.
What can skin colour be determined by?
Blood, carotene and melanin.
Define hair.
Thermoregulatory but not in humans. Derived from the epithelial layer.
Where do hair follicles come from?
Epidermis in utero. Downgrowth of epithelial cells which invade blood vessels causing hair growth.
What is the function of the arrector pili muscle.
Hair straightens when the muscle contracts.
Define sebaceous glands.
Found between follicle and pili and secrete sebum.
Name 3 types of skin glands.
Sebaceous
Apocrine - axilla, protein rich
Eccrine - thermoregulation
