Lecture Two - Skin Flashcards
Skin accessory structures
- hair
- sweat glands
- receptors
- nails
Where is hair found
All over the body except palms, soles and lips
What is hair made of?
Made of dead, keratinised cells produced inside a hair follicle
- hair shafts projects from the follicle
Accessory structures - hair
- arrector pili muscle
- root hair plexus
- sebaceous glands
What does the arrector pili muscle do?
- contraction produces ‘goose bumps’
- improves insulation
What is the root hair plexus and what does it do?
- a collection of sensory nerves at the base of each hair follicle
- heightened sensation
What do the sebaceous glands do?
- produce oily secretion called sebum
- nourished hair shaft and naturally moisturises skin
- water repellent
- blocked hair follicles + infecutoion due to increase sebum production leads to acne
What does increased sebum production do
- results in blocked hair follicles and infection leading to acne
What is lanolin?
- sheep sebum
- purified and used commercially in skin care products
Where are eccrine sweat glands found?
- found in most areas of the skin
What do eccrine sweat glands do?
- pour watery secretions directly onto the skin surface
- important in thermoregulation and excretion
- some antibacterial action
Where are apocrine sweat glands found?
- found in specific areas
E.g: armpit, groun and around nipples
What do apocrine sweat glands do?
- secrete sticky/oily and at times potentially odorous secretions into the base of the hair follicle
- influences by hormones e.g lactation
Receptors
- tactile
- lamellar
- bulbous
What do nails do?
- protect fingertips / toes
- enhance sensation
- sensory receptors require deformation
Who is more susceptible to vitamin D dificiency ?
Highly pigmented people are more susceptible to vitamin D deficiency, particularly at extreme latitudes
The thickness of melanoma highly correlates with mortality rate
