Anatomy of the Skin Flashcards
What are the four accessory structures of the skin?
Hair
Sweat Glands
Receptors
Nails
Where is the hair found and what is it made of?
All over the body except palms, soles and lips
Made of dead, keratinised cells produced inside a hair follicle
Hair shaft (dead part) is projected out from the follicle (below visible surface)
What is the arrector pilli muscle?
A muscle found in the hair that contracts to produce goose bumps, it pulls on hair follicle making hair shaft stand upright and trapping tiny packets of air, increasing insulation
What is the root hair plexus?
A collections of sensory nerves found at the base of each hair follicle which heighten sensation. Nerve endings command follicle to contract or release
What are sebaceous glands?
Glands that produce oily secretion called sebum. Made of epithelial cells
What is sebum?
Sebum nourishes hair shafts and naturally moisturises skin. It is also a water repellent due to it being an oily secretion
How does acne occur?
Blocked hair follicles + infection due to increased sebum production leads to acne
What is lanolin?
Sheep sebum which can be purified and used commercially in skin care products
What are the two types of sweat glands?
Eccrine and Apocrine
What is an eccrine sweat gland?
Found in most areas of skin, pours water directly onto the skin surface, important in thermo regulation and excretion, has some antibacterial action
What is an apocrine sweat gland?
Found in specific areas e.g. armpit, groin and around nipples
Secretes sticky/oily and sometimes odorous secretions into base of hair follicle (not directly on skin surface)
Influenced by hormones e.g. lactation
What are the three times of receptors?
Tactile
Lamellar
Bulbous
Receptors allow us to pick up an array of sensations
Why are nails important in regards to skin?
Protect fingertips/toes
Enhance sensation
Sensory receptors require deformation and nails allow this in the form of temporary deformation rather than permanent
How does skin anatomy relate to its function?
Aging
Pigmentation (protection from UV radiation, vit D production)
Skin cancer/Vit D insufficiency
Tattoo (artificial pigmentation)
What are the six components of skin aging?
Thin epidermis
Thin dermis
Slower skin repair
Drier epidermis
Impaired cooling
Less pigmentation
How does a thin epidermis occur with aging?
Cells divide much slower and less frequently resulting in thinner layers of epidermis
How does a thin dermis occur with aging?
Reticular layer in dermis contains collagen and elastin. Replenished more slowly hence less collagen and elastin resulting in sagging/wrinkling
How does slow skin repair occur with aging?
Less blood flow and less nutrients results in longer repair time
How does a drier epidermis occur with aging?
Less sebum is produced due to less blood flow resulting in dry skin
How does impaired cooling occur with aging?
Sweat glands cannot produce as much sweat hence body cannot thermoregulate as quickly
How does less pigmentation occur with aging?
Melanin cells produce melanin slower due to less blood flow resulting in pale skin and grey hair
How does tobacco cause premature skin aging?
Contains agents that accelerate aging, damages collagen and elastin, linked with poor wound healing, acne, skin and oral cancer
How does vaping cause premature skin aging?
Contains nicotine which reduces blood circulation in the dermis, contact dermatitis (skin inflammation) due to metal coating on e-cigarettes
How do melanocytes and melanosomes relate to melanin?
Melanin is produced in melanocytes which are transferred around skin in vacuoles by melanosomes
Melanin pigment absorbs UV light protecting cells from UV damage
