Lecture 2 Flashcards
Where is hair not found on the body?
- palms
- soles of feet and palms
- lips
What is hair made of?
Dead keratinised cells
What does the arrest or pili muscle do?
- contracts to produce goosebumps ( improve insulation)
What is the root hair plexus?
- collection of sensory nerves at the base of each hair follicle
What is the role of sebaceous glands in the hair shaft?
Produces oily secretion called sebum which nourishes the hair shaft and moisterises skin
What acts as a waterproofing mechanism in hair follicles?
Sebum
What can acne be caused by?
Blocked hair follicles and infection due to increased sebum production
Name the two types of sweat glands:
- Eccrine
- Apocrine
Where are eccrine sweat glands found?
Most areas of the skin
What is the role of eccrine sweat glands? (4)
- pour watery secretions directly onto skin surface
- important in thermoregulation
- important in excretion
- has some antibacterial action
Where are apocrine sweat glands found?
- armpit
- groin
- around nipples
what do apocrine sweat glands do?
- secrete sticky/oily, potentially onerous secretions into base of hair follicles
- influenced by hormones
What is the role of nails?
Protect the fingertips and toes and enhance sensation
Why does the epidermis get thinner as we age?
- not dividing as accurately/ being replenished as efficiently
Why does the dermis sag and wrinkle with aging?
Due to collagen being produced slower/ less
Other than thinning and wrinkles- what else happens to the skin as we age?
- slower healing from injury
- drier ( less sebum)
- impared cooling ( less sweat)
- less pigmentation
What are the effects of tobacco smoke on skin?
- Accelerate aging by damaging collagen and elastin in the skin
- linked to poor wound healing
- acne
- linked with skin and oral cancers
What does the melanin pigment do in skin?
Absorbs UV light and protects cells from uv damage
What are the effects of nicotine on skin?
- reduced blood circulation in dermis
Other effect of vaping on skin?
Contact dermatitis
Where is melanin pigment produced?
In melanocytes
What is the name of the transport vesicles for melanin?
Melanosomes
Where are melanocytes found?
Stratum basale
Where are melanosomes found?
Throughout epidermis ( shed with keratinocytes)
What is a mole?
Cluster of melanocytes that can be caused by sun exposure
What is a freckle?
Melanocytes overproduces melanosomes that can be triggered by sun exposure
In what populations does skin pigmentation match UV exposure?
Indigenous
What is vitamin D important for?
Calcium metabolism
What can vitamin D deficiency cause?
- rickets
- negatively affected mood
What is required for vitamin D synthesis?
UV exposure
What demographic is more susceptible to vitamin D deficiency?
Higher pigmented people at extreme latitudes
Why are darker skinned people more susceptible to vitamin D deficiency?
It is harder for light to penetrate so more intensity is needed to deliver enough vitamin C
Why does NZ have one of the highest rates of skin cancer worldwide?
Large proportion of pakeha (74%) and intense UV exposure
Describe the key details of basal cell carcinomas: ( common?, dangerous?, originator point?, matastisis?, cause?, risk factor?)
- common but relatively benign
- originates in the stratum basale
- metastasis is rare
- can be caused by chronic UV exposure
- thickness correlates with mortality rate
What are tattoos?
Artificial pigmentation deposited deep within the skin in the dermal layer so it is not shed.
What is a risk of tattoos?
Pigment can spread to lymph nodes and present similarly to melanoma
What is pain during tattooing caused by?
Dermal layer containing pain receptors and free nerve ending
