Skin Anatomy 2

Question 1

What are the 4 accessory structures

Answer 1

Hair, sweat glands, receptors, nails

Question 2

Outline Hair

Answer 2

Found all over the body accept alms, soles, and lips
Made of dead, keratinised cells produced inside a hair follicle
Hair shaft projects from follicle
Also consists of erector pili muscle, root hair plexus, and sebaceous glands

Question 3

What part of hair is dead

Answer 3

Part projecting out of the skin/hair follicle - the hair shaft

Question 4

Outline the erector pili muscle

Answer 4

contraction produces “goose bumps”. Improves insulation. Pulls shaft upright, trapping small pocket of air - leads to bump appearance

Question 5

Outline the root hair plexus

Answer 5

Collection of sensory nerves at the base of each hair follicle. Heightened sensation

Question 6

Outline the sebaceous gland

Answer 6

Produces oily secretion called sebum. Nourishes hair shaft and naturally moisturises skin. Water repellent - property of oils. Blocked hair follicles + infection due to increased sebum production leads to acne

Question 7

What is the animal equivalent of sebum and what is it commonly used for

Answer 7

Lanolin. Sheep sebum. Purified and used commercially in skin care products

Question 8

What are the two types of sweat glands

Answer 8

Eccrine and apocrine

Question 9

Outline eccrine glands

Answer 9

Found in most areas of the skin. Pour watery secretion directly onto the skin surface. Important in thermoregulation and excretion. Some antibacterial action

Question 10

Outline apocrine sweat glands

Answer 10

Found in specific areas eg armpit, groin, and around nipples. Secrete stick/oily and at times odorous secretions into the base of the hair follicle. Influenced by hormones, eg lactation.

Question 11

Why do apocrine glands secrete into hair follicle rather than skin surface

Answer 11

Apocrine sweat glands are loaded much more deep than eccrine glands Secreting into hair follicle provides a shorter pathway than travelling all the way to the skin surface.

Question 12

3 receptor types of skin

Answer 12

Tactile, lamellar, bulbous

Question 13

3 features of nails

Answer 13

Protect fingertips/toes. Enhance sensation. Sensory receptors require deformation

Question 14

Outline skin aging.

Answer 14

Thin epidermis. Thin dermis (sagging/wrinkling) - reduced collagen. Slower skin repair. Dryer epidermis (less sebum). Impaired cooling (less sweat). Less pigmentation - pale skin, grey hair

Question 15

Outline smoking and skin aging

Answer 15

Tobacco smoke causes premature skin aging. Contains agents hat accelerate aging. Damages collagen and elastin in the skin. Linked with poor wound healing, acne, skin and oral cancers

Question 16

What about vaping on skin aging

Answer 16

Contains nicotine. Nicotine reduce blood circulation in the dermis. Contact dermatitis (skin inflammation) due to metal coating on e cigarettes

Question 17

Outline skin pigmentation, melanocytes, and melanosomes

Answer 17

Melanin pigment absorbs UV light - protects cells from UV damage
Produced in melanocytes
Transferred to epidermal cells by melanosomes - vesicles containing melanin

Question 18

Where are melanocytes located

Answer 18

Located in stratum basale

Question 19

Where are melanosomes found throughout

Answer 19

Found throughout the epidermis - shed with keratinocytes

Question 20

Outline the density of melanocytes

Answer 20

Varies throughout the body and through time

Question 21

Outline the difference between a mole and a freckle

Answer 21

Mole - cluster of melanocytes. Over-proliferation can be caused by sun exposure
Freckle - Melanocytes overproducing melanosomes. Over-production triggered by sun exposure. Can reduce with age

Question 22

Outline skin pigmentation matching UV exposure

Answer 22

Indigenous populations closer to the equator = more sun = more UV = more melanin = darker pigmentation

Question 23

Outline Vitamin D

Answer 23

Vitamin D is essential for normal calcium metabolism and strong bones. UV exposure in skin is required for vitamin D synthesis. Likely explains the greater incidence of lightly pigmented skin at higher latitudes

Question 24

What can Vitamin D deficiency cause

Answer 24

Rickets and effects mood

Question 25

Outline when pigmentation does not match UV exposure

Answer 25

Highly pigmented people are more susceptible to vitamin D deficiency, particularly at extreme latitudes.

Question 26

Outline Basal cell carcinoma

Answer 26

Common but relatively benign. Originates in stratum basale. Metastasis (spread) is rare. Stratum basale regenerative stem cell

Question 27

Outline malignant melanoma

Answer 27

Rare but deadly if not treated. Originates in melanocytes (pigmented). Highly metastatic. Mortality rate dependent upon tumour.

Question 28

Outline artificial pigmentation of tattoo

Answer 28

Artificial pigmentation deposited into the dermal layer of the skin, not shed. Captured (but not broken down) inside immune cells/scar tissue.

Question 29

What are the types of tattoos

Answer 29

Trauma, decorative, cosmetic

Question 30

Sebum is an oily secretion produced by

Answer 30

Sebaceous gland

Question 31

Melanocytes are found in the stratum basale

Answer 31

Moles are caused due to over proliferation of melanocytes

Question 32

The two types of swear glands are

Answer 32

Eccrine
Apocrine

Question 33

Vitamin D is essential for ___________ metabolism and its defficiency causes

Answer 33

Rickets

Question 34

Outline thin epidermis in terms of skin aging

Answer 34

With age, stratum basale regenerative stem cells rate of division significantly reduces. Less layers refreshed, epidermis layer becomes thinner with age

Question 35

What causes saggy/wrinkling skin

Answer 35

Reticular layer of dermis contains collagen and elastin fibres - conform strength to region. Collagen/elastin regeneration slows with age, decreased levels result in saggy/wrinkly skin. Less collagen/elastin, as well as reduced vascularity, results in thin dermis.

Question 36

What causes slower skin repair

Answer 36

Less blood flow (due to thinning of dermis). Blood carry’s nutrients/healing factors required for recovery from injury.

Question 37

What causes drier epidermis and impaired cooling

Answer 37

Less blood supply slows down sebaceous gland and sweat gland activity.
Lack of sebum results in dried out epidermis, lack of sweat gland activity results in less evaporative cooling

Question 38

Skin aging and pigmentation

Answer 38

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