C5 8-13

Question 1

6 functions of the skin

Answer 1

Protection, temperature regulation, cutaneous sensation, metabolic functions, blood reservoir, excretion

Question 2

Describe the functional relationship of arrector pili muscles to the hair follicles and the evolutionary significance of these muscles in humans.

Answer 2

Each hair follicle is associated with a muscle called arrector pili. When these muscles contract they pull the hair upright. Animals with significant amounts of hair use these to look larger and trap warm air in their fur. In humans, arrector pili are mostly vestigial, but do have a small function in forcing sebum out of hair follicles.

Question 3

Apocrine sweat gland

Answer 3

FOUND IN: dermis, axillary/anogenital areas, less numerous type of sweat gland; SECRETE: water, salts, vit C, metabolic wastes, dermicidin (microbe killing peptide), proteins, fatty acids (more viscous than eccrine) ALSO: vaporizes less readily than eccrine

Question 4

Eccrine glands

Answer 4

FOUND IN: dermis, all over body, abundant on the palms, soles of feet and the forehead SECRETE: water, salts, vit C, metabolic wastes, dermicidin (microbe killing peptide) ALSO: vaporizes more readily than apocrine, very good for cooling

Question 5

3rd degree burn

Answer 5

A burn that involves the entire thickness of the skin; also called full thickness burn (epidermis and dermis)

Question 6

1st degree burn

Answer 6

A burn in which only the epidermis is damaged

Question 7

Pore

Answer 7

The surface opening of the duct of a sweat gland

Question 8

Malignant

Answer 8

Life threatening; pertains to neoplasms that spread and lead to death, such as cancer

Question 9

2nd degree burn

Answer 9

A burn in wich the epidermis and the upper region of the dermis are damaged

Question 10

Arrector pilli

Answer 10

Tiny, smooth muscles attached to hair follicles; contraction causes the hair to stand upright

Question 11

Rule of nines

Answer 11

Method of computing the extent of burns by dividing the body into a number of areas, each accounting for 9%

Question 12

Sudoriferous gland

Answer 12

Epidermal gland that produces sweat

Question 13

Hypodermis

Answer 13

SC tissue just deep to the skin; consists of adipose plus some areolar ct

Question 14

Sweat facts

Answer 14

Has a 4-6 ph acid mantle which keeps bacteria from growing on skin. Controlled by sympathetic nervous system. Distributed over entire skin surface.

Question 15

Skin function: Protection

Answer 15

Chemical barriers, physical/mechanical barriers/biological barriers

Question 16

Skin function: Temperature regulation

Answer 16

Sweat cools, vasodilation/vasoconstriction, protects body from temp variation

Question 17

Skin function: Cutaneous sensation

Answer 17

Detection of touch, pressure, pain, temp. Protects by being able to respond to harmful stimuli.

Question 18

Skin function: Metabolic function

Answer 18

Sythesizes vitamin D, produces melanin and keratin, stores lipids

Question 19

Skin function: Blood reservoir

Answer 19

Can store 5% of the body’s blood volume when it is not needed (like during exercise)

Question 20

Skin function: Excretion

Answer 20

The body eliminates limited amounts of nitrogen-containing wastes in sweat. Salts and water also get sweated out.

Question 21

Skin function: Protection: Chemical Barriers

Answer 21

Acid mantle: Low ph of skin secretions (sweat/lactic +fatty acids/epithleal cells) creates an acid mantle which is anti-fungal/antibacterial. Human defensin: skin cells also secrete natural antibiotics. Cathelicidins: antimicrobial peptides secreted by neutrophils/macrophages when skin is injured.

Question 22

Skin function: Protection: Physical/mechanical barriers

Answer 22

Multiple layers resist abrasion, ect.

Question 23

Skin function: Protection: biological barriers

Answer 23

immune system cells respond to antigens: Dermal macrophages dispose of viruses and bacteria. Langerhan’s cells

Question 24

Why are burns life threatening?

Answer 24

Immediate threat: loss of body fluids containing proteins and electrolytes resulting in dehydration/electrolyte imbalance which can cause renal shutdown/circulatory shock. Later, infection is a danger.

Question 25

When are burns considered critical?

Answer 25

2nd degree over 25% of body, over 10% of body with 3rd degree, or 3rd degree burns of face/hands/feet

Question 26

Basal cell carcinoma?

Answer 26

Least malignant and most common, 80% of skin cancer. Stratum basale cells proliferate invading dermis/hypodermis. Most often on high sun exposure areas (face). Slow growing, rarely metastasizes.

Question 27

Squamous cell carcinoma?

Answer 27

Second most common, happens in areas of sun-exposed skin. Happens in keratinocytes.

Question 28

Malignant melanoma?

Answer 28

Cancer of the melanocytes; can begin wherever there is pigment. Cancerous melanocytes grow rapidly and metastasizethrough the lyphoid system. If detected early survival chances are good. Most dangerous skin cancer.

Question 29

ABCDE for recognizing melanomas

Answer 29

Asymmetry(two sides don’t match) / Border irregularity(border has indentations) / Color(several present) / Diameter (>6mm) / Elevation

Question 30

13. Describe the interaction between sunlight and vitamin D3 synthesis.

Answer 30

When exposed to UV radiation, epidermal cells convert a steroid into vit D3.
The liver then converts D3 into an product used by the kidneys to synthesize the hormone calcitriol which is essential for the absorption of calcium and phosphorus by the small intestine.