IS: Skin Accomplishes 5 Functions

Question 1

What are the variety of functions(6)?

Answer 1

1. protections
2. body temperature regulation
3. cutaneous sensation
4. metabolic functions
5. blood reservoir
6. excretion

Question 2

The skin constitutes for at least […] types of barriers: […], […], and […]

Answer 2

3; physical, chemical; biological

Question 3

What do chemical barriers include?

Answer 3

1. skin secretions

2. melanin

Question 4

What is the acid mantle?

Answer 4

the chemical barrier aspect of the skin– the low pH of skin secretions retards bacteria’s multiplication

Question 5

What are the secretions that supply the acid mantle ?

Answer 5

1. dermcidin (sweat)
2. bactericidal
3. defensins
   * *4. cathelicidins

**only in wounds

Question 6

Defensins:

Answer 6

skins natural secretion of antibiotics that destroy bacteria

Question 7

Wounded skin releases large quantities of protective […] called […] effective in preventing infection by group A […].

Answer 7

peptides; cathlicidins; streptococcus bacteria

Question 8

Melanin acts like a chemical barrier by…

Answer 8

protecting nucleus from UV damage

Question 9

The hardness of the skins […] cells provide physical barriers.

Answer 9

kerantinized

Question 10

What if the epidermis was thicker?

Answer 10

it would be impenetrable, we would lose suppleness and agility

Question 11

What is the section of skin that gives an outstanding physical barrier?

Answer 11

stratum corneum

Question 12

The stratum corneum layer is a physical barrier that can be compared to […] and […].

Answer 12

brick and mortar

Question 13

What parts of the stratum corneum represent the bricks and mortar analogy?

Answer 13

brick = multiple layers of dead, flat cells

mortar = glycolipids

Question 14

Epidermal […] works hand in hand with the […] and chemicals in […] to ward off […].

Answer 14

continuity; acid mantle; secretions; bacteria

Question 15

How do glycolipids in the stratum corneum act as a barrier mortar?

Answer 15

glycolipids block diffusion of water and water-soluble substances between cells

Question 16

What substances penetrate the skin?

Answer 16

1. lipid soluble substances– O2, CO2, fat soluble vitamins (A/D/E/K) and steroids (estrogens)
2. oleoresins– certain plants, such as poison ivy and poison oak
3. organic solvents– acetone, dry cleaning fluid, paint thinner (all dissolve cell lipids)
4. salts of heavy metals (Pb and Hg)
5. selected drugs– nitroglycerine and sea sick meds
6. drug agents called penetration enhancers

Question 17

Biological barriers include […] cells of the epidermis and […] of the dermis.

Answer 17

dendritic; macrophages

Question 18

Dendritic cells function:

Answer 18

trigger immune response from captured invaders that have penetrated the epidermis

*go from epidermis to lymph nodes

Question 19

Dermal macrophages function:

Answer 19

second line of defense– they dispose viruses/bacteria and trigger an immune response

Question 20

[…] produce heat within our bodies that must be released

Answer 20

internal reactions

Question 21

T/F At resting conditions, we don’t sweat.

Answer 21

false we do it’s called insensible perspiration

Question 22

What happens when the body temperature rises?

Answer 22

nervous system stimulates dermal blood vessel to dilate and sweat glands into vigorous activity

Question 23

Sensible perspiration can cause a loss of how much water?

Answer 23

3 gallons

Question 24

When the external environment is cold, […] constrict.

Answer 24

dermal blood vessels

Question 25

Cutaneous sensory receptors are classified as […] because they respond to stimuli arising […] the body.

Answer 25

exteroceptors; outside

Question 26

What are some examples for cutaneous sensory?

Answer 26

1. tactile corpuscles/tactile epithelial cells with their nerve endings allow us to become aware of a caress of the feel of our clothing against our skin
2. lamellar/pacinian corpuscles (in the deeper dermis/sub tissue) alert us to bumps or contacts involving deep pressure
3. hair follicle receptors report on wind blowing through our hair and a playful tug on a ponytail
4. free nerve endings that meander throughout the skin sense painful stimuli (irritating chemicals, extreme heat/cold, and others)

Question 27

When the sunlight touches the skin modified […] molecules are converted to a […].

Answer 27

cholesterols; vitamin D

Question 28

Epidermis makes chemical conversions that supplement those of the […].

Answer 28

liver

Question 29

Keratinocyte enzymes can:

Answer 29

1. protect– “disarm” many cancer-causing chemicals that penetrate the epidermis
2. activation– some steroid hormones
   transform cortisone applied to irritated skin into
   hydrocortisone (potent anti-inflammatory drug)

Question 30

Skin cells make several biological proteins including […], and enzyme that aids the natural turnover of […] (deters […]).

Answer 30

collagenase; collagen; wrinkles

Question 31

The […] supply is extensive and hold about […] of the body’s entire blood volume.

Answer 31

dermal vascular; 5%

Question 32

Constriction of the dermal vascular supply is when

Answer 32

organs and muscles are working vigorously

Question 33

Excretion […] limited amounts of N containing wastes in […] and in most cases […].

Answer 33

eliminates; sweat; urine