A&P Ch 6

Question 1

functions of the skin

Answer 1

resistance to trauma and infection, barrier functions, vitamin d synthesis, sensation, thermoregulation, nonverbal communication

Question 2

resistance to trauma & infection

Answer 2

protein (keratin). intercellular junction (desmosomes). low pH (from sweat glands). bacteriocides (from sebaceous glands). dermal macrophages, leukocytes (white blood cells)

Question 3

barrier functions

Answer 3

water conservation (keep h2o from leaving). uv protection. allows transdermal drug administration (fat soluble vitamins, steroids, toxins, nicotine, testosterone, birth control, hydrocortisone, vitamin e cream.)

Question 4

sensation

Answer 4

temperature, pressure, light touch, vibration. receptors in all 3 layers of the skin

Question 5

thermoregulation

Answer 5

thermoreceptors->control center(hyp)->vasodilation/constriction & sweating (skin=effector)

Question 6

non verbal communication

Answer 6

facial expressions, acne, birthmark, scar or bad hair day

Question 7

epidermis cells

Answer 7

stem cells, keratinocytes, melanocytes, tactile cells, dendritic cells

Question 8

stem cells

Answer 8

undergo mitosis in the str. basale

Question 9

keratinocyte cells

Answer 9

most abundant cell type of the epidermis. undergo mitosis in the str. basale and spinosum. synthesize keratin, contain melanin

Question 10

melanocyte cells

Answer 10

synthesize melanin in str. basale

Question 11

tactile cells

Answer 11

receptors of touch

Question 12

dendritic cells

Answer 12

macrophages. white blood cells

Question 13

layers of the epidermis

Answer 13

basale, spinosum, granulosum, lucidum, corneum

Question 14

basale layer

Answer 14

stem cells, keratinocytes, melanocytes, tactile cells, dendritic cells

Question 15

spinosum layer

Answer 15

keratinocytes. some mitosis in deepest layer. cells held together by desmosomes. thickest layer in skin

Question 16

granulosum layer

Answer 16

keratinocytes. keratin is synthesized. lipids are secreted. keratinocytes die in the layer

Question 17

lucidum layer

Answer 17

dead keratinocytes. thin translucent layer in thick skin only.

Question 18

corneum layer

Answer 18

dead keratinocytes. thickest layer in thick skin (soles of feet & palms of hands.). strong layer of dead cells

Question 19

life history of a keratinocyte

Answer 19

born in stratum basale. live in bottom 3 layers. die in stratum granulosum. before death keratin and eleiden are made for water conservation. skeletons in stratum lucidum(in thick skin) and stratum corneum (thicker in thick skin)

Question 20

the dermis

Answer 20

consists of fibrous connective tissue. areolar and dense irregular. also contains accessory structures of the skin. blood vessels to supply nutrients and remove wastes. nerves and receptors to provide sensation. glands to secrete sweat and oils. hair follicles for warmth, social, sensory functions. varies in thickness in different body regions. dermal papillae push into dermis, resist slippage.

Question 21

dermis layers

Answer 21

papillary, reticular

Question 22

papillary layer

Answer 22

superficial, 1/5 of dermis, includes dermal papilla. composed of areolar tissue

Question 23

reticular layer

Answer 23

deep. 4/5 of the dermis. composed of dense irregular tissue. stretch marks invade this deep

Question 24

hypodermis

Answer 24

not considered part of the skin. composed of adipose and areolar tissue. site of subQ injections. protection, insulation, energy source

Question 25

pigments responsible for skin colour

Answer 25

hemoglobin(red), melanin(brown), carotene(orange), collagen(white)

Question 26

cyanosis

Answer 26

blue, due to lack of oxygen

Question 27

erythema

Answer 27

red due to increased blood flow

Question 28

pallor

Answer 28

pale due to lack of blood flow

Question 29

albinism

Answer 29

white due to genetic lack of melanin

Question 30

jaundice

Answer 30

increase in bilirubin due to decrease in liver function

Question 31

hematoma

Answer 31

bruising due to clotted blood

Question 32

friction ridges

Answer 32

finger ridges, allow for fine control

Question 33

flexion lines

Answer 33

skin attachment to underlying fascia

Question 34

freckles

Answer 34

patches of melanised skin

Question 35

moles

Answer 35

elevated freckles

Question 36

hemangiomas

Answer 36

birthmark, bening tumour of dermal capillaries

Question 37

types & distribution of hair

Answer 37

lanugo, vellus, terminal

Question 38

lanugo

Answer 38

fetus

Question 39

vellus

Answer 39

fine, unpigmented hair. all of childrens, most of womens

Question 40

terminal

Answer 40

longer, coarser, pigmented hair, cover most of males body

Question 41

structure of hair and nails

Answer 41

hair is dead except for hair matrix above the dermal papilla. pilo erector muscles raise hair with sns stimulation (hot or cold). colour is due to proportion of eumelanin(brown)ot o pheomelanin(red

Question 42

nails

Answer 42

originate from str. corneum. mitosis occurs in nail matrix, nail groove must be scrubbed well during hand washing

Question 43

ceruminous glands

Answer 43

cerumen = sebum + dead cells. waterproofing function

Question 44

mammary glands

Answer 44

breasts, present in everyone. mammary glands are modified apocrine sweat glands that develop only during pregnancy