Integument Histo

Question 1

what cells are included in the epidermis?

Answer 1

merkel cells, langerhans cells, keratinocytes, melanocytes

Question 2

you’re sweating, but you notice the sweat doesn’t reenter your skin. what cells make sure of this?

Answer 2

keratinocytes (epidermal water barrier)

Question 3

what cells undergo keratinization and desquamation?

Answer 3

keratinocytes

Question 4

if your hemidesmosomes don’t work, which side of your stratum basale is affected?

Answer 4

basal layer

Question 5

in what layer of skin do keratin filaments assemble into tonofibrils?

Answer 5

statum spinosum (associate with desmosomes to get spiny appearance)

Question 6

in psoriasis, which skin layer is super thick?

Answer 6

status spinosum

Question 7

which skin layer is filled with keratohyaline granules? what are these granules made of?

Answer 7

stratum granulosum; tonofibrils and filaggrin (bundling protein)

Question 8

fillagrin has what function and is found in what skin layer?

Answer 8

bundling tonofibrils; found in stratum granulosum

Question 9

which skin layer has lamellar granules? what is the importance of lamellar granules?

Answer 9

stratum granulosum; they have lipids that protect against water loss

Question 10

difference between function of lamellar granules and keratinocytes relating to water?

Answer 10

lamellar granules: prevent water loss

keratinocytes: epidermal water barrier (keep water out of skin)

Question 11

which layers of skin are anuclear and have no organelles?

Answer 11

statum corneum and lucidum (cells only have keratin)

Question 12

what is a “squame” and where is it found? what makes them shed?

Answer 12

fully “cornified”/keratinized cells; desmosomes breaking down

Question 13

what kind of filaments is the cytoplasm mainly made of?

Answer 13

keratin filaments

Question 14

which pigment producing cells are neural crest derived?

Answer 14

melanin

Question 15

what cell makes pigment, where does this pigment go, what does it do there?

Answer 15

melanocytes; to keratinocytes nearby; protects nucleus

Question 16

what is epidermal-melanin unit?

Answer 16

one melanocyte and its association with a specific number of keratinocytes

Question 17

what happens to DOPA that turns it into melanin?

Answer 17

polymerization

Question 18

what differentiates melanosomes from pre-melanosomes?

Answer 18

amount of melanin

Question 19

langerhans cells develop from what precursor? fxn of langerhans cells?

Answer 19

monocytes; APCs

Question 20

exfoliation of the skin causes what?

Answer 20

desquamation

Question 21

fingertips have a lot or a little dermal-epidermal junctions?

Answer 21

a lot

Question 22

in what layer of the dermis will you find a lot of vasculature and nerve endings?

Answer 22

papillary layer

Question 23

another word for langer’s lines? where are these lines found?

Answer 23

cleavage lines; reticular layer of dermis

Question 24

two plexuses in dermal layer?

Answer 24

subpapillary and deep

Question 25

doc needs to inject insulin into a pt. which layer is he going to inject into and why?

Answer 25

hypodermis/subcutaneous layer bc extensive vasculature (1 lb of fat = 1 mile of vasculature)

Question 26

two general types of sensory receptors?

Answer 26

non-encapsulated and encapsulated receptors

Question 27

where would you find merkel cells? what do they do? what do they contain?

Answer 27

fingertips, hair follicles (they lack melanosomes); sense gentle touch; golgi-derived granules

Question 28

merkel cell carcinoma is (less/more) likely to occur than malignant melanoma and is (less/more) deadly

Answer 28

MCM less likely to occur than malignant melanoma, more deadly than malignant melanoma

Question 29

you suddenly feel cold, pain, and an itch. what is your skin feels these sensations? where are they located?

Answer 29

free nerve endings; papillary layer of dermis

Question 30

where are the receptors for light-touch or low-frequency stimuli found? are they encapsulated or not?

Answer 30

in dermal papillae; encapsulated

Question 31

where do you find meissner's corpuscles generally in the body?

Answer 31

palm, fingertips, soles of feet

Question 32

if you had a problem with your reticular dermis and hypodermis, what sensory receptor would not be working?

Answer 32

``` pacinian corpuscles (sense vibration, sustained pressure, coarse touch) *also found in CT of visceral organs, rectum, urinary bladder (produce pressure sensations when distorted) ```

Question 33

what gland produces a lipid mixture and releases it via holocrine secretion? what happens if these ducts are blocked?

Answer 33

sebaceous gland (releases sebum); acne

Question 34

what type of secretion do eccrine and apocrine sweat glands use?

Answer 34

merocrine

Question 35

myoepithelial cells are found in what glands? what do they do?

Answer 35

apocrine and eccrine; allows secretions to be secreted

Question 36

when do apocrine secretions become odorous?

Answer 36

when mixed with bacteria

Question 37

what inserts into the hair bulb and provides nutrients via capillaries?

Answer 37

dermal papilla

Question 38

what part of the hair follicle has epidermal stem cells?

Answer 38

follicular bulge

Question 39

what cells are in the hair matrix that divide and differentiate for hair growth?

Answer 39

keratinocytes

Question 40

what muscle gives you goosebumps? where is it located?

Answer 40

arrector pili muscle; midpt of hair root to papillary layer

Question 41

what is the cresent-shaped white area near the nail matrix called?

Answer 41

lunula

Question 42

what part of the nail has stem cells that divide to form keratinocytes?

Answer 42

nail matrix