Bsf Block 1: Skin

Front 1

K5 and K14 isoforms of keratin are found in what layer?

Back 1

stratum basale

Front 2

What layers comprise the stratum germinativum?

Back 2

stratum basale + basal portion of stratum spinosum

Front 3

Stratum basale is attached to the basal lamina by what?

Back 3

desmosomes and hemidesmosomes (integrin based)

Front 4

What is the thickest epidermal layer?

Back 4

stratum spinosum

Front 5

What keratin isoforms are found in the stratum spinosum?

Back 5

K1 and K10

Front 6

What are the intermediate filaments that radiate from perinuclear region and end at dense plaques for desmosomes called? where are they located?

Back 6

tonofilaments. found in the stratum spinosum (giving the cell a "spiny" appearance)

Front 7

What are the phospholipid containing granules called and where are they synthesized?

Back 7

lamellar bodies. synthesized in stratum spinosum (continue to be synthesized in stratum granulosum but are exocytosed at the apical portion of the granulosum)

Front 8

__________, a protein which makes the proteinaceous cornified layer, is synthesized at the stratum spinosum.

Back 8

involucrin

Front 9

What enzyme crosslinks involucrin to the plasmalemma?

Back 9

transglutaminase

Front 10

What is the most superficial layer in which cells still retain their nuclei (are still alive)?

Back 10

stratum granulosum

Front 11

Keratohylin granules are rich in _________ and ________.

Back 11

cysteine and fillagrin (which is rich in hystidine)

Front 12

Which protein cements keratin filaments together into aggregates, flattening keratinocytes? Where is it found?

Back 12

fillagrin. found in keratohylin granules in stratum granulosum

Front 13

Apoptosis of keratinocytes is initiated in the stratum...

Back 13

stratum granulosum

Front 14

The stratum lucidum is found only in ___________ and is the short intermediate stage between _____________.

Back 14

thick skin

found between stratum granulosum and stratum corneum

Front 15

What is desquamation?

Back 15

it's when cells near the skin surface slough off after having lost their desmosome attachments

Front 16

what kind of keratin isomers do you find in the stratum granulosum?

Back 16

K2 and K11. they are the product of the posttranslational modification of K1 and K10 keratin isoforms from the stratum spinosum

Front 17

Melanocytes are found in the stratum

Back 17

basale

Front 18

What cells produce pigments?

Back 18

melanocytes

Front 19

What is pheomelanin?

Back 19

reddish yellow pigment

Front 20

How is melanin made?

Back 20

tyrosinase converts tyrosine to DOPA, and then into melanin

Front 21

Melanocytes look like

Back 21

octopuses due to their cytoplasmic extensions

Front 22

How is melanin secreted?

Back 22

cytocrine secretion: exocytosis of melanosomes from melanocytes

Front 23

Melanin is mainly found where?

Back 23

in the stratum germinativum because it shields the DNA of actively dividing cells

Front 24

Langerhans cells are found in the stratum __________ and are _______ shaped.

Back 24

-stratum spinosum
-stellate shaped

Front 25

What are the phagocytic cells that stimulate T-lymphocytes and serve as antigen presenting cells?

Back 25

langerhans cells

Front 26

Merkel cells are _________________. They are found in the stratum ______.

Back 26

mechanoreceptor cells found in the fingers/areas sensitive to touch

stratum basale

Front 27

What are the major cells of the dermis?

Back 27

fibroblasts and macrophages

Front 28

What kind of connective tissue makes the dermis?

Back 28

irregular collagenous CT

Front 29

What is responsible for fingerprints?

Back 29

primary dermal ridges

Front 30

Projections of the epidermis into the dermis are called what?

Back 30

dermal papillae

Front 31

What is the layer deep to the basal lamina?

Back 31

papillary layer of the dermis

Front 32

What is the layer deep to the papillary layer?

Back 32

reticular layer of the dermis

Front 33

The reticular layer is always _________ than the papillary layer.

Back 33

denser/thicker

Front 34

What is the primary function of blood supply to the dermis?

Back 34

thermoregulation; not delivery of nutrients

Front 35

What blood supply plexus is located in the papillary layer (superficial)? Structure?

Back 35

subpapillary plexus. has capillary loops that extend into the dermal papillae

Front 36

What is the blood supply plexus located deep in the dermis?

Back 36

cutaneous plexus

Front 37

What extends from the cutaneous plexus to the subpapillary plexus, bringing blood?

Back 37

the AV shunt

Front 38

Vasoconstriction, caused by cold temperatures, causes the ____________ to reduce blood flow to the papillary plexus. This _________ is innervated by the sympathetic nervous system.

Back 38

AV shunt

Front 39

Meissner's corpuscles occur in the ________ and are sensitive to

Back 39

found in dermal papillae

light touch (mechanoreceptors)

Front 40

Pacinian corpuscles occur in the __________ and are sensitive to

Back 40

reticular layer

Pressure

Front 41

Ruffini's corpuscles occur _____________ and respond to

Back 41

in the deep dermis of the feet

respond to tension

Front 42

The epidermal invagination from which hair arises is called the

Back 42

hair follicle

Front 43

Epidermal cells of the __________ constantly divide and differentiate into different cells of the hair

Back 43

hair bulb

Front 44

What are the different regions of growing hair?

Back 44

i. Medulla – central (middle)
ii. Cortex – surrounds medulla
iii. Cuticle – outermost region

Front 45

What cells are responsible for hair color?

Back 45

melanocytes

Front 46

Layers of the _______________ of hair are continuous with epidermal layers of skin

Back 46

external root sheath

Front 47

Hair growth stages?

Back 47

Anagen- period of hair growth; can be several years

Catagen- brief period when growth is halted

Telogen- long rest period; ~3 months for scalp hairs, which the follicle atrophies

"ACT"

Front 48

What is the membrane called that separates the hair follice from the dermis, into which the arrector pili muscles insert?

Back 48

glassy membrane

Front 49

The sebaceous gland develops as an outgrowth of the

Back 49

external root sheath

Front 50

Sebum is a product of what gland?

Back 50

sebaceous gland

Front 51

What is sebum?

Back 51

an oily mixture of cholesterol and lipids

Front 52

What glands are involved in thermoregulation via evaporative heat loss?

Back 52

eccrine sweat glands

Front 53

Eccrine sweat glands secrete

Back 53

clear, hypotonic solution with some ions but no protein

Front 54

What gland secretes protein, lipids, ammonia in response to emotional/sensory stimulation and not heat?

Back 54

APocrine sweat glands (make you smell like an APe)

Front 55

Aging affects on skin?

Back 55

-decreased number of dermal papillae
-stratum corneum does not recover from trauma as quickly
-reduced fillagrin--scaliness
-reduced collagen and elastic fibers