Panopto 26 Intugement

Question 1

name the 4 cells of the epidermis

Answer 1

1. keratinocytes
2. Melanocytes
3. langerhans
4. merkel

Question 2

What cell in the epidermis is the most numerous?

Answer 2

keratinocytes

Question 2

cytomorphosis

Answer 2

changes in cells anatomy due to changes in cellular activity

Question 3

What’s another name for lamellar bodies?

Answer 3

Obland bodies, membrane coating granules

Question 4

When are lamellar bodies formed?

Answer 4

at the same time as keratohyalin granules are forming as well as in the same cells

Question 5

How big are lamellar bodies?

Answer 5

small (0.1-0.5um)

Question 6

are lamellar bodies membrane bound or non-membrane-bound?

Answer 6

they are membrane bound, meaning they’re secretory

Question 7

What do the granules in lamellar bodies contain?

Answer 7

lamellae or thin layers of a variety of lipids. they secrete the lamellae into the intercellular space, forming consecutive layers on the outer surface of the cell membrane (at least 2 layers)

Question 7

What else other than lamellae do lamellar bodies contain?

Answer 7

enzymes (breakdown of desmosomes and serine protease)

Question 8

is involucrin above or below the cell membrane

Answer 8

above

Question 9

what kind of cells are in the stratum basale?

Answer 9

basal cells that are actively dividing and theres an abundance of free ribosomes in the cell making protein cytokeratin

Question 10

How big is a tonofilament?

Answer 10

10nm

Question 11

what are tonofilaments made of?

Answer 11

cytokeratin

Question 12

as basal cells divide, where do they move to and from

Answer 12

move from the basement membrane and to the papillae

Question 13

does cytokeratin carry over to the stratum spinosum?

Answer 13

yes

Question 14

What are bundles of tonofilaments called?

Answer 14

tonofibrils

Question 15

What are tonofibrils bound together by?

Answer 15

Filaggrin, the cytokeratin binding protein

Question 16

What do tonofilaments and tonofibrils do?

Answer 16

They insert into desmosomes (bind cells together) and hemidesmosomes (bind the epidermis to the dermis by the way of the basement membrane). Multiple attachments (desmosomes and hemidesmosomes) counter the effect of friction on our skin

Question 17

are cells more acidophilic in the stratum basale or stratum spinosum

Answer 17

stratum spinosum due to the increasing amount of cytokeratin

Question 18

what does the stratum granulosum shift from?

Answer 18

the synthesis of cytokeratin to keratohyalin and lamellar bodies

Question 19

what color are keratohyalin granules? what causes it?

Answer 19

dark blue due to negative charges of phosphates and RNA

Question 20

how big are keratohyaline granules

Answer 20

1-5 micrometers (um) at their largest its the size of a RBC

Question 21

Are keratohyaline granules membrane bound?

Answer 21

non membrane bound meaning the don’t leave the cell and are not secretory

Question 22

composition of keratohyalin granules

Answer 22

filaggrin, phosphate, rich proteins, RNA

Question 23

what are these keratohyalin granules known for being like

Answer 23

a black hole. They are reactive with surrounding tonofilaments and tonofibrils (they get sucked into these granules) incorporating cytokeratin filaments

Question 24

what + what=eleiden

Answer 24

keratohyalin + cytokeratin

Question 25

in the stratum lucidum is there keratohyalin or basophilia, what happens to the cytoplasm

Answer 25

no keratohyalin or basophilia the cytoplasm is more transparent and acidophilic

Question 25

at what layer of the epidermis is keratin formed

Answer 25

stratum corneum

Question 26

what two proteins are deposited on the surface of the cell membrane in the stratum granulosum?

Answer 26

loricrin and involucrin 2 insoluble proteins on the intercellular surface of the cell membrane

Question 27

What does the physical barrier in the cell membrane do?

Answer 27

separates the internal (living cells in a watery environment) from the external (dry, surrounded by dead cells from the stratum lucidum and stratum corneum)

Question 28

What enhances the water resistance of the physical barrier?

Answer 28

adding insoluble proteins on the inside of cells and adding layers of lipid on the outside of cells, which enhances the water resistance of this barrier

Question 29

Where is the inactive enzyme serine protease found?

Answer 29

in the space between the cells in the stratum granulosum

Question 30

why is serine protease inactive?

Answer 30

the ph of the Stratum Granulosum is neutral; as the cells move more into the stratum lucidum and then the stratum corneum, the ph gradually falls once it hits 4.5, which is the surface of the stratum corneum, where the enzyme activates

Question 31

what is the target of serine protease?

Answer 31

desmosomal proteins, this allows for the dead skin cells to separate from the stratum corneum and then epidermis maintains the same thickness . Balances the new cells in the stratum basale with the loss of cells from the corneum.