Iris

Question 1

what separates the lens from the iris

Answer 1

a thin layer of aqueous

Question 2

where is the pupil

Answer 2

the central (black) part of the iris

Question 3

what happens to the iris when you go outside

Answer 3

it constricts

Question 4

What is the purpose of the pupil

Answer 4

to control the amount of light entering the eye

Question 5

Is the iris constantly moving

Answer 5

yes

Question 6

What is the range of pupil diameter of the iris

Answer 6

1-9mm

Question 7

What is miosis

Answer 7

when the iris constricts

Question 8

what is mydriasis

Answer 8

when the iris dialates

Question 9

Do iris’s change throughout species

Answer 9

yes

Question 10

What is the shape of the iris

Answer 10

teardrop shaped, two leaflets

Question 11

what is the attachment of the iris to the cilliary body

Answer 11

iris root

Question 12

where is the thinnest part of the iris

Answer 12

iris root

Question 13

what is iridodialysis

Answer 13

when the iris root separates from the ciliary body

Question 14

where is the inner pupillary zone?

Answer 14

from the pupil to 1mm and 1/2 inward

Question 15

where is the peripheral/ ciliary zone?

Answer 15

from the iris root to the inner pupillary zone

Question 16

what separates the ciliary zone from the inner pupillary zone?

Answer 16

iris collarette

Question 17

why is there a division between these zones

Answer 17

muscluary changes

Question 18

where is the iris located

Answer 18

anterior to the lens

Question 19

what is the fetal pupillary membrane

Answer 19

the beginning of the vascular system for the iris

Question 20

where does the iris tissue form?

Answer 20

around the fetal pupillary membrane

Question 21

what is the iris tissue made of?

Answer 21

the leading edge of the optic cup

Question 22

where is the location of the pupillary membrane in adults

Answer 22

the collarette

Question 23

why does the leading edge of the optic cup for the iris?

Answer 23

because the fetal pupillary membrane calls it forward

Question 24

What does poor formation of the pupillary membrane of the iris cause

Answer 24

persistant pupillary membrane

Question 25

what surround the iris leaflet

Answer 25

aqueous

Question 26

what is the most anterior part of the iris

Answer 26

anterior border layer

Question 27

what is right against the anterior layer of the iris

Answer 27

a monolayer of fibroblasts

Question 28

what connects the fibroblasts in the anterior border to each other

Answer 28

gap junctions and tight junctions

Question 29

what is the point of the tight junction of the fibroblasts in the anterior border of the iris

Answer 29

for structure

Question 30

what is directly posterior to the fibroblasts of the anterior border layer

Answer 30

melanocytes

Question 31

what type of collagen in the anterior border layer of the iris

Answer 31

collagen type one

Question 32

what is in the stroma posterior to the anterior border layer

Answer 32

collagen type one

Question 33

where is the anterior border layer?

Answer 33

pupil margin to the iris root

Question 34

What are the crypts of Fuch

Answer 34

depression that are located on both side of the collarette in the anterior border layer

Question 35

what is the uveal tract

Answer 35

the iris, ciliary body and choroid

Question 36

what is trabeculae

Answer 36

the orientation of the collagen in the anterior boarder layer

Question 37

what are you looking at when you look through the cryps of Fuch

Answer 37

stroma

Question 38

what is the main type of collagen in the iris stroma?

Answer 38

collagen type one

Question 39

In the iris stroma what is the white area

Answer 39

aqueous humor fluid

Question 40

why are the tight junctions in the anterior border layer

Answer 40

to provide structure, not to act as a border

Question 41

Is everyone's iris the same?

Answer 41

no

Question 42

What type of cells are in the iris stroma

Answer 42

melanocytes, fibroblasts, melanophages (clump cells), WBCs (APCs)

Question 43

why are the blood vessels in the iris formed in a wavy pattern?

Answer 43

to allow for movement

Question 44

What are the blood vessels of the iris wrapped in, what keeps these in place

Answer 44

the vessels are wrapped in a collagen sheath. these are kept in place with collagen trabeculae in the stroma

Question 45

what is the minor circle of the iris

Answer 45

spaces where the iris doesn't have blood vessels present

Question 46

what being the pupillary membrane

Answer 46

blood vessels

Question 47

where is the fetal pupillary membrane

Answer 47

anterior to the lens

Question 48

what does the fetal pupillary membrane turn into?

Answer 48

minor circle of iris

Question 49

What is the major circle of the iris?

Answer 49

a complete anastomosing circle of blood vessels

Question 50

where is the major circle of the iris

Answer 50

in the cillary body near the iris root