3 - Uvea

Question 1

Compared to the Iris center, where is the pupil aperture actually located?

Answer 1

Slightly nasal and inferior

Question 2

What is the avg. diameter of the iris?

Answer 2

12 mm

Question 3

What region of the iris, was the attachment site for the fetal pupillary membrane during embrylogical development?

Answer 3

Collarette

Question 4

What divides the iris into the pupillary zone?

Answer 4

Collarette

Question 5

Where is the iris margin located, posterior or anterior?

Answer 5

Posterior, on the anterior of the lens.

Question 6

What part of the ciliary body is the iris attached to?

Answer 6

Anterior portion

Question 7

Where is the iris the thickest?

Answer 7

Iris Root

Question 8

True or False, The iris always divides the anterior segment of the globe into anterior and posterior chamber?

Answer 8

True

Question 9

What is Iridodialysis?

Answer 9

Tear of the Iris from the ciliary body

Note: there is severe damage to blood vessels and nerves (sector paralysis of the iris muscle)

Question 10

How many layers are there of the Iris and name them.

Answer 10

1) Anterior Border Line (ABL)
2) Stroma and Iris Sphincter Muscle
3) Anterior Epithelium and DILATOR MUSCLE
4) Posterior Epithelium

Question 11

What layer of the Iris is the Anterior Border Layer part of?

Answer 11

Stroma

Note: It is a thin condensation of the stroma, to be precise

Question 12

What is the ABL composed of ?

Hint: 2 items

Answer 12

Melanocytes(below) and Fibroblasts (surface)

Question 13

In the anterior of the Iris, there are absent oval shaped _________?

Answer 13

Iris Crypts

Question 14

What is the stroma of the Iris composed of?

Hint: There are 4 distinct types

Answer 14

Pigmented cells (melanocytes and clump cells)
Non-pigmented cells (Fibroblasts, Lymphocytes, Macrophages and Mast cells)
Collagen Fibrils
Ground Substance

Question 15

What type of cell in the stroma, actively scavenge for free pigment?

Answer 15

Clump cells

Question 16

What type of arrangement are collagen fibrils set in the iris stroma?

Answer 16

Radial

Question 17

Where is major circle of the iris located?

Answer 17

In the ciliary body to the iris root

Question 18

What vessel body is located in the iris stroma, inferior to the collarette and is remnant of embryologic development?

Answer 18

Minor circle of the iris

Question 19

Are the Iris capillaries fenestrated or not?

Answer 19

They are.

Note: They form the Blood Aqueous Barrier

Question 20

True or False. The Iris stroma and stroma of the ciliary body are continuous with one another?

Answer 20

True

Question 21

What is the sphincter muscle composed of and where is it primarily located?

Answer 21

Smooth muscle cells and in the Stroma

Question 22

When contraction of the sphincter muscle occurs, what happens to the pupil?

Answer 22

Miosis occurs

Note: Parasympathetic system at work.

Question 23

What is an Iridectomy?

Answer 23

Removal part of the iris, which is used to eleviate IOP.

Note: If the Iris Sphincter is cut, it will continue to function

Question 24

What is an iridotomy?

Answer 24

Removal of the Iris but using YAG laser

Question 25

What is the anterior iris epithelium made of?

Answer 25

Myoepithelial cell Note: Pigmented Cuboidal epithelium are joined by tight junctions and desmosomes

Question 26

What is the basal part of the anterior iris epithelium made of?

Answer 26

Contractile smooth muscle processes

Question 27

Where exactly is the dilator muscle located in the iris?

Answer 27

Iris root to a point in the stroma (below the midpoint)

Question 28

When the dilator muscle pulls the pupilary portion toward the root, what occurs to the pupil?

Answer 28

Mydriasis Note: This is a sympathetic motif

Question 29

What is the posterior iris epithelium made of?

Answer 29

Heavily pigmented columnar cells joined by tight junctions and desmosomes

Question 30

In what positional method is the anterior and posterior iris epihelial layers listed?

Answer 30

APEX to APEX

Question 31

Since both the Anterior and Posterior iris epithlium send out microvilli projections, how are they joined together?

Answer 31

Desmosomes

Question 32

What is an Iris synechiae and what can cause it to occur?

Answer 32

An attachment where the Iris and another area are connected. Usually this is caused by a traumatic blow or whiplash

Question 33

True or False. Fuch's of crypts are hole like structures that are always located on both side of the collarette?

Answer 33

True Note: The crypts are used for aqueous outflow to the stroma

Question 34

What is the main contributor of eye color?

Answer 34

Melanin granules within melanocytes

Question 35

What are other factors that contribute to iris color?

Answer 35

Wavelength Melanin granules within melanocytes Density of connective tissue

Question 36

In which areas is there heavily amount of pigmentation the most in the iris?

Answer 36

The two epithelium layers Note: In albinism, pt. will lack pigmentation in the epithelium layers

Question 37

What is dispersion syndrome?

Answer 37

pigment granules that are shed from the posterior iris surface and are dispersed into the anterior chamber. They are deposited on the iris, lens or corneal endothelium. Note: This is a serious issue in regards to angle closure and aqueous outflow

Question 38

What is heterochromia?

Answer 38

Where one iris is different color than the other.This can be congenital or due to uveal inflammation. Note: If it is congenital, then the sympathetic innervation may be suspected

Question 39

Which are of the ciliary body the thickest, nasal or temporal?

Answer 39

Temporal

Question 40

What is the termination point of the ciliary body from the posterior region?

Answer 40

At the Ora Serrata

Question 41

What are the two divisions of the ciliary body?

Answer 41

Pars Plicata and Pars Plana

Question 42

Which region contains the ciliary processes in the ciliary body?

Answer 42

Pars Plicata

Question 43

Approx. how many processes extend into the posterior chamber?

Answer 43

70 to 80 Note: the region between the ciliary processes are called the valleys of Kuhnt

Question 44

Between the pas plana and pars plicata, which one is connected to the ora serrata?

Answer 44

Pars plana Note: dentate processes are retinal projections (in between the teeth are Oral bays)