OPT114 Ocular AP: Iris UPDATED
ACTUAL Questions and CORRECT
Answers
Anatomical terms
Identify the following: iris root, pupillary margin, collarette, crypts - CORRECT
ANSWER - iris root: inserted in angle of anterior chamber and merges with trabecular
meshwork and anterior portion of ciliary body
pupillary margin: also known as free edge, rests on crystalline lens
collarette: 1.5 mm from pupillary margin, divides iris into pupillary zone and ciliary zone
crypts: remnants of fetal blood vessels, look like holes. Fuch's crypts located in near collarette,
peripheral crypts located near the root
Which surface of the iris can you find circular contraction furrows and radial streaks found?
Which zone can you find them in? - CORRECT ANSWER - Circular contraction furrows
found in both anterior and posterior surface. Found in ciliary zone.
Radial Streaks found in anterior surface only. Located in ciliary zone
What causes circular contraction furrows? - CORRECT ANSWER - folding of the iris
when the pupil dilates
What is the change in appearance for the radial streaks when the pupil is constricted v dilated? -
CORRECT ANSWER - When constricted- straight
When dilated- wavy
, Which surface of the iris can you find the radial contraction furrows and structural folds of
Schwalbe? What zone of the iris is each one found in? - CORRECT ANSWER - Posterior
Surface for both
radial contraction furrows found in pupillary zone
structural folds found in ciliary zone
How are the radial contraction furrows and structural folds of Schwalbe formed? - CORRECT
ANSWER - Both formed due to the variation in thickness of iris tissues
How many layers are there in the iris and what are they called? - CORRECT ANSWER -3
layers
From most anterior-->posterior
1) stroma
2) anterior pigmented epithelium
3) posterior pigmented epithelium
What type of tissue is the stroma of the iris made out of? What three compositions make up this
tissue and what are their primary functions? - CORRECT ANSWER - Loose connective
tissue composed of collagen fibrils, fibroblasts, and ground substance
1) collagen fibrils- arranged in radial columns, they anchor blood vessels in place and protect
arteries from kinking and compressing during iris movement
2) fibroblasts- concentrated in the most anterior portion of the stroma, these cells produce,
secrete, and remodel collage fibrils and ground substance
3) ground substance- GAGs, proteoglycans, glycoproteins (Help cells talk to one another and
provide pathways for communication)
ACTUAL Questions and CORRECT
Answers
Anatomical terms
Identify the following: iris root, pupillary margin, collarette, crypts - CORRECT
ANSWER - iris root: inserted in angle of anterior chamber and merges with trabecular
meshwork and anterior portion of ciliary body
pupillary margin: also known as free edge, rests on crystalline lens
collarette: 1.5 mm from pupillary margin, divides iris into pupillary zone and ciliary zone
crypts: remnants of fetal blood vessels, look like holes. Fuch's crypts located in near collarette,
peripheral crypts located near the root
Which surface of the iris can you find circular contraction furrows and radial streaks found?
Which zone can you find them in? - CORRECT ANSWER - Circular contraction furrows
found in both anterior and posterior surface. Found in ciliary zone.
Radial Streaks found in anterior surface only. Located in ciliary zone
What causes circular contraction furrows? - CORRECT ANSWER - folding of the iris
when the pupil dilates
What is the change in appearance for the radial streaks when the pupil is constricted v dilated? -
CORRECT ANSWER - When constricted- straight
When dilated- wavy
, Which surface of the iris can you find the radial contraction furrows and structural folds of
Schwalbe? What zone of the iris is each one found in? - CORRECT ANSWER - Posterior
Surface for both
radial contraction furrows found in pupillary zone
structural folds found in ciliary zone
How are the radial contraction furrows and structural folds of Schwalbe formed? - CORRECT
ANSWER - Both formed due to the variation in thickness of iris tissues
How many layers are there in the iris and what are they called? - CORRECT ANSWER -3
layers
From most anterior-->posterior
1) stroma
2) anterior pigmented epithelium
3) posterior pigmented epithelium
What type of tissue is the stroma of the iris made out of? What three compositions make up this
tissue and what are their primary functions? - CORRECT ANSWER - Loose connective
tissue composed of collagen fibrils, fibroblasts, and ground substance
1) collagen fibrils- arranged in radial columns, they anchor blood vessels in place and protect
arteries from kinking and compressing during iris movement
2) fibroblasts- concentrated in the most anterior portion of the stroma, these cells produce,
secrete, and remodel collage fibrils and ground substance
3) ground substance- GAGs, proteoglycans, glycoproteins (Help cells talk to one another and
provide pathways for communication)
