Intermediate Lens Quiz

Q1. Where is the lens epithelium located?

• Beneath the posterior capsule only
• Throughout the central nucleus
• Beneath the anterior lens capsule
• On the external surface of the cornea

Q2. Where do lens epithelial cells proliferate and differentiate into new lens fibers?

• At the center of the posterior capsule
• Within the iris root
• Near the lens equator
• At the optic disc

Q3. What are lens fibers?

• Axons of retinal ganglion cells
• Smooth muscle fibers from the ciliary body
• Elongated specialized cells forming most of the lens substance
• Collagen bundles derived from sclera

Q4. Which part of the lens contains the oldest lens fibers?

• Anterior epithelium
• Lens equator
• Lens nucleus
• Ciliary zonule

Q5. Which part of the lens contains relatively newer lens fibers surrounding the nucleus?

• Optic disc
• Lens cortex
• Corneal endothelium
• Iris stroma

Q6. What happens to zonular tension when the ciliary muscle contracts for near accommodation?

• Zonular tension decreases
• The zonular fibers contract like skeletal muscle
• The zonular fibers detach normally
• Zonular tension increases markedly

Q7. What happens to the lens when the ciliary muscle relaxes for distance vision?

• It becomes flatter as zonular tension increases
• It moves posteriorly into the retina
• It becomes more spherical as zonular tension falls
• It contracts actively

Q8. Which surface of the lens is generally more strongly curved?

• Anterior surface
• Posterior surface
• Neither surface has curvature
• Both surfaces are completely flat

Q9. Which embryologic structure gives rise to the lens?

• Optic stalk
• Foregut endoderm
• Lens placode derived from surface ectoderm
• Neural crest only

Q10. What is the hyaloid artery's relationship to the developing lens?

• It becomes the permanent central artery of the adult lens
• It forms the ciliary muscle
• It becomes the lacrimal artery
• It supplies the developing lens and normally regresses