Retina Flashcards

Explore retinal anatomy, including its cellular layers, photoreceptors, macula, fovea, blood supply, visual pathways, and clinical landmarks.

Card 1 of 30Question

What is the retina?

The innermost, light-sensitive neural tunic of the eyeball that converts light into electrical signals.

In This Section

1. What is the retina?

The innermost, light-sensitive neural tunic of the eyeball that converts light into electrical signals.

2. From which embryonic structure does the retina develop?

The optic cup, a derivative of the diencephalic neuroectoderm.

3. What are the two principal components of the retina?

The neural retina and the retinal pigment epithelium.

4. Where is the retinal pigment epithelium located?

Between the neural retina and Bruch's membrane of the choroid.

5. What is a major function of the retinal pigment epithelium?

It phagocytoses shed photoreceptor outer segments and supports the visual pigment cycle.

6. How many histological layers are traditionally recognized in the retina?

Ten layers, including the retinal pigment epithelium and nine layers of the neural retina.

7. What are the ten retinal layers from outermost to innermost?

Pigment epithelium, photoreceptor layer, external limiting membrane, outer nuclear, outer plexiform, inner nuclear, inner plexiform, ganglion cell, nerve fiber, and internal limiting membrane.

8. Which retinal layer contains the nuclei of rods and cones?

The outer nuclear layer.

9. Which retinal layer contains the nuclei of bipolar, horizontal, amacrine, and Müller cells?

The inner nuclear layer.

10. What is the function of the outer plexiform layer?

It contains synaptic connections between photoreceptors, bipolar cells, and horizontal cells.

11. What is the function of the inner plexiform layer?

It contains synapses between bipolar cells, amacrine cells, and retinal ganglion cells.

12. Which retinal layer contains axons that converge to form the optic nerve?

The retinal nerve fiber layer.

13. What are the two principal types of retinal photoreceptors?

Rods and cones.

14. What is the primary function of rod photoreceptors?

Vision under low-light conditions, with high light sensitivity but no color discrimination.

15. What is the primary function of cone photoreceptors?

Color vision and high-acuity vision under relatively bright illumination.

16. What visual pigment is found in rod photoreceptors?

Rhodopsin.

17. What are the three functional types of cone photoreceptors?

Short-, medium-, and long-wavelength-sensitive cones, commonly called S, M, and L cones.

18. What is the macula lutea?

A specialized central retinal region responsible for detailed central vision.

19. What is the fovea centralis?

A small central depression within the macula specialized for the highest visual acuity.

20. Which photoreceptor type is present in the central foveola?

Cones exclusively, with rods absent from the central foveola.

21. Why does the fovea provide exceptionally high visual acuity?

It contains densely packed cones with minimal neural convergence and displacement of inner retinal layers.

22. What is the optic disc?

The retinal region where ganglion cell axons exit the eyeball to form the optic nerve.

23. Why does the optic disc produce a physiological blind spot?

It contains no rod or cone photoreceptors.

24. What is the ora serrata?

The serrated anterior boundary of the photosensitive neural retina, where it transitions into the nonvisual ciliary epithelium.

25. Which artery supplies most of the inner retina?

The central retinal artery, a branch of the ophthalmic artery.

26. What is the principal blood supply of the outer retina and photoreceptors?

The choriocapillaris of the choroid, supplied primarily by the posterior ciliary arteries.

27. Which vessel provides the main venous drainage of the inner retina?

The central retinal vein.

28. What is the role of Müller glial cells in the retina?

They provide structural and metabolic support while regulating extracellular ions and neurotransmitters.

29. What is retinal detachment?

Separation of the neural retina from the underlying retinal pigment epithelium.

30. What is the anatomical consequence of central retinal artery occlusion?

Acute ischemia of the inner retina, often producing sudden, severe monocular visual loss.