Neruo 7.2 Central Connections of the Retina

Question 1

What are the 2 types of cells in the retina? What is the use of each?

Answer 1

Rods - night vision Cones - colour vision. 3 types: red blue green.

Question 2

What is the name of the left and right visual fields of the retina?

Answer 2

Nasal and temporal hemiretina

Question 3

What are the 3 types of interneurones in the retina?

Answer 3

bipolar, horizontal and amacrine

Question 4

How do rods and cones interact with interneurones?

Answer 4

Rods converge on one single bipolar cell Cones have a 1 cone to 1 interneuron interaction

Question 5

What is the visual pathway?

Answer 5

Eye –> optic nerve –> optic chiasm –> optic tract –> lateral geniculate nucleus –> optic radiation –> visual cortex

Question 6

What are the 2 types of ganglion cells in the retina?

Answer 6

Magnocellular and parvocellular

Question 7

Where is the lateral geniculate nucleus found?

Answer 7

thalamus

Question 8

What is the magnocellular and parvocellular pathway sensitive to?

Answer 8

Magnocellular - luminance contrast and motion Parvocellular - colour contrast, fine detail

Question 9

What is lazy eye known as medically? How is it caused?

Answer 9

amblyopia Caused by abnormal binocular input early in life e.g. strabismus, anisometropia (refractive difference between eyes), deprivation (congenital cataract, ptosis etc)

Question 10

What is strabismus, anisometropia, and deprivation/

Answer 10

strabismus - Lack of coordination of eyes anisometropia (refractive difference between eyes), deprivation (congenital cataract, ptosis etc)

Question 11

Where is the highest density of cones located in the retina?

Answer 11

Fovea

Question 12

What controls the sphincter and dilator pupillae?

Answer 12

sphincter pupillae - CN III dilator pupillae - sympathetic

Question 13

What is horners syndrome? Symptoms?

Answer 13

disruption of cervical sympathetics small pupil (miosis), partial ptosis, anhydrosis

Question 14

Question 15

What can cause a non-homonymous bitemporal hemianopia?

Answer 15

pituitary adenoma compressing optic chiasm

Question 16

What would happen if the right temporal lobe was damaged?

Answer 16

Loss of vision in superior quadrant of the left visual hemifield. Superior left homonymous quadrantanopia.

Question 17

What is macular sparing and why does it occur in damage to the visual cortex?

Answer 17

occurs due to areas of visual cortex receiving blood from calcarine and branhces of MCA, allowing macular to be spared if one artery is occluded.