Bio Term 2

Question 1

What are the main functions of the ciliary body

Answer 1

1 - to produce aqueous humour
2- to control the shape and size of lens

Question 2

What are the two main sections of the ciliary body

Answer 2

Anterior pars plicata
Posterior pars plana

Question 3

Difference between the pigmented and unpigmented epithelium in pars plicata

Answer 3

Pigmented epithelium contains melanin →allowing light to be absorbed in the eye → back box effect

Unipigmented epithelium responsible for producing aqueous humour

Question 4

what is the inner layer of the epithelia known as

Answer 4

Unpigmented epithelia

Question 5

What happens to the aqueous humour after being produced by the unpigmented epithelium

Answer 5

It gets travelled through the anterior and posterior chambers and supplies avascular lens with nutrients

Question 6

Where Is the aqueous humour drained after being utilised

Answer 6

Canal of schlemm at filtration angle

Question 7

What is the main blood supply for iris

Answer 7

Major iridium circle

Question 8

What part of the ANS is innervated by the radial dilator muscle of the iris

Answer 8

Sympathetic flight or fight response causing pupils to dilate

Question 9

What part of the ANS is innervated by the iris sphincter circular

Answer 9

Parasympathetic part causing pupils to constrict

Question 10

What is the dilator muscle innervated by

Answer 10

Innervated by the superior cervical ganglion - spinal cord

Question 11

What is the iris sphincter innervated by

Answer 11

By midbrain EDINGER-westphal nucleus which travels down the ciliary ganglion

Question 12

Effect of severing right oculomotor nerve CNIII

Answer 12

This would cause a visual pathway error in the right efferent section, resulting a lack of constriction in the right pupil during pupillary light reflex

Question 13

X

Question 14

What are the functions of the RPE

Answer 14

1.) Absorbs stray light not absorbed by the photoreceptors

2.) destroys the photoreceptors via phagocytosis

3.) acts as a blood retinal barrier to control the substances which enter and exit the choriocapillaris/RPE

4.) Storage of vitamin A - pivotal visual pigment renewal

Question 15

What is the interphotoreceptor matrix

Answer 15

Occupies Fluid filled spaces acting like glue between RPE and the photoreceptors - important in maintaining cytoskeleton organisation and preventing retinal degeneration

Question 16

Retinal glial cells

Answer 16

Muller cells what makes up the bulk of retina - wrap itself around the ganglion cells throughout retina - similar to myelin wrapping itself worked axons

Question 17

Function of Muller cells

Answer 17

1.) electrical insulation
2.) space fillers
3.) regeneration of cone visual pigments
4.) glycogen - nutrient hub
5.) electrophysiological function

Question 18

Where does the outer retina receive its blood supply from

Answer 18

Nutrients from choroicapillaris

Question 19

Where do inner 5 layers of retina receive its blood supply from

Answer 19

From the central retinal artery

Question 20

Explain the blood supply of the retina from the central retinal artery

Answer 20

As the central retinal artery reaches the surface area of the optic disc - divides into four providing the superior, inferior nasal and temporal quadrants..

Question 21

How can the retina blood vessels be seen clearly

Answer 21

Fluoroscein angiogram - veins will be seen with the bright fluorescein - analysing the health

Question 22

Under a fundus which blood vessels appear larger - veins or arteries?

Answer 22

Veins are darker under the fundus because of the thinner walls - appears more red
Also deoxygenated blood tends to be more darker