Test 105   (ocular anatomy)

1. The optic nerve branches of the short posterior ciliary artery differ 
     from its branches in the choriocapillaris in the following ways: 

a. they are surrounded by pericytes, 

b. they lack fenestrations

c. they have tight junctions

d. they have more nerve supplies

e. they have more endothelium

Answera.T  b.T  c.T  d.F  e.F
The optic nerve branches of the short posterior ciliary artery are surrounded by pericytes, lack fenestrations and have tight junctions.
 

2. Regarding the vortex veins:

a. they drain the venous system of the retina

b. they drain the venous system of the choroid

c. they emerge from the sclera at the equator

d. they have extensive anastomoses

e. there are on average 6 vortex vein in each eye

Answera.F   b.T   c.F   d.F  e.T
The vortex veins drain the venous system of the choroid. They emerge from the sclera behind the equator. 
There are no anastomoses between the vortex veins.
98% of globes have 6 vortex veins.

 
3. The following structures produce the aqueous component of tear
    film:

a. lacrimal gland

b. meibomian gland

c. goblet cell

d. gland of Krause

e. gland of Wolfring

Answera.T   b.F  c.F  d.T  e.T
Lacrimal gland, glands of Wolfring and Krause produce 
the aqueous component of the tear film. The meibomian gland produces the oily component and the goblet cell the mucous component of the tear film.

4. Matching of the following are correct:

a. superior oblique muscle - longest tendon

b. inferior oblique muscle - shortest tendon

c. inferior oblique muscle - shortest muscle

d. medial rectus - largest muscle

e. lateral rectus - one anterior ciliary artery

Answera.T  b.F  c.T  d.T  e.T
Inferior oblique muscle has no tendon.

5. The following structure(s) synpase(s) in the ciliary ganglion:

a. nasociliary nerve fibres

b. parasympathetic nerve fibres from oculomotor nerve

c. sympathetic nerve fibres from the carotid plexus

d. parasympathetic nerve fibres form the facial nerve

c. abducent nerve fibres.

Answera.F  b.T  c.F  d.F  e.F
Only the parasympathetic fibres of cranial nerve III synapse in the ciliary ganglion. The fibres supply the ciliary muscle and iris sphincter.

 
 

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