Test 146  (Ocular physiology)
1. The following are true about the lens:
a. it has a higher concentration of sodium than potassium

b. it has the highest concentration of protein than other 
    organs in the body

c. 90% of proteins in the lens are water-soluble

d. gluthatione is reduced in cataract

e. gluthatione in the lens is 10 times than of the aqueous

2. The felderstrukter fibres of the extraocular muscles:

a. form the bulk of the orbital part of the muscle

b. have poorly developed sarcoplasmic reticulum

c. are singly innervated

d. are more richly supplied by blood than the 
    fibrillenstrukter fibres

e. respond to succinylcholine with a prolonged tonic

3. The following are true about rods in darkness:

a. there is tonic release of neurotransmitters

b. the sodium ion channels are open

c. the potassium ion channels are shut

d. there is a net influx of sodium ions

e. the cyclic GMP level is low in the rods

4. When a photon strikes the rhodopsin:

a. bleaching occurs

b. retinal molecules are bound to rhodopsin

c. the intracellular cGMP is increased

d. the sodium ion channels are closed

e. neurotransmitter release by rods decreases.

5. A lesion in the right medial longitudinal fasciculus:
a. causes left abduction nystagmus

b. impairs right adduction

c. impairs left adduction

d. causes problem with upgaze

e. causes problem with convergence

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