Test 181  (Ocular anatomy)

1. The following are branches of the ophthalmic nerve: 

a. zygomatic nerve

b. frontal nerve

c. nasociliary nerve

d. lacrimal nerve

e. superior alveolar nerve
 

Answera.F   b.T  c.T   d.T  e.F
Zygomatic nerve and the superior alveolar nerve are branches of the maxillary nerve.

2. A lesion of the ciliary ganglion causes:

a. loss of accommodation

b. mydriasis

c. ptosis

d. loss of corneal sensation

e. decreased lacrimation
 

Answera.T  b.T  c.F  d.F  e.F
Ciliary ganglion contains synapses of the parasympathetic fibres that supply the constrictor muscle of the iris 
and the ciliary muscle. 

 
 

3. The following structures are derived from the surface ectoderm:

a. sclera

b. lacrimal gland

c. conjunctival epithelium

d. trabecular meshwork

e. eyelashes
 

Answer
a.F   b.T  c.T  d.F  e.T
Sclera is derived from the mesoderm.
Trabecular meshwork from the mesoderm.

 

. 4. The following are true about the lacrimal gland:

a. the orbital part of the lacrimal gland is located anterior 
    to the orbital septum

b. the lacrimal gland is enclosed within a well-defined 
    capsule

c. it is a tubulo-acinar structure

d. it receives nerve fibres from the deep petrosal nerve

e. its lymphatic drainage is to the superficial parotid gland
 

Answer
a.F  b.F  c.T  d.F  e.T
The lacrimal gland is behind the orbital septum. The gland has no true capsule. The parasympathetic fibres travel through the great petrosal nerve and not the deep petrosal nerve.

5. The following are true about the oculomotor nerves within the orbit:

a. the oculomotor nerve divides into two branches before 
    it enters the orbit

b. the superior branch of the oculomotor nerve is larger 
    than the inferior branch

c. the superior branch of the oculomotor nerve supplies 
    only the superior rectus and the levator superioris

d. the superior branch of the oculomotor nerve supplies 
    the skin of the forehead

e. the inferior branch of the oculomotor nerve contains 
    parasympathetic nerve fibres
 

Answer
a.T   b.F  c.T  d.F e.T
The superior branch of the oculomotor nerve is smaller than the inferior branch. The oculomotor nerve is a motor nerve and does not contain sensory nerve.

 

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