Test 63 (ocular anatomy)

1. The following are true about the eyelashes:

a. there are more eyelashes in the upper eyelids than the 
    lower eyelids

b. the glands of Zeis open into the hair follicles of the 
    eyelashes

c. the glands of Moll open into the hair follicles of the 
    eyelashes

d. erector pili muscles can be found at the root of the 
    eyelashes

e. they are replaced every 60 days

Answera.T   b.T   c.T   d.F   e.F
The eyelashes do not contain erector pili muscles.
They are replaced every 100-150 days.

2. The parasympathetic impulses reach the lacrimal gland through the 
    following nerve:

a. nervus intermedius

b. deep petrosal nerve

c. greater petrosal nerve

d. zygomaticotemporal nerve

e. superior branch of the oculomotor nerve

Answera.T   b.F   c.T    d.T   e.F
The parasympathetic impulse begins in the facial nucleus of the facial nerve --- nervus intermedius --- great petrosal nerve --- nerve of the pterygoid canal --- pterygopalatine ganglion --- maxillary nerve --- zygomatic nerve --- zygomaticotemporal nerve --- lacrimal nerve --- lacrimal gland. 

3. The canal of Schlemm:

a. lies posterior to the scleral spur

b. lies posterior to the Schwalbe's line

c. is lined by endothelium

d. is separated from the trabecular meshwork by sinus
    endothelium

e. drains into the vortex veins

Answera.F   b.T   c.T   d.T   e.F
The canal of Schlemm lies between the Schwalbe's line and the scleral spur.
It drains into the major venous circle of the vein.

4. The central retinal artery:

a. is the first branch of the ophthalmic artery

b. enters the orbit through the optic canal

c. enters the optic nerve at its intracanalicular portion

d. has a smaller diameter than the central retinal vein

e. supplies the rods and cones.

Answera.T   b.F   c.F   d.T   e.F
The central retinal artery arises from the ophthalmic artery within the orbit.
It enters the optic nerve about 12 mm behind the globe.
It supplies the inner half of the retina.

5. The following are true:

a. the volume of the anterior chamber is about 10 time
    that of the posterior chamber

b. the anterior chamber measures about 5 mm in normal 
    adult

c. the lens separates the anterior chamber from the 
    posterior chamber.

d. the anterior surface of  the iris is covered by epithelium

e. the iris is thickest near its insertion into the ciliary body

Answera.F   b.F   c.F   d.F   e.F
The anterior chamber volume is about 0.2ml whereas that of the posterior chamber is about 0.06ml. 
The iris separates the anterior from the posterior chamber.
The anterior surface of the iris is bare.
The iris is thickest at the collarette and thinnest when it is attached to the anterior surface of the ciliary body.