Test 49   (ocular anatomy)

1. The following are true about the lacrimal gland tissue:

a.  the lacrimal gland is supplied by a branch of the facial artery

b. the lacrimal gland receives parasympathetic nerve supply 
    from the oculomotor nerve

c. the gland of Krause is located in the tarsus

d. the gland of Wolfring is located in the fornix

e. the histology of the lacrimal gland is similar to the salivary 
    glands

Answera.F   b.F   c.F   d.F   e.T
The lacrimal gland is supplied mainly by a branch of the ophthalmic artery.
The parasympathetic supply is derived from the facial nerve
The gland of Krause is found in the fornix whereas the gland of Wolfring is found in the tarsus.
 

2. Regarding the angle of the anterior chamber:

a. the Schwalbe's line marks the peripheral termination of the 
    Descemet's membrane

b. the trabecular meshwork is posterior to the Schwalbe's line.

c. the circular muscle of the ciliary muscle is inserted into the 
    scleral spur

d. less than 20% of the aqueous humour is drained through 
    the uveal outflow

e. the canal of Schlemm contains blood in patient with carotid 
    cavernous fistula

Answera.T   b.T   c.F   d.T   e.T
The scleral spur contains the insertion of the longitudinal muscle of the ciliary muscle.
About 10% of the aqueous humour is drained through the uveal outflow.
 

3. The tarsus:

a. contains more sebaceous glands in the upper than the lower 
    tarsus

b. the upper tarsus is more than twice the height of the lower 
     tarsus

c. has a thickness of about 1 mm

d. the upper tarsus is 5 mm longer than the lower tarsus

e. the bulbar conjunctiva is firmly adherent to the tarsus.

Answera.T   b.T   c.T   d.F   e.T
The upper tarsus measures about 11 mm in height whereas the lower tarsus 4 mm.
The tarsus is normally 1 mm in thickness.
Both the upper and lower tarsus measures about 29 mm.

4. Compared with the peripheral retinal pigment epithelium, those in the 
    macula :

a. are taller

b. are thinner

c. contain more than one layer

d. contain more melanosomes

e. contain more villi

Answera.T   b.T   c.F   d.T   e.F
The RPEs in the macular are taller, thinner, contain larger and higher number of melanosomes.
 

5. The following are true about the ocular blood flow:

a. the choriocapillaris has a lobular pattern

b. intravenous fluorescein shows up in the choriocapillaris 
    before the retinal artery

c. the choroid is supplied by the posterior ciliary artery

d. the choriocapillaris has fenestration

e. the choriocapillaris supplies nutrients to the photoreceptors

Answera.T   b.T   c.T   d.T   e.T