Test 42    (Embryology)
1. The following structures are derived from the first pharyngeal arch:
a. muscle of facial expression

b. stapes

c. malleus 

d. incus

e. external auditory meatus

2. Bones in the skull that develop in membrane include:
a. frontal bone

b. body of sphenoid

c. parietal bone

d. mastoid of temporal bone

e. mandible


3. Structures that originate from neural crest cells include:
a. ciliary muscle

b. corneal stroma

c. corneal endothelium

d. choroidal melanocytes

e. optic nerve

4. With regard to the development of lens:

a. the lens is derived from the ectoderm

b. the lens placode first formed at 22 days gestation

c. the lens fibres in the embryo is produced entirely from the 
    anterior vesicle cells 

d. the lens sutures are arranged in a Y shape anteriorly and an 
    inverted Y shape posteriorly

e. Mittendorf's dot is remnant of the pupillary membrane

5. The following are true:

a. the lacrimal sac develops from the surface ectoderm

b. the lacrimal gland is derived from the mesoderm

c. the eyelids open at 5 months gestation

d. the puncta open into the eyelid after the eyelids have open

e. the orbicularis oculi is formed from the second pharyngeal 

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