a muscle of facial expression and assists mastication by working with the
tongue to keep food on the occlusive surfaces of the teeth.
315.The answer is d.(Moore and Dalley, pp 1129–1130.)The umbo
(answer a)is where the tip of the manubrium of the malleus is attached to
the tympanic membrane (answer b)and would notbe a site of insertion of
a pressure equalization tube; thus both answers a and b are wrong. The
pars flaccida (answer c)of the tympanic membrane is near the course of
the chorda tympani nerve which is therefore a dangerous location for inci-
sions to place tubes. It would be difficult to place a tube within the
eustachian tube (answer e),even though that is the site of the malfunction.
316.The answer is a.(Moore and Dalley, pp 964–966, 1136–1137.)The
ciliary ganglion receives preganglionic parasympathetic nerves from the
Edinger-Westphal nucleus (cranial nerve III) that synapse in the ciliary
ganglion. Those collections of postganglionic parasympathetic nerve cell
bodies innervate the sphincter pupillae muscles, which constrict the pupil,
closing it during bright-light conditions. The geniculate ganglion (answer
b)houses the pseudounipolar cell bodies that receive taste information
from the presulcal (anterior 2/3) of the tongue. The otic ganglia (answer c)
is a parasympathetic ganglia that contains postganglionic parasympathetic
nerves to stimulate the parotid salivary gland (preganglionic fibers from cra-
nial nerve IX). The pterygopalatine (sphenopalatine) ganglion (answer d)
contains postganglionic parasympathetic nerves to stimulate the lacrimal
gland and glands of the nose and paranasal sinuses (preganglionic parasympa-
thetic fibers from cranial nerve VII). The semilunar (trigeminal) ganglion
(answer e)contains pseudounipolar cell bodies that receive pain, touch and
temperature information from the face via the trigeminal nerve. The sub-
mandibular ganglion (answer f)contains postganglionic parasympathetic
nerves to stimulate the submandibular and sublingual salivary glands
(preganglionic parasympathetic fibers from cranial nerve VII).
317.The answer is b.(Moore and Dalley, pp 526–527, 925, 967, 1142.)
You order a head CT with specific imaging of cranial nerves VI. One of the
consequences of a spinal tap can be continued leaking of cerebral spinal
fluid (CSF) at the site of the tap since the meninges have been compro-
mised. (If CSF continues to leak then autologous blood is injected at the
452 Anatomy, Histology, and Cell Biology