along with CN IV, V 1 , and VI. Neither glaucoma (answer d)nor parotid
gland tumor (answer e)would present with those symptoms.
320.Answer is c.(Moore and Dalley, pp 1130, 1139.)You suspect a tumor
is blocking left foramen ovale. The mandibular division of the trigeminal
cranial nerve exits the skull through the foramen ovale. This division pro-
vides general sensation to the tongue (via the lingual nerve) and mandibu-
lar teeth (via the inferior alveolar nerve) and area over the mandible (via the
buccal nerve). In addition the mandibular division of the trigeminal also
innervates 8 muscles (the four muscles of mastication [temporalis, masseter,
medial and lateral pterygoid muscles], two associated with the floor of the
mouth [the mylohyoid and anterior belly of the digastric muscles] and two
tensors [tensor tympani in the middle ear and tensor palati in the soft
palate]). In addition preganglionic nerves from cranial nerve IX (via the
lesser petrosal nerve) also pass through the foramen ovale on their way to
stimulate the parotid salivary gland. A tumor at the superior orbital fissure
(answer a)would affect eye movements and forehead sensation. A tumor at
the foramen rotundum (answer b)would affect sensation under the eye on
the face and maxillary teeth pain. A tumor at the internal acoustic meatus
(answers d and e)would affect the facial nerve, hearing and balance.
321.The answer is d.(Moore and Dalley, p 1022.)You send him for a
sinus series because you suspect he has maxillary sinusitis. The maxillary
sinus is the most frequent site of sinusitis. This is likely due to the fact that
its ostium is high on the medial wall of the sinus when erect, thus requir-
ing ciliary action to drain the sinus when in the anatomical position. Lying
on the right side of the head may help this patient drain his left maxillary
sinus. The maxillary sinus ostium is generally large enough that a cannula
can be threaded into the sinus and vacuum applied to help drain the sinus.
Sphenoid sinus pain (answer a)is generally referred to the top of the skull
near the vertex. Anterior (answer b)and posterior (answer c)ethmoidal
sinus pain generally refers to areas around the eyes (either medial or lateral).
Frontal sinusitis pain (answer e)generally presents over the frontal sinus
and tapping on the forehead there will elicit pain.
322.The answer is e.(Moore and Dalley, pp 1150, 1172–1173.) The correct
answer is the internal carotid artery (medial), internal jugular vein (lateral),
454 Anatomy, Histology, and Cell Biology