The frontal sinus is innervated by the supraorbital and supratrochlear branches of the frontal nerve. All nerves mentioned in this question are branches of ophthalmic division (V1) of the trigeminal (fifth cranial) nerve. The anterior (choice A) and the posterior (choice D) ethmoidal nerves arise from the nasociliary nerve (choice C). They innervate the ethmoid and sphenopalatine sinuses. The lacrimal nerve (choice B) carries in its terminal segment the parasympathetic innervation to the lacrimal gland and provides sensory innervation to the upper eyelid.

53) A neurologist is performing the neurological examination on a patient who recently suffered a head trauma. You note that, as part of the examination, she uses a cotton swab to touch the upper part of the auricle, the external auditory meatus, and the lobule. The external auditory meatus of the ear is innervated by which of the following?

The vagus (tenth cranial) nerve innervates the external auditory meatus of the ear. The great auricular nerve (choice B) innervates the lobule of the auricle and the auriculotemporal nerve (choice C), the superior aspect of the auricle. In fact, a sensory test which includes these three parts of the ear tests the integrity of the trigeminal (fifth cranial) nerve by the auriculotemporal nerve, the vagus (tenth cranial) nerve by its branch innervating the auditory meatus, and spinal nerves C2-3 by their great auricular branch. The test thus covers the upper and lower medulla and the upper spinal cord. The greater occipital nerve (choice D) is a branch of the cervical plexus originating from C2 and innervates the scalp of the back of the head. The facial (seventh cranial) nerve provides only motor innervation to the face and scalp areas.

Arrow 3 points to the tunica intima. The carotid artery is an elastic artery, which contains the following layers aside from the tunica intima: Tunica externa (arrow 1), and tunica media (arrow 5). In a carotid dissection, the tunica intima can elevate or separate from the tunica media with accompanying hemorrhage of the arterial wall. The most common clinical signs are ophthalmological manifestations including painful Horner syndrome, palsy of the oculomotor nerve, diplopia, and transient monocular visual loss. Arrow 2 points to a vasa vasorum, vessels which nourish the thick wall of the aorta. Arrow 4 points to the adipose tissue in the tunica externa.

55) In the brain, the amygdala plays an important role in emotional processing. Patients with lesion of the amygdala display impairment in enhanced perception of emotionally salient events. Which of the following is a major output pathway from the amygdala?

The stria terminalis or fasciculus of Foville is one of the major output pathways from the amygdala to the septal, hypothalamic, and thalamic nuclei. Another main amygdaloid output pathway is the ventral amygdalofugal pathway. The fasciculus arcuatus (choice A) or superior longitudinal fasciculus is a bundle of fibers in the cerebrum connecting ipsilateral regions of the frontal, temporal, parietal, and occipital lobes. The fasciculus cuneatus (choice B) carries ascending sensory fibers in the dorsal funiculus of the spinal cord and terminates in the nucleus cuneatus of the medulla oblongata. The fasciculus of Vicq d’Azyr (choice C) or mammillothalamic tract connects the mammillary bodies to the anterior nuclei of the thalamus. This bundle of fibers forms part of Papez circuit, which is also involved in emotional processing. Another part of Papez circuit is the fornix (choice D), a large efferent pathway from the hippocampus.

56) An infant is born anencephalic. He presents without both a forebrain and a cerebrum. The remaining brain tissue is exposed, not covered by bone or skin. The infant is blind, deaf, unconscious, and unable to feel pain. Because the infant has a rudimentary brainstem, reflex actions such as respiration (breathing) and responses to sound or touch occur. However, the lack of a functioning cerebrum permanently rules out the possibility of ever gaining consciousness. Anencephaly is the result of a defect in which of the following?

Malclosure of the rostral neuropore during the fourth week of development results in anencephaly and is lethal in the affected newborn. The condition is better termed meroanencephaly because of the presence of the rudimentary brainstem with some functioning nervous tissues. Defects in the closure of the caudal neuropore (choice A) result in varying conditions of spina bifida at the lower end of the spinal cord. The first branchial arch (choice C) and the somites (choice D) do not play any role in the formation of the brain. Fusion of the metopon or forehead (choice E) occurs after birth and also does not play a role in brain formation.

57) As the consulting physician to the US Open, you are asked to examine a golfer who complains of increased pain with right wrist flexion and pronation activities. The patient also reports discomfort even when simply shaking hands with someone. Examination reveals also decreased sensation in the territory of the ulnar nerve. Your diagnosis is golfer’s elbow, affecting mostly the superficial flexor muscles of the forearm. This group of muscles has a common origin from which of the following bony landmarks?

The superficial layer of flexor muscles of the forearm all originate from the medial epicondyle of the humerus. Thus, this condition is also called medial epicondylitis and the most common finding is tenderness with palpation over the anterior aspect of the medial epicondyle. The muscles involved are most often the Pronator Teres, Flexor Carpi Radialis, and Palmaris Longus. The Flexor Digitorum Superficialis and Flexor Carpi Ulnaris may also be affected. There is no muscle attachment to the head of the radius (choice A). The lateral epicondyle of the humerus (choice B) is the attachment point of the common extensor tendon. The olecranon process of the ulna (choice D) is the attachment point for the Triceps Brachii, Flexor Carpi Ulnaris, and Anconeus. The tuberosity of the radius (choice E) receives the distal tendon of the biceps brachii.

58) A professional football player was diving for a touchdown when his face mask was grabbed and wrenched, causing neck hyperextension and rotation to the right. When brought to the sideline, the player complained of a burning sensation radiating down the right upper extremity and neurological examination revealed right lateral weakness of this limb. Movements affected were arm rotation and flexion, elbow flexion, forearm supination, and thumb flexion. The patient is diagnosed with a brachial plexus injury at the level of C6.
Which of the following muscles can perform arm and elbow flexion along with forearm supination?

The biceps brachii muscle attaches proximally by its short head to the coracoid process of the scapula and by its long head to the supraglenoid tubercle. Distally it attaches by a strong tendon to the tuberosity of the radius and by an aponeurosis to the ulna. It thus can perform arm and elbow flexion along with forearm supination. The brachialis (choice B) attaches proximally to the anterior aspect of the lower half of the humerus and distally to the coronoid process of the ulna. It can only perform elbow flexion. The brachioradialis (choice C) attaches from the lateral supracondylar ridge of the humerus to the base of the styloid process of the radius. Although innervated by the nerve to the extensor compartment, the radial nerve, it performs elbow flexion and forearm pronation. The coracobrachialis (choice D) attaches from the coracoid process of the scapula to the anterior aspect of the upper half of the humerus. It performs arm flexion and weak adduction. The supinator (choice E) attaches proximally to the lateral epicondyle of the humerus and the annular ligament of the radius. Distally, it covers nearly the upper third of the radius and attaches to its lateral anterior aspect. It supinates the forearm, but is a weaker supinator than the biceps brachii.

59) In cleaning the teeth in a patient, a dental hygienist accidentally cuts the gums of the posterior two molar teeth in the lower jaw on the lateral side. The pain of this injury is registered by which of the following nerves?