CHIASMAL AND POSTCHIASMAL NEUROLOGIC DEFICITS Lesions at the optic chiasm will result in bitemporal hemianopsia, caused by damage to the fibers from the nasal segment of both retinas. Interruption of…
Segments C5 to T1 innervate the arm and hand, with the anterolateral aspect of the shoulder supplied by C5. The thumb and index finger are good markers for C6, the…
OLFACTORY NERVE DISORDERS Anosmia is not always apparent to the patient, and due to the close association of flavor perception and olfaction, may be reported as altered taste rather than…
From the jugular foramen, the nerve arches forward between the internal jugular vein and internal carotid artery, then passes deep to the styloid process, and curves behind the stylopharyngeus muscle…
The vestibular labyrinth receives dual innervation. The distal axonal processes of the bipolar vestibular afferent neurons have cell bodies housed in the vestibular ganglion of the internal acoustic meatus. The…
Meninges. The cord is surrounded by dura, arachnoid, and pia mater, which are continuous with the corresponding layers of the cerebral meninges at the foramen magnum. The spinal dura mater,…
The posterior funiculus, made up of the fasciculus gracilis and the fasciculus cuneatus, carries fibers that signal discriminative touch or pressure, muscle length and tension, and joint position. Some afferent…
As shown in the illustration, rubrospinal fibers decussate almost immediately on leaving the red nucleus to descend through the lateral part of the brainstem to the spinal cord. In the…
MOTOR IMPAIRMENT The degree of motor dysfunction depends on the extent of the spinal cord lesion. Complete lesions destroy all function below the affected level. Incomplete lesions cause partial weakness,…
The external vertebral plexus consists of anterior and posterior parts, which anastomose freely. The veins forming the anterior external plexus lie in front of the vertebral bodies, from which they…
