Sensory Impairment Related to Level of Spinal Cord Injury
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 Pathways
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…
Retinal Projections to Thalamus, Midbrain, and Brainstem
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…
Vestibular Receptors
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…
Spinal Cord
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,…
Glossopharyngeal (IX) Nerve
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…
Trigeminal Nuclei: Afferent and Central Connections
The principal sensory nucleus, which is located in the lateral pons, receives tactile and proprioceptive sensation. It gives off fibers that travel in the trigeminal lemniscus and the uncrossed dorsal…
Veins of Spinal Cord, Nerve Roots, and Vertebrae
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…
Autonomic Innervation of the Eye
Some of the filaments passing through the superior orbital fissure form the sympathetic root of the ciliary ganglion; their contained fibers pass through it without relaying to become incorporated in…
Trigeminal (V) Nerve
The trigeminal nerve emerges from the anterolateral aspect of the upper pons. The large sensory root conveys sensation from most of the face and scalp; parts of the auricle; and…
