Corticospinal (Pyramidal) System: Motor Component
The direct motor component of the pyramidal tract runs from the precentral gyrus through the posterior limb of the internal capsule and into the midbrain, where it gives slips to…
Control of Eye Movements
The medial and lateral rectus muscles move the eyeball horizontally, causing the cornea to look medially or laterally. The actions of the superior and inferior rectus muscles and those of…
Incomplete Spinal Cord Syndromes
AUTONOMIC IMPAIRMENT In addition to its somatic components, the spinal cord also contains autonomic nerve fibers, carried in the intermediolateral columns. A lesion at any level may cause sphincter dysfunction….
Pathway of Sound Reception
DISORDERS OF THE VESTIBULOCOCHLEAR NERVE AND SYSTEM Vestibular Ménière disease is an idiopathic process characterized by bouts of episodic vertigo, fluctuating but eventually progressive sensorineural hearing loss, tinnitus, and a…
Anatomy of Taste Buds and Their Receptors
Each taste bud consists of up to 100 polarized neuroepithelial cells that form “islands” of columnar pseudostratified cells embedded in the epithelium. Each bud has a central taste pore through…
Canalith Repositioning (Epley Maneuver)
Related posts: Arteries of Spinal Cord Mandibular Nerve (V3) Cervical Spondylosis Distribution of Motor and Sensory Fibers Cell Types of Nervous System Autonomic Nerves in Neck
Trigeminal Nuclei: Central and Peripheral Connections
The mandibular nerve (V3) is the largest branch of the trigeminal nerve and consists of a large sensory root and a small trigeminal motor root. The sensory portion innervates the…
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…
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…
