AN62.1-6 | Cranial nerve nuclei & Cerebral hemispheres — Glossary

A cluster of nerve cell bodies within the brainstem (or spinal cord for CN XI) that serves as the origin or termination point of a cranial nerve's fibres.

One of seven longitudinal cell columns in the brainstem, each carrying a specific type of nerve fibre (e.g. GSE, SVE), derived from embryological development.

A region of the cerebral cortex defined by its cytoarchitecture (cellular structure), numbered by Korbinian Brodmann; used to map functional areas such as area 4 (motor) and area 17 (visual).

The deep groove separating the frontal lobe (motor cortex) from the parietal lobe (sensory cortex), also called the fissure of Rolando.

The deep cleft (Sylvian fissure) separating the temporal lobe below from the frontal and parietal lobes above; contains the insula deep within.

The largest commissural fibre bundle connecting the left and right cerebral hemispheres, with four parts: rostrum, genu, body, and splenium.

A V-shaped band of white matter between the caudate nucleus, thalamus, and lentiform nucleus, carrying ascending sensory and descending motor fibres; a common site of lacunar infarcts.

Deep grey matter nuclei (caudate, putamen, globus pallidus) involved in regulating voluntary movement; damage causes Parkinson's disease, chorea, or hemiballismus.

The caudate nucleus and putamen considered together; the main input structure of the basal ganglia receiving cortical projections.

The main output nucleus of the basal ganglia, divided into external (GPe) and internal (GPi) segments; GPi projects to the thalamus to regulate motor activity.

A paired ovoid grey matter mass forming the lateral wall of the third ventricle; relays and processes sensory, motor, and limbic information to the cerebral cortex.

The ventral part of the diencephalon controlling autonomic functions, endocrine regulation (via pituitary), temperature, hunger, thirst, circadian rhythms, and emotional behaviour.

An arterial anastomotic ring at the base of the brain formed by branches of the internal carotid and vertebrobasilar systems, providing collateral blood flow between anterior and posterior circulations.

A saccular outpouching at arterial bifurcations of the circle of Willis (most commonly the anterior communicating artery); rupture causes subarachnoid haemorrhage.

Non-fluent (expressive) aphasia caused by damage to Broca's area (areas 44/45) in the left inferior frontal gyrus; the patient understands speech but cannot produce fluent speech.

Fluent (receptive) aphasia caused by damage to Wernicke's area (area 22) in the left superior temporal gyrus; speech is fluent but meaningless, with impaired comprehension.

Violent involuntary flinging movements of one side of the body caused by a lesion (usually infarct) of the contralateral subthalamic nucleus.

A neural circuit for emotion and memory: hippocampus → fornix → mammillary body → mammillothalamic tract → anterior thalamic nucleus → cingulate gyrus → parahippocampal gyrus → hippocampus.

The major descending motor pathway from the primary motor cortex through the posterior limb of the internal capsule to the spinal cord, controlling voluntary movement of the contralateral body.

A motor nucleus in the medulla providing SVE fibres to cranial nerves IX, X, and the cranial root of XI; innervates muscles of the pharynx and larynx for swallowing and phonation.