Neuroanatomy Gross Morphology and Tractology Flashcards

Vocabulary flashcards covering fundamental neuroanatomical terminology, gross brain morphology, tracts, nuclei, and functional cortical areas based on the lecture transcript by Dr. Sameh Doss.

Tract

A group of nerve fibres inside the central nervous system (CNS) having the same origin, course, termination, and function.

Bundle or Fasciculus

A group of nerve fibres inside the central nervous system (CNS) having different origins, terminations, and functions.

Peduncle

A thick bundle supporting part of the brain, such as the cerebral peduncles or cerebellar peduncles.

Nucleus (CNS)

A group of nerve cells inside the central nervous system (CNS) lying very close to each other and sharing the same function.

Ganglion

A group of nerve cells outside the central nervous system (CNS), in relation to sensory or autonomic nerves.

Synapse or Relay

The region of contact of the axon of one neurone with the dendrites or cell body of another neurone.

Pathway

A series of neurones transmitting impulses inside or outside the central nervous system (CNS).

Commissure

A band of grey matter or white matter connecting a part of the central nervous system (CNS) on one side with the same part on the opposite side.

Decussation

The criss-crossing of fellow tracts in the middle line.

Lemniscus

A band of ascending sensory fibres in the brain stem that begins from a decussation below and ascends to end in the thalamus above.

Exteroceptive Sensation

Sensations originating from the skin, including pain, touch, and temperature.

Proprioceptive Sensation

Sensations originating from muscles, ligaments, joints, and fascia, including sense of position, passive movements, and vibrations.

Conus Medullaris

The tapering conical extremity forming the lower end of the spinal cord.

Cauda Equina

A bundle formed by the lumbar, sacral, and coccygeal nerves occupying the vertebral canal below the level of the lower border of L1 vertebra in adults.

Filum Terminale

A glistening thread formed by pia mater ending at the apex of the conus medullaris, descending through the sacral hiatus to attach to the back of the coccyx.

Denticulate Ligaments

Serrated lateral extensions of thick pia mater situated between ventral and dorsal nerve roots that attach the spinal cord to the dura mater.

Arteria Radicularis Magna

The largest radicular artery, arising from the 2nd lumbar artery, which supplies the lumbar enlargement of the spinal cord.

Pyramid (Medulla Oblongata)

An elongated elevation on the anterolateral surface of the medulla oblongata formed by the pyramidal (corticospinal) tract.

Olive (Medulla Oblongata)

An oval elevation on the anterolateral surface of the medulla oblongata formed by the underlying inferior olivary nucleus.

Ponto-Cerebellar Angle

A triangular space between the lower border of the middle cerebellar peduncle, the upper border of the medulla, and the cerebellum, where the 7th and 8th cranial nerves emerge.

Facial Colliculus

A rounded swelling on the lower part of the medial eminence in the floor of the fourth ventricle produced by motor fibres of the facial nerve encircling the abducent nucleus.

Interpeduncular Fossa

A rhomboidal-shaped space at the central region of the base of the brain bounded anteriorly by the optic chiasma, anterolaterally by optic tracts, posterolaterally by cerebral peduncles, and posteriorly by the upper border of the pons.

Anterior Perforated Substance

An area at the base of each cerebral hemisphere perforated by central branches of the anterior and middle cerebral arteries, lying behind the olfactory trigone.

Insula

The part of the cerebral cortex hidden at the bottom of the lateral sulcus, possessing a conical mass whose apex is called the limen insulae.

Broca's Speech Area

A motor region (areas 44 and 45) in the posterior part of the inferior frontal gyrus of the dominant hemisphere controlling speech motor functions.

Wernicke's Speech Area

An auditory association region (area 22) in the posterior part of the superior temporal gyrus responsible for understanding spoken language.

Corpus Striatum

The collective term for the caudate nucleus, the lentiform nucleus, and the intervening anterior limb of the internal capsule.

Internal Capsule

A broad, V-shaped lamina of white matter made of projection fibres lying medial to the lentiform nucleus and lateral to the head of the caudate nucleus and thalamus.

Substantia Gelatinosa of Rolando

A sensory nucleus at the apex of the posterior horn of the spinal cord that receives pain and temperature impulses and gives rise to the lateral spinothalamic tract.

Upper Motor Neurones

Motor neurones of the cerebral cortex and subcortical centres whose axons form pyramidal and extrapyramidal tracts descending to end on cranial nerve motor nuclei or spinal cord anterior horn cells.

Lower Motor Neurones

Motor cells located in the motor nuclei of cranial nerves and spinal cord anterior horn cells whose axons run in peripheral nerves to supply skeletal muscles.

Medial Longitudinal Bundle (MLB)

An associative coordinating band in the brain stem extending from the floor of the third ventricle to the lower medulla, linking extraocular muscle nuclei (CN III, IV, VI) with vestibular and auditory inputs.