commissure

commissure /com·mis·sure/ (kom´i-shoor) a site of union of corresponding parts; specifically, the sites of junction between adjacent cusps of the heart valves.commis´sural

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anterior commissure  the band of fibers connecting the parts of the two cerebral hemispheres.

posterior commissure  a large fiber bundle crossing from one side of the cerebrum to the other, dorsal to where the aqueduct opens into the third ventricle.

Gudden's commissure  see supraoptic c's.

Meynert's commissure  see supraoptic c's.

supraoptic commissures  commissural fibers crossing the midline of the human brain dorsal to the caudal border of the optic chiasm, representing the combined commissures of Gudden and Meynert.

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com·mis·sure (km-shr)

n.

1. A line or place at which two things are joined.

2. A tract of nerve fibers passing from one side to the other of the spinal cord or brain.

3. The point, angle, or surface where two parts, such as the eyelids, lips, or cardiac valves, join or connect.

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commis·sural adj.

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commissure (kmish´ur),

n the corners of the oral cavity.

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commissure, commissura

a site of union of corresponding parts, as the angle of the lips or eyelids; used also with specific reference to the sites of junction between adjacent cusps of the heart valves.

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brain commissure

the bands of fibers connecting the parts of the two cerebral hemispheres. They include the corpus callosum, the largest commissure, a rostral commissure which is part of the paleopallium and the fornical commissure which is related to the archipallium, the caudal collicular commissure which connects the caudal colliculi (corpora quadrigemina). Called also cerebral commissure.

cerebral commissure

see brain commissure (above).

fornical commissure

interconnection between the right and left hippocampi. Called also fornical commissure.

habenular commissure

interconnection between the right and left habenular nuclei.

middle commissure

a band of gray matter joining the optic thalami; it develops as a secondary adhesion and may be absent.

posterior commissure

a large fiber bundle crossing from one side of the cerebrum to the other dorsal to where the aqueduct opens into the third ventricle.

spinal cord commissure

the gray and white commissures which connect the two sides of the spinal cord.