The chiasmatic cistern (cistern of chiasma, or suprasellar cistern) is formed as the

interpeduncular cistern The interpeduncular cistern of Sweeney is the subarachnoid cistern that encloses the cerebral peduncles and the structures contained in the interpeduncular fossa and contains the arterial circle of Willis as well as the oculomotor nerve Th ...

extends forward across the

optic chiasm In neuroanatomy, the optic chiasm, or optic chiasma (; , ), is the part of the brain where the optic nerves cross. It is located at the bottom of the brain immediately inferior to the hypothalamus. The optic chiasm is found in all vertebrate ...

and onto the upper surface of the

corpus callosum The corpus callosum (Latin for "tough body"), also callosal commissure, is a wide, thick nerve tract, consisting of a flat bundle of commissural fibers, beneath the cerebral cortex in the brain. The corpus callosum is only found in placental ...

– the

arachnoid Arachnoid may refer to: * Relating to arachnids * Arachnoid (astrogeology), a geological structure found only on the planet Venus * Arachnoid (botany), referring to organs with a cobwebby exterior appearance * Arachnoid granulation, small protr ...

stretches across from one cerebral hemisphere to the other immediately beneath the free border of the

falx cerebri The falx cerebri (also known as the cerebral falx) is a large, crescent-shaped fold of dura mater that descends vertically into the longitudinal fissure between the cerebral hemispheres of the human brain,Saladin K. "Anatomy & Physiology: The Un ...

, and thus leaves a space in which the anterior cerebral arteries are contained. The "leaf" or extension of the chiasmatic cistern above the chiasma, which is separated from the

optic recess At the junction of the floor and anterior wall of the third ventricle, immediately above the optic chiasma, the ventricle presents a small angular recess or diverticulum, the optic recess (or supraoptic recess). Additional images File:Gray736. ...

of the

third ventricle The third ventricle is one of the four connected ventricles of the ventricular system within the mammalian brain. It is a slit-like cavity formed in the diencephalon between the two thalami, in the midline between the right and left lateral ...

by the thin

lamina terminalis The median portion of the wall of the forebrain consists of a thin lamina, the lamina terminalis, which stretches from the interventricular foramen (Foramen of Monro) to the recess at the base of the optic stalk (optic nerve) and contains the va ...

, has been called the suprachiasmatic cistern. As spaces filled with freely circulating

cerebrospinal fluid Cerebrospinal fluid (CSF) is a clear, colorless body fluid found within the tissue that surrounds the brain and spinal cord of all vertebrates. CSF is produced by specialised ependymal cells in the choroid plexus of the ventricles of the bra ...

, cisterns receive little direct study, but are mentioned in pathological conditions. Cysts and tumors of the lamina terminalis extend into the suprachiasmatic cistern, as can pituitary tumors, or the cistern can be partially or completely effaced by injury and

hematoma A hematoma, also spelled haematoma, or blood suffusion is a localized bleeding outside of blood vessels, due to either disease or trauma including injury or surgery and may involve blood continuing to seep from broken capillaries. A hematoma is ...

or by blockage of the

cerebral aqueduct The cerebral aqueduct (aqueductus mesencephali, mesencephalic duct, sylvian aqueduct or aqueduct of Sylvius) is a conduit for cerebrospinal fluid (CSF) that connects the third ventricle to the fourth ventricle of the ventricular system of the brai ...

References

External links

NIF Search - Chiasmatic Cistern
via the

Neuroscience Information Framework The Neuroscience Information Framework is a repository of global neuroscience web resources, including experimental, clinical, and translational neuroscience databases, knowledge bases, atlases, and genetic/ genomic resources and provides many aut ...

Meninges {{neuroanatomy-stub