The subarachnoid cisterns are spaces formed by openings in the

subarachnoid space In anatomy, the meninges (, ''singular:'' meninx ( or ), ) are the three membranes that envelop the brain and spinal cord. In mammals, the meninges are the dura mater, the arachnoid mater, and the pia mater. Cerebrospinal fluid is located in th ...

, an

anatomic space {{set index article In anatomy, a spatium or anatomic space is a space (cavity or gap). Anatomic spaces are often landmarks to find other important structures. When they fill with gases (such as air) or liquids (such as blood) in pathological ways, ...

in the

meninges In anatomy, the meninges (, ''singular:'' meninx ( or ), ) are the three membranes that envelop the brain and spinal cord. In mammals, the meninges are the dura mater, the arachnoid mater, and the pia mater. Cerebrospinal fluid is located in th ...

of the

brain A brain is an organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It is located in the head, usually close to the sensory organs for senses such as vision. It is the most complex organ in a v ...

. The space is situated between the two meninges, the

arachnoid mater The arachnoid mater (or simply arachnoid) is one of the three meninges, the protective membranes that cover the brain and spinal cord. It is so named because of its resemblance to a spider web. The arachnoid mater is a derivative of the neural c ...

and the

pia mater Pia mater ( or ),Entry "pia mater"
in
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 ...

Structure

Although the pia mater adheres to the surface of the brain, closely following the contours of its

gyri In neuroanatomy, a gyrus (pl. gyri) is a ridge on the cerebral cortex. It is generally surrounded by one or more sulci (depressions or furrows; sg. ''sulcus''). Gyri and sulci create the folded appearance of the brain in humans and other ma ...

and

sulci Sulci or Sulki (in Greek , Steph. B., Ptol.; , Strabo; , Paus.), was one of the most considerable cities of ancient Sardinia, situated in the southwest corner of the island, on a small island, now called Isola di Sant'Antioco, which is, howev ...

, the arachnoid mater only covers its superficial surface, bridging across the gyri. This leaves wider spaces between the pia and arachnoid and the cavities are known as the subarachnoid cisterns. Although they are often described as distinct compartments, the subarachnoid cisterns are not truly anatomically distinct. Rather, these subarachnoid cisterns are separated from each other by a

trabecula A trabecula (plural trabeculae, from Latin for "small beam") is a small, often microscopic, tissue element in the form of a small beam, strut or rod that supports or anchors a framework of parts within a body or organ. A trabecula generally has ...

ted porous wall with various-sized openings.

Cisterns

There are many cisterns in the brain with several large ones noted with their own name. At the base of the spinal cord is another subarachnoid cistern: the lumbar cistern which is the site for a

lumbar puncture Lumbar puncture (LP), also known as a spinal tap, is a medical procedure in which a needle is inserted into the spinal canal, most commonly to collect cerebrospinal fluid (CSF) for diagnostic testing. The main reason for a lumbar puncture is to ...

. Some major subarachnoid cisterns: *

Cisterna magna The cisterna magna (or cerebellomedullar cistern) is one of three principal openings in the subarachnoid space between the arachnoid and pia mater layers of the meninges surrounding the brain. The openings are collectively referred to as the su ...

also called ''cerebellomedullary cistern'' - the largest of the subarachnoid cisterns. It lies between the

cerebellum The cerebellum (Latin for "little brain") is a major feature of the hindbrain of all vertebrates. Although usually smaller than the cerebrum, in some animals such as the mormyrid fishes it may be as large as or even larger. In humans, the cerebel ...

and the

medulla oblongata The medulla oblongata or simply medulla is a long stem-like structure which makes up the lower part of the brainstem. It is anterior and partially inferior to the cerebellum. It is a cone-shaped neuronal mass responsible for autonomic (involun ...

. It receives CSF from the

fourth ventricle The fourth ventricle is one of the four connected fluid-filled cavities within the human brain. These cavities, known collectively as the ventricular system, consist of the left and right lateral ventricles, the third ventricle, and the fourth ve ...

via the

median aperture In statistics and probability theory, the median is the value separating the higher half from the lower half of a data sample, a population, or a probability distribution. For a data set, it may be thought of as "the middle" value. The basic fe ...

(foramen of Magendie). The cisterna magna contains: # The

vertebral artery The vertebral arteries are major arteries An artery (plural arteries) () is a blood vessel in humans and most animals that takes blood away from the heart to one or more parts of the body (tissues, lungs, brain etc.). Most arteries carry o ...

and the origin of the

posterior inferior cerebellar artery The posterior inferior cerebellar artery (PICA) is the largest branch of the vertebral artery. It is one of the three main arteries that supply blood to the cerebellum, a part of the brain. Blockage of the posterior inferior cerebellar artery can r ...

(PICA) # The ninth (IX), tenth (X), eleventh (XI) and twelfth (XII)

cranial nerves Cranial nerves are the nerves that emerge directly from the brain (including the brainstem), of which there are conventionally considered twelve pairs. Cranial nerves relay information between the brain and parts of the body, primarily to and f ...

Pontine cistern The pontine cistern, also cisterna pontis and cisterna pontocerebellaris is a notable subarachnoid cistern on the ventral aspect of the pons. It contains the basilar artery, and is continuous behind with the subarachnoid space of the spinal cord, ...

. Surrounds the ventral aspect of the

pons The pons (from Latin , "bridge") is part of the brainstem that in humans and other bipeds lies inferior to the midbrain, superior to the medulla oblongata and anterior to the cerebellum. The pons is also called the pons Varolii ("bridge of Va ...

. It receives CSF via the paired

lateral aperture The lateral aperture is a paired structure in human anatomy. It is an opening in each lateral extremity of the lateral recess of the fourth ventricle of the human brain, which also has a single median aperture. The two lateral apertures provide a ...

s. It contains: # The

basilar artery The basilar artery () is one of the arteries that supplies the brain with oxygen-rich blood. The two vertebral arteries and the basilar artery are known as the vertebral basilar system, which supplies blood to the posterior part of the circle of W ...

and the origin of the anteroinferior cerebellar artery (AICA) # The origin of the superior cerebellar arteries # The sixth (VI) cranial nerve *

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 The circle of Willis (also called Wil ...

. It is situated at the base of the brain, between the two

cerebral peduncles The cerebral peduncles are the two stalks that attach the cerebrum to the brainstem. They are structures at the front of the midbrain which arise from the ventral pons and contain the large ascending (sensory) and descending (motor) nerve tract ...

midbrain The midbrain or mesencephalon is the forward-most portion of the brainstem and is associated with vision, hearing, motor control, sleep and wakefulness, arousal (alertness), and temperature regulation. The name comes from the Greek ''mesos'', " ...

and

dorsum sellae The dorsum sellae is part of the sphenoid bone in the skull. Together with the basilar part of the occipital bone it forms the clivus. In the sphenoid bone, the anterior boundary of the sella turcica is completed by two small eminences, one on e ...

and continuous below with the pontine cistern and superiorly with the

chiasmatic cistern The chiasmatic cistern (cistern of chiasma, or suprasellar cistern) is formed as the interpeduncular cistern extends forward across the optic chiasm and onto the upper surface of the corpus callosum – the arachnoid stretches across from one cere ...

. It contains: # 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 ...

# The bifurcation of the basilar artery # Peduncular segments of the posterior cerebral arteries (PCA) # Peduncular segments of the superior cerebellar arteries # Perforating branches of the PCA # The posterior communicating arteries (PCoA) # The

basal vein The basal vein is a vein in the brain. It is formed at the anterior perforated substance by the union of * (a) a ''small anterior cerebral vein'' which accompanies the anterior cerebral artery and supplies the medial surface of the frontal lobe by ...

# The third (III) cranial nerve, which passes between the posterior cerebral and superior cerebellar arteries *

Cerebellopontine angle cistern The cerebellopontine angle (CPA) ( la, angulus cerebellopontinus) is located between the cerebellum and the pons. The cerebellopontine angle is the site of the cerebellopontine angle cistern one of the subarachnoid cisterns that contains cerebr ...

. It is situated at the cerebellopontine angle – the lateral angle between the cerebellum and the pons. It contains: # The seventh (VII) and eighth (VIII) cranial nerves # The anteroinferior cerebellar artery (AICA) # The fifth (V) cranial nerve and the petrosal vein * Superior cistern - It is situated dorsal to the midbrain. Thin, sheet-like extensions of the superior cistern that extend laterally about the midbrain, connecting it to the interpeduncular cistern. Ambient cistern may also refer to the combination of these extensions and the superior cistern. It is composed of a supratentorial and an infratentorial compartment. It contains: # The

great cerebral vein The great cerebral vein is one of the large blood vessels in the skull draining the cerebrum of the brain. It is also known as the "vein of Galen", named for its discoverer, the Greek physician Galen. However, it is not the only vein with this epon ...

# The posterior pericallosal arteries # The third portion of the superior cerebellar arteries # Perforating branches of the posterior cerebral and superior cerebellar arteries # The third portion of the posterior cerebral arteries : Its supratentorial portion contains: # The

# The posterior cerebral artery : Its infratentorial portion contains: # The superior cerebellar artery # The fourth (IV) nerve * Crural cistern. It is situated around the ventrolateral aspect of the midbrain. It contains: # The anterior choroidal artery # The medial posterior choroidal artery # The basal vein * Carotid cistern. It is situated between the carotid artery and the ipsilateral optic nerve. It contains: # The internal carotid artery # The origin of the anterior choroidal artery # The origin of the posterior communicating artery * Insular/Sylvian cistern. It is situated in the fissure between the frontal and temporal lobes. It contains: # The middle cerebral artery # The middle cerebral veins # The fronto-orbital veins # Collaterals to the basal vein * Cistern of lamina terminalis. It is situated just rostral to the third ventricle. It contains: # The anterior cerebral arteries (A1 and proximal A2) # The anterior communicating artery # Heubner's artery # The hypothalamic arteries # The origin of the fronto-orbital arteries * Lumbar cistern. It extends from the conus medullaris (L1-L2) to about the level of the second sacral vertebra. It contains the filum terminale and the nerve roots of the cauda equina. It is from the lumbar cistern that CSF is withdrawn during a

. It is of clinical significance that cerebral arteries, veins and cranial nerves must pass through the subarachnoid space, and these structures maintain their meningeal investment until around their point of exit from the skull.

References

* Nolte, J (2002) The Human Brain, 5th edition. , 87 {{Meninges Meninges

Structure

Cisterns

See also

References