The subarachnoid cisterns are spaces formed by openings in the subarachnoid space, 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 (; meninx ; ) 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 the subarachnoid spac ...

of the

brain The brain is an organ (biology), organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It consists of nervous tissue and is typically located in the head (cephalization), usually near organs for ...

. 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 cr ...

and the

pia mater Pia mater ( or ),Entry "pia mater"
in
cerebrospinal fluid Cerebrospinal fluid (CSF) is a clear, colorless Extracellular fluid#Transcellular fluid, transcellular body fluid found within the meninges, meningeal tissue that surrounds the vertebrate brain and spinal cord, and in the ventricular system, ven ...

(CSF).

Structure

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

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

and

sulci Sulci or Sulki (in Greek , Stephanus of Byzantium, Steph. B., Ptolemy, Ptol.; , Strabo; , Pausanias (geographer), Paus.), was one of the most considerable cities of ancient Sardinia, situated in the southwest corner of the island, on a small isla ...

, 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 (: trabeculae, from Latin for 'small beam') is a small, often microscopic, biological tissue, tissue element in the form of a small Beam (structure), beam, strut or rod that supports or anchors a framework of parts within a body or ...

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. Some major subarachnoid cisterns: *

Cisterna magna The cisterna magna (posterior cerebellomedullary cistern, or cerebellomedullary cistern) is the largest of the subarachnoid cisterns. It occupies the space created by the angle between the caudal/inferior surface of the cerebellum, and the dorsa ...

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

cerebellum The cerebellum (: cerebella or cerebellums; 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 it or eve ...

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 ...

via the

median aperture The median aperture (median aperture of fourth ventricle or foramen of Magendie) is an opening at the caudal portion of the roof of the fourth ventricle. It allows the flow of cerebrospinal fluid (CSF) from the fourth ventricle into the cisterna ...

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

vertebral artery The vertebral arteries are major artery, arteries of the neck. Typically, the vertebral arteries originate from the subclavian arteries. Each vessel courses superiorly along each side of the neck, merging within the skull to form the single, m ...

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 ...

(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 prepontine cistern, or pontine cistern is one of the subarachnoid cisterns situated ventral to the pons. It contains the basilar artery. Each lateral aperture opens into the pontine cistern just posterior to the cranial nerve VIII. Anatom ...

. Surrounds the ventral aspect of the

pons The pons (from Latin , "bridge") is part of the brainstem that in humans and other mammals, 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 ...

. It receives CSF via the paired

lateral aperture The lateral aperture, lateral aperture of fourth ventricle or foramen of Luschka (after anatomist Hubert von Luschka)Hube ...

s. It contains: # The

basilar artery The basilar artery (U.K.: ; U.S.: ) 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 o ...

and the origin of the

anterior inferior cerebellar artery The anterior inferior cerebellar artery (AICA) is one of three pairs of artery, arteries that supplies blood to the cerebellum. It arises from the basilar artery on each side at the level of the junction between the medulla oblongata and the pons ...

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

Interpeduncular cistern The interpeduncular cistern (or basal cistern) is the subarachnoid cistern situated between the dorsum sellae (anteriorly) and the two cerebral peduncles at the front of the midbrain. Its roof is represented by the floor of the third ventricle ...

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

midbrain The midbrain or mesencephalon is the uppermost portion of the brainstem connecting the diencephalon and cerebrum with the pons. It consists of the cerebral peduncles, tegmentum, and tectum. It is functionally associated with vision, hearing, mo ...

and dorsum sellae and continuous below with the pontine cistern and superiorly with the chiasmatic cistern. 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 vertebrates, ...

# 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 third (III) cranial nerve, which passes between the posterior cerebral and superior cerebellar arteries * Cerebellopontine angle cistern. 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 * Quadrigeminal 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 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 basal vein # 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 * Cistern of lateral cerebral fossa. 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 The cauda equina () is a bundle of spinal nerves and spinal nerve rootlets, consisting of the second through fifth lumbar nerve pairs, the first through fifth sacral nerve pairs, and the coccygeal nerve, all of which arise from the lumbar enl ...

. It is from the lumbar cistern that CSF is withdrawn during a lumbar puncture.

Clinical significance

It is clinically significant that cerebral arteries, veins, and cranial nerves traverse through the subarachnoid space, maintaining their meningeal covering until they exit the skull.

References

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

Structure

Cisterns

Clinical significance

See also

References