Subarachnoid cisterns

Subarachnoid Cisterns

The subarachnoid cisterns are spaces within the subarachnoid space of the central nervous system that are filled with cerebrospinal fluid (CSF). These cisterns are formed by the separation of the arachnoid mater from the pia mater, creating expanded areas that serve as reservoirs for CSF. They play a crucial role in cushioning the brain, maintaining intracranial pressure, and facilitating the circulation of CSF.

Diagram of the subarachnoid cisterns.

Anatomy

The subarachnoid cisterns are located at various points around the brain and brainstem. Some of the major cisterns include:

Cisterna Magna

The cisterna magna, also known as the cerebellomedullary cistern, is one of the largest subarachnoid cisterns. It is located between the cerebellum and the medulla oblongata. This cistern is a common site for cerebrospinal fluid sampling in procedures such as a cisternal puncture.

Pontine Cistern

The pontine cistern is situated anterior to the pons and contains the basilar artery. It is an important cistern for the circulation of CSF around the brainstem.

Interpeduncular Cistern

The interpeduncular cistern is located between the cerebral peduncles of the midbrain. It contains the circle of Willis, a critical arterial structure that supplies blood to the brain.

Chiasmatic Cistern

The chiasmatic cistern is found near the optic chiasm, where the optic nerves cross. It is involved in the circulation of CSF around the hypothalamus and pituitary gland.

Quadrigeminal Cistern

The quadrigeminal cistern, also known as the superior cistern, is located posterior to the midbrain and above the cerebellum. It contains the great cerebral vein and the pineal gland.

Function

The primary function of the subarachnoid cisterns is to act as reservoirs for cerebrospinal fluid, which cushions the brain and spinal cord, provides nutrients, and removes waste products. The cisterns also facilitate the circulation of CSF throughout the central nervous system, helping to maintain intracranial pressure and protect the brain from mechanical injury.

Clinical Significance

Subarachnoid cisterns are clinically significant in various medical conditions. For instance, subarachnoid hemorrhage can occur when blood enters the subarachnoid space, often affecting the cisterns. Imaging techniques such as MRI and CT scans are used to visualize these cisterns in the diagnosis and management of neurological disorders.

Related pages

• Cerebrospinal fluid
• Arachnoid mater
• Pia mater
• Subarachnoid space
• Central nervous system