What is the Cisterna Magna? (with picture)

Andy Josiah
Andy Josiah
The pontine cistern contains the Basilar artery, which provides oxygenated blood to the brain.
The pontine cistern contains the Basilar artery, which provides oxygenated blood to the brain.

The cisterna magna, an opening in the subarachnoid cavity in the brain, is so named because of its large size. In fact, it is the largest of the openings that can be found in this gap of the central nervous system. The cisterna magna is also known as the cerebellomedullary cistern.

The alternate name of the cisterna magna, cerebellomedullary cistern, is derived from the opening's location. It runs along the cerebellum, the part of the brain that is responsible for one's movement coordination, as well as for contributing to other functions such as alertness, speech and reaction to emotions such as fear and joy. It is also located close to the upper surface of the medulla oblongata. This is the lower section of the posterior part of the brain called the brain stem, enabling functions such as breathing, blood pressure, heart and respiratory rate, and sexual arousal.

The subarachnoid cavity, where the cisterna magna is located, is also known as the subarachnoid space. It creates a space between the arachnoid mater and the pia mater. These are membranes that represent two of the three meninges covering the central nervous system, specifically the brain and spinal cord. The arachnoid is named for its shape, which resembles that of a spider web.

The third membrane that covers the central nervous system, the dura mater, sits atop both the arachnoid and the pia mater as the system's outermost layer. Surrounding the brain and spinal cord, it keeps a clear, colorless fluid called the cerebrospinal fluid, or liquor cerebrospinalis. It is produced in the choroid plexus and pours into the cistern magna from the lateral and median apertures of one of the brain's fluid-filled cavities, referred to as the fourth ventricle. By infiltrating the cistern among several other regions, the cerebrospinal fluid acts as a floating and protective device for the entire brain.

Accompanying the cisterna magna are several other openings, all of which are smaller in size. The pontine cistern and the interpeduncular cistern can also be found in the subarachnoid space. The former contains a blood vessel called the Basilar artery, which provides oxygenated blood to the brain, while the latter is named after its enclosure of stalk-like structures in the cerebrum, called the cerebral peduncles. Other notable cisterns besides the cisterna magna include the superior cistern, which contains a large blood vessel known as the great cerebral vein; and the ambient cistern, which can be considered an extension of the aforementioned opening.

You might also Like

Readers Also Love

Discussion Comments


@seag47 – My neighbor's small child also has the Dandy Walker malformation, and unfortunately, not much is known about the cause or a way to cure the syndrome. She has been donating money for research into this condition, and she recently held a fundraiser in our neighborhood, encouraging other people to do the same.

Her toddler will have to live with a severe disability brought on by this defect. He can barely control his movements at all, and he will have to have special schooling and therapy for years to come.

Research is expensive, and unless the company looking into the condition receives continuous funding, a cure will not be found. I think the government provides a certain amount of funding, but families and friends of those affected by it provide a lot of the support needed.


My friend recently found out that her child has Dandy Walker syndrome. It is a kind of birth defect, but sometimes the signs don't show up until later in life. Her son is ten, and he has just been diagnosed with it.

She had been noticing for awhile that his head seemed quite large. She also noticed that he seemed to be having trouble with his coordination. His eyes started jerking around, and he seemed really irritable.

Last month, he started convulsing, so she took him to the hospital. There, they discovered the defect in his cerebellum and the cisterna magna, along with the other spaces filled with fluid in his brain.

Does anyone know if there is a cure in the works for this condition? My friend is looking for answers, and so far, no one has been able to help her out much.


My cousin developed an arachnoid cyst. It was caused by her bout with meningitis, which infected the cerebrospinal fluid in her cisterna magna.

She noticed she had meningitis after she got a fever and a stiff neck. She took antibiotics to treat it, but later on, she developed the cyst.

She knew something was wrong when she started vomiting and feeling very dizzy. She got an intense headache, and she had trouble maintaining her balance.

Her doctor found the cyst and decided she needed surgery to drain the cyst fluid. Once he punctured the cyst, the cerebrospinal fluid absorbed it as it flowed out.


By holding the cerebrospinal fluid, the cisterna magna does a great service to the body. I have read that the fluid delivers nutrition to the brain, and it also gets rid of waste. It feeds the brain and spine and keeps them free of toxins.

Also, if you get jostled around violently, the fluid in the cisterna magna can keep your brain from suffering serious damage. My brother was in a car wreck, and though he did suffer whiplash, he was spared from brain damaged because of this fluid-filled cavity.

I think of it like the padding in a football uniform, only instead of solid material, it is liquid. Even in the face of extreme physical impact, it keeps the player safe.

Post your comments
Forgot password?
    • The pontine cistern contains the Basilar artery, which provides oxygenated blood to the brain.
      The pontine cistern contains the Basilar artery, which provides oxygenated blood to the brain.