What is the arachnoid space?

The subarachnoid space consists of the cerebrospinal fluid (CSF), major blood vessels, and cisterns. The cisterns are enlarged pockets of CSF created due to the separation of the arachnoid mater from the pia mater based on the anatomy of the brain and spinal cord surface.

What does the arachnoid do?

The arachnoid mater makes arachnoid villi, small protrusions through the dura mater into the venous sinuses of the brain, which allow CSF to exit the subarachnoid space and enter the blood stream.

What does the subarachnoid space do?

The primary function of the subarachnoid space is to house CSF which cushions the brain and the spinal cord whilst also providing nutrients and removing waste.

Why is it called the arachnoid space?

The arachnoid mater, named for its spiderweb-like appearance, is a thin, transparent membrane surrounding the spinal cord like a loosely fitting sac. Continuous with the cerebral arachnoid above, it passes through the foramen magnum and descends caudally to the S2 vertebral level.

What is the arachnoid and what is its function in the brain?

The passageways of the arachnoid mater are critically important for the passage of cerebrospinal fluid (CSF). This fluid is created in the brain (specifically, in the choroid plexus of the lateral ventricles) and passes through a network of ventricles until it is transported into the arachnoid space.

Where is the arachnoid located?

The arachnoid (Gk. spider) is a delicate fibrocellular layer beneath the dura (separated by potential subdural space) that is connected to the pia mater covering the brain by numerous fibrocellular bands that cross the cerebrospinal fluid-filled subarachnoid space.

Where are meninges located?

Three layers of membranes known as meninges protect the brain and spinal cord. The delicate inner layer is the pia mater. The middle layer is the arachnoid, a web-like structure filled with fluid that cushions the brain. The tough outer layer is called the dura mater.

What do subarachnoid mean?

In practice, subarachnoid usually refers to the space between the arachnoid and the pia mater, the innermost membrane surrounding the central nervous system. The subarachnoid space is a potential space. It normally contains cerebrospinal fluid. A subarachnoid hemorrhage is a bleed into this space.

What does prominent subarachnoid space mean?

Benign enlargement of subarachnoid space (BESS) in infancy is the most common cause of macrocephaly and characterized clinically with large head circumference, normal or mildly motor and language delay and increased cerebrospinal fluid (CSF) in the subarachnoid space with normal ventricles or mild ventriculomegaly.

What is the purpose of CSF?

Also called CSF. Cerebrospinal fluid (CSF, shown in blue) is made by tissue that lines the ventricles (hollow spaces) in the brain. It flows in and around the brain and spinal cord to help cushion them from injury and provide nutrients.

What happens if the arachnoid mater is damaged?

The arachnoid mater is the middle tissue of the meninges. Damage to the arachnoid mater can cause swelling and inflammation. This swelling can cause nerves in the spine to stick together, altering nerve function and triggering intense pain. Arachnoiditis is almost always caused by an injury.

Where does the arachnoid mater end?

S2 vertebral level 2

Gross Anatomy
The spinal arachnoid mater becomes continuous with the cerebral arachnoid mater as it traverses the foramen magnum and terminates at the S2 vertebral level 2.

What area of the brain controls blood pressure?

The brain stem sits beneath your cerebrum in front of your cerebellum. It connects the brain to the spinal cord and controls automatic functions such as breathing, digestion, heart rate and blood pressure.

What part of the brain controls sleep?


The hypothalamus, a peanut-sized structure deep inside the brain, contains groups of nerve cells that act as control centers affecting sleep and arousal.

Which part of the brain controls long term memory?

The hippocampus

The hippocampus is the catalyst for long-term memory, but the actual memory traces are encoded at various places in the cortex.

Which part of the brain controls heart rate and breathing?


Medulla. At the bottom of the brainstem, the medulla is where the brain meets the spinal cord. The medulla is essential to survival. Functions of the medulla regulate many bodily activities, including heart rhythm, breathing, blood flow, and oxygen and carbon dioxide levels.

Do emotions come from the heart or brain?

Pain is not only a sensory experience, but also can be associated with emotional, cognitive, and social components. The heart is considered the source of emotions, desire, and wisdom.

Does the brain feel pain?

The brain itself does not feel pain because there are no nociceptors located in brain tissue itself. This feature explains why neurosurgeons can operate on brain tissue without causing a patient discomfort, and, in some cases, can even perform surgery while the patient is awake.

Can the heart function without the brain?

The heart can beat on its own

The heart does not need a brain, or a body for that matter, to keep beating. The heart has its own electrical system that causes it to beat and pump blood. Because of this, the heart can continue to beat for a short time after brain death, or after being removed from the body.

Which is more powerful mind or heart?

The heart is the most powerful generator of electromagnetic energy in the human body, producing the largest rhythmic electromagnetic field of any of the body’s organs. The heart’s electrical field is about 60 times greater in amplitude than the electrical activity generated by the brain.

What is the most important brain or heart?

Many people would probably think it’s the heart, however, it’s the brain! While your heart is a vital organ, the brain (and the nervous system that attaches to the brain) make up the most critical organ system in the human body.

What is the most important organ in the body?

The brain

The brain is arguably the most important organ in the human body. It controls and coordinates actions and reactions, allows us to think and feel, and enables us to have memories and feelings—all the things that make us human.

What is the most useless organ?

The appendix

The appendix may be the most commonly known useless organ.
While plant-eating vertebrates still rely on their appendix to help process plants, the organ is not part of the human digestive system.

What organ can you not live without?

While you can’t live without your liver, you can live with just part of it. Your liver is the only organ in your body that can regrow after parts of it have been removed or damaged. In fact, it can grow back to its full size in just months.

What is the least important organ?

Here are some of the “non-vital organs”.

  • Spleen. This organ sits on the left side of the abdomen, towards the back under the ribs. …
  • Stomach. …
  • Reproductive organs. …
  • Colon. …
  • Gallbladder. …
  • Appendix. …
  • Kidneys.

What is the weirdest body part?

Ten weird body parts you didn’t know you still had – from claw retractors to a third eyelid

  • 1) A tail. Before you were born, you had a tail, albeit only for a few weeks. …
  • 2) Third eyelid. …
  • 3) Wisdom teeth. …
  • 4) Darwin’s Point. …
  • 5) Ear wigglers. …
  • 6) Another nose. …
  • 7) Claw retractor. …
  • 8) Baby animal grip.

What is the coolest organ?

Your liver does three main jobs: It filters harmful things from your blood, stores fuel, and makes a liquid called bile that helps you digest food. But that’s just the beginning. This amazing organ plays a part in hundreds of other bodily functions.