CSF then flows through the cerebral aqueduct (aqueduct of Sylvius or mesencephalic aqueduct) into the 4th ventricle. The 4th ventricle is located in the hindbrain. From the 4th ventricle the CSF may flow down the central canal of the spinal cord, or circulate in the subarachnoid space. The central canal of the spinal cord is in direct communication with the 4th ventricle.
A kidney cyst is a fluid-filled sac that grows in your kidneys, which are the bean-shaped organs that filter wastes out of your bloodstream to produce urine. You might have a single cyst on one kidney or many cysts on both kidneys. There are two types of cysts: simple cysts and polycystic kidney disease. Simple cysts are individual cysts that form on the kidneys. They have thin walls and contain a water-like fluid. Simple cysts donât damage the kidneys or affect their function. Polycystic kidney disease (PKD) is an inherited condition that causes many cysts to form on the kidneys. These cysts can damage the kidneys as they grow. Cysts are usually harmless.
Simple kidney cysts are usually small round sacs that have a thin wall and are filled with a watery fluid. As people get older, cysts can form on the surface or in the nephrons of the kidneys. They can range in size from a small pea to as large as a grapefruit.