Answer :
The three areas in the brain that are not isolated from the general circulation by the blood-brain barrier (BBB) are the choroid plexus, the area postrema, and the pineal gland.
The choroid plexus is a network of blood vessels and connective tissue in the brain that produces cerebrospinal fluid (CSF). CSF is a clear, watery fluid that surrounds and cushions the brain and spinal cord. The choroid plexus is located in the ventricles of the brain, which are cavities filled with CSF.
The area postrema is a small region of the brain located at the base of the fourth ventricle. The area postrema is not surrounded by the BBB. This allows it to detect toxins and other substances in the blood and send signals to the brain to induce vomiting.
The pineal gland is a small, cone-shaped gland located in the center of the brain. The pineal gland produces melatonin, a hormone that regulates sleep and wakefulness. The pineal gland is not surrounded by the BBB.
To learn more about cerebrospinal fluid (CSF) visit : https://brainly.com/question/4466147
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