Question

Brain depends on blood for the supply of
(a) Oxygen and ATP
(b) Oxygen and electrolytes
(c) Oxygen and glucose
(d) ATP and glucose

Answer 1

Hint: The movement of blood through a network of cerebral veins and arteries is called cerebral circulation. The brain is a very sensitive organ and it will suffer damage in the case of stoppage of blood flow from the network of cerebral arteries and veins.

Complete Answer:
Approximately 750 milliliters of blood is circulated through the network of veins and arteries of the brain in a minute. This is the rate of cerebral blood flow in a healthy human adult. The rate of cerebral circulation is approximately $15\%$ of the cardiac output of the body in a healthy adult.
The cerebral circulatory network has an internal adaptive mechanism in the form of autoregulation of the blood vessels which provides the brain with sufficient amounts of blood for it to function with minimal damage.
The cerebral arteries circulate oxygenated blood, glucose and various nutrients to the brain. The cerebral veins carry the blood consumed by the brain back to the heart where the deposited carbon dioxide, lactic acid and various metabolic products are removed.

Therefore the brain depends on blood for the supply of oxygen and glucose. Hence, the correct answer is (c) Oxygen and glucose.

Note:
The failure of internal adaptive mechanisms like autoregulation may result in a stroke. Severe changes in the gravitational forces exhibited on the body may result in the impairment of the cerebral circulatory network. This impairment may also lead to the loss of normal functioning of the brain and may lead to life-threatening, serious consequences.