Question

The following statements about nerve metabolism excitation and conduction are true except
A. Nerve fiber can be excited under anaerobic conditions.
B. Nerve conduction proceeds in the absence of oxygen and the development of action potential does not depend on metabolism immediately.
C. In the absence of oxygen, an action potential can be generated and nerve conduction proceeds, but later, it fails as the Na+ pump cannot operate
D. At rest, the oxygen consumption in the brain is lesser than what is seen in a nerve.

Answer 1

Hint:
Neuronal metabolism consists of multiple steps that include submembrane glycolysis linked to membrane ion pumping aerobic glycolysis for pyruvate generation for aerobic metabolism, and NADH/ATP generation via the TCA cycle within mitochondria

Complete answer:
In terms of metabolism, the sympathetic nervous system is fundamental in controlling daily energy expenditure via the regulation of resting metabolic rate and initiation of thermogenesis in response to physiologically relevant stimuli, that is, changing energy states, food intake, carbohydrate consumption
Nerve fibers are also known as axons. It carries impulses away from cyton. In nerve metabolism excitation nerve fiber can be excited under the anaerobic condition which means in the absence of oxygen. The development of action potential does not depend upon metabolism as nerve conduction proceeds in anaerobic conditions. From this, we can conclude that action potential can be generated and nerve conduction proceeds in the absence of oxygen. But later stage it can proceeds further as the Na⁺ pump cannot operate in this condition.
Hence the correct answer is At rest, the oxygen consumption in the brain is lesser than what is seen in a nerve.

Option ‘D’ is correct

Note:
It is a single, unbranched cylindrical projection that arises from the cyton. The axon is covered with a myelin sheath and it is fatty in nature. The axon is covered with a myelin sheath and it is fatty in nature. Generally, the neurons have one axon that can range in size between 0.1 mm to over 3 feet.