Q49.2-2CC - Campbell Biology

Question

People who are inebriated have difficulty touching their nose with their eyes closed. Which brain region does this observation indicate is one of those impaired by alcohol?

Step-by-Step Solution

Answer

The cerebellum is the brain region that gets affected if a person is drunk or intoxicated by alcohol. The cerebellum is the small brain that controls the balance, posture, and coordination of the body.

Step 1: Person impaired by alcohol

Alcohol intoxication is a condition that occurs when a person consumes too much alcohol for a brief period. During alcohol intoxication a person's mental and physical abilities are impaired.

GABA (gamma-aminobutyric acid), a naturally-occurring neurotransmitter in the body, is amplified by alcohol. Neurotransmitters are chemicals that chemically link messages from one nerve to the next.

This signal flow in the brain is reduced by an inhibitory neurotransmitter (alcohol).

Step 2: Cerebellum in the brain

The cerebellum is the tiny region located between the brain stem and the cerebrum at the backside of the brain. The primary function of the cerebellum is to provide posture, balance, and maintain the standing and walking positions.

Step 3: Effect of alcohol on the brain region

In an alcohol-intoxicated person, the cerebellum of the brain is affected by extreme alcohol consumption. The cerebellum that controls speech, posture, and balance is affected when someone takes alcohol in high concentration. 

Thus, the alcohol-impaired person cannot touch their nose with their eyes closed as there is no control on the coordination of the body because of the alcohol effect on the cerebellum of the brain.