After drinking alcohol, a person walks clumsily because, the alcohol affects his

Alcohol consumption leads to clumsy walking and loss of balance because it primarily affects the cerebellum, a part of the hind-brain [1]. The cerebellum is responsible for the precision of voluntary actions and maintaining the posture and equilibrium of the body [3]. Alcohol acts as a central nervous system depressant, slowing down neural communication. Specifically, it impairs the cerebellum's ability to coordinate muscle movements, leading to symptoms such as ataxia, which is characterized by gait disturbances, irregular steps, and pronounced swaying. While the medulla oblongata controls vital involuntary functions like breathing and heart rate [2], and the cerebrum handles higher-order cognitive processes, the specific impairment of motor coordination and balance observed in 'clumsy walking' is a direct result of cerebellar dysfunction [4]. Chronic alcohol use can even lead to permanent cerebellar atrophy.

Sources

1. [1] Science , class X (NCERT 2025 ed.) > Chapter 6: Control and Coordination > 6.1.2 Human Brain > p. 104
2. [3] https://oasas.ny.gov/system/files/documents/2019/08/The_Brain.pdf
3. [2] Science , class X (NCERT 2025 ed.) > Chapter 6: Control and Coordination > QUESTIONS > p. 105
4. [4] https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/alcohol-related-brain-impairment