Question

In thinking and response to external stimulus the brain take time about
a. Less than ${\text{1/10}}\;{\text{th}}$ second
b. ${\text{1/10}}\;{\text{th}}$ second
c. More than ${\text{1/10}}\;{\text{th}}$ second
d. About $1$ second

Answer 1

Hint: Human nervous system is highly developed. The external stimulus leads to generation of impulse. Sensory neurons conduct this impulse and response is given by the organs on receiving the answer given by the brain. It is considered that the brain and the nervous system take a fraction of a second to give the response.

Complete answer:
The human nervous system is highly developed. The sum of all the tissues that record and distribute information within a person, and do this by electrical and chemical means is called the nervous system.

The nervous system has two different parts - Central and peripheral.
The central part of the nervous system consists of the brain and spinal cord. The combination of these two is called the central nervous system (CNS). The peripheral part of the nervous system is at the outer part of the Central Nervous System. The peripheral nervous system is used to transmit the information between the CNS and the rest of the body in the back and forth manner.
Thus, in thinking and responding to external stimuli the brain takes time about ${\text{1/10}}\;{\text{th}}$ second.

The time taken by the brain and the nervous system to respond is considered in fraction of a second.
Hence, the correct answer is option (B).

Note: Human nervous system contains around 10 billion nerve cells. These neurons are known for the basic building blocks of the nervous system. Nerve cell body and various extensions from the cell body consist in the neurons.