Chapter 13 : Nervous System

The CNS is largely made up of ...

• Sensory neurones

• Relay neurones

• Motor neurones

The CNS is only made up of the brain.

• True

• False

Answer explanation

CNS is made up of the brain and spinal cord.

In a reflex action, the nerve impulse does not pass through the brain.

• True

• False

Answer explanation

In a reflex action, the nerve impulse takes the shortest pathway known as the reflex arc from the receptor to the effector. It is possible the shortest route passes through the brain. It really depends where the stimulus is. E.g. if you knock your head on a sharp corner.

Which neurones are involved in a voluntary action?

• Sensory neurones

• Motor neurones

• Relay neurones

When your foot steps on a sharp object, it immediately withdraws due to a reflex action.

Is the following statement true or false? "In this event, nerve impulses are not sent to the brain."

• True

• False

Answer explanation

The fact that we sense pain shows that nerve impulses are sent to the brain.