Christopher was cycling downhill at a good speed when a cat suddenly came in front of him out of nowhere. Before he could even think, he hit the brake and stopped just in time. No harm was done to the cat. Later he wondered how his body reacted so quickly even though he didn't make a conscious decision.

(a) What is the term used for such an immediate, automatic action?

(b) Which part of the central nervous system controls this action?

(c) Which major organ of the nervous system is not involved in such actions?

(d) Enlist the correct pathway of the action through which Christopher's body responded so quickly.

(a) The immediate and automatic action is called a reflex action.

(b) This action is mainly controlled by the spinal cord.

(c) The brain (especially cerebrum) is not directly involved in controlling reflex actions.

(d) The correct pathway of the action through which Christopher's body responded so quickly is :

Stimulus → Receptor → Sensory neuron → Spinal cord → Motor neuron → Effector → Response