CBSE Class 10 Answered

1. The receptor at the end of a sensory neuron reacts to a stimulus.

2. The sensory neuron conducts nerve impulses along an afferent pathway towards the central nervous system (CNS).

3. The integration center consists of one or more synapses in the CNS.

4. A motor (efferent) neuron conducts a nerve impulse along an efferent pathway from the integration center to an effector.

5. An effector responds to the efferent impulses by contracting (if the effector is a muscle fiber) or secreting a product (if the effector is a gland).

Working: The sensory neuron (such as a pain receptor in the skin) detects the stimuli and sends a signal towards the CNS. This sensory neuron synapses with a motor neuron which innervates the effector tissue (such as skeletal muscle to pull away from the painful stimuli). This is the simplest reflex arc.