Question

Identify a, b, c, d, e and / of reflex arc

• A. a-stimulus, b-receptor, c-sensory nerve, d motor nerve, eeffector, f-response
• B. a-stimulus, b-effector, c-sensory nerve, dmotor nerve, e-receptor, f-response
• C. a-stimulus, b-effector, c-motor nerve, d-sensory nerve, e-receptor, f-response
• D. a-stimulus, b-receptor, c-motor nerve, d-sensory nerve, e-effector, f-response

Answer 1

The correct option is A a-stimulus, b-receptor, c-sensory nerve, d motor nerve, eeffector, f-response

The nervous system detects and responds to changes inside and outside the body.

(i) Receptors are structures at the ends of the nerve fibres that detect changes in the environment (stimuli), and turn them into electrical impulses. These receptors may be specialised sense organs like ear, eye and skin.

(ii) Sensory neurons carry electrical signals (impulses) from receptors or sense organs to the CNS (Central Nervous System). They are also called afferent neurons.

(iii) The central nervous system consists of the brain and the spinal cord.

(iv) Motor neurons carry impulses from the CNS to effector organs. They are also called efferent neurons.

(v) Effectors are muscles or glands which work in response to the stimulus received from the motor neurons.

So, the correct pathway is - Receptor -Sensory Neuron-Spinal cord-Motor neuron-Effector-Response