When we touch a hot plane unknowingly then this heat is sensed by a receptor P present in oyr fingers. The receptor triggers an impulse in neuron Q which transmits the message to an organ R which is a part of the central nervous system. Here the impulse is passed on to a neuron S which in turn passes it to a yet another neuron T. The neuron T passes the impulse to a tissue U in our arm. The tissue U then contracts and pulls or hand away from the hot plate.
(a) What is the name of (i) receptor P (ii) neuron Q, and (iii) organ R?
(b) What is (i) neuron S, and (ii) neuron T?
(c) Name the tissue U.
(d) What name is given to the phenomeon in which hand is pulled quickly from the hot plate?
(e) Name the effector in this whole process.

Answer

(a) (i) Thermoreceptor (ii) Sensory neuron (iii) Spinal cord (b) (i) Relay neuron (ii) Motor neuron (c) Muscle (d) Reflex action (e) Muscle (of arm)