Question

Diagram based question:

1. Fill in the blanks in fig. A: (i), (ii), (iii) and (iv).

2. Which action does the figure depict?

Answer 1

1. The labelling for the fig. A:

1. Receptor(skin).
2. Sensory neuron.
3. Motor neuron.
4. Effector(muscle or gland).

2. The action depicted in the figure is “reflex action”:

1. Reflex action is a sudden and involuntary response against any external stimulus.
2. It occurs due to the nervous system that comprises neurons and the pathway through which reflex action takes place is called a reflex arc.
3. In this process, the signals are received by the receptors that are present in the skin or any sensory organ.
4. Further the information is sent to the central nervous system(CNS) by the sensory neurons via the spinal cord.
5. The signals are processed in the CNS and sent toward the effector (muscles) by the motor neuron.