Question

Which is the example of conditioned reflex?
A. Eyes closed when anything enters into it.
B. Hand took up when pierced with a needle.
C. Salivation in a hungry dog in response to ringing of a bell.
D. Digested food goes forward in the alimentary canal.

Answer 1

Hint: A reflex is an involuntary or voluntary action that our body does in response to something without even thinking about it.
For example: when light acts as stimulus, the pupil of the eye changes in size.
Knee jerk reflex in response to a blow or someone stamping the leg.

Complete answer:
In order to solve this question we need to know about reflexes and type of reflexes.
Reflex: It is an involuntary and voluntary action that our body responds to something without even thinking of it.
It is of two types:
- Conditioned reflex.
- Unconditioned reflex.

The whole process of response to a peripheral nervous stimulation, which occurs involuntarily i.e., without effort or thought and requires the involvement of a part of the central nervous system and is known as reflex action.
Reflex pathway consists of least one afferent neuron and one efferent neuron arranged in series.

Conditioned reflex: conditioned reflex is the stimulus which is associated with another stimulus and response is generated.
For example: Salivation in a hungry dog in response to ringing a bell.

Unconditioned reflex: Unconditioned reflex is the response obtained on a given stimulus.
For example: Eyes closed when anything enters into it, Hand taken away when pierced with a needle, and digested food goes forward in an alimentary canal.

So, the correct option is option c. salivation in a hungry dog in response to a ringing a bell.

Note: A nerve impulse is transmitted from one neuron to another through a junction called synapses.
Synapse is formed by membranes of a presynaptic neuron and a postsynaptic neuron which may or may not be separated by a synaptic cleft.
There are two types of synapses, namely, electrical synapses and chemical synapses.