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प्रश्न
What is a reflex action? Explain with the help of an example.
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उत्तर
Reflex action is a rapid and automatic response to a stimulus. It is not under the voluntary control of the brain. For example, if we unknowingly touch a hot plate, we immediately move our hand away from it.
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संबंधित प्रश्न
How do we detect the smell of an agarbatti (incense stick)?
Which of the following is not a natural reflex action?
A. Knee-jerk
B. Blinking of eyes due to strong light
C. Salivation at the sight of food
D. Sneezing when any irritant enters the nose
Name the most important part of the human brain.
Give three examples of reflex actions.
Explain the difference between of the following pair of terms :
receptor and effector
Cerbellum, medulla and pons are the parts of :
(a) mid-brain
(b) hind-brain
(c) forebrain
(d) spinal cord
Which of the following statements is correct about receptors?
One of the following gives the correct sequence of the components in a reflex arc. This is:
The gustatory receptors of our body are in one of the following organs. This organ is :
a) ear
(b) nose
(c) tongue
(d) skin
The olfactory receptors in humans are located in :
(a) eyes
(b) tongue
(c) ears
(d) nose
When we touch a hot plate unknowingly, then this heat is sensed by a receptor P present in our fingers. The receptor triggers and 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 our 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 phenomenon in which hand is pulled away quickly from the hot plate?
(e) Name the effector in this whole process.
Write down the following activities in the correct order for a simple reflex arc:
(a) impulse travels in the motor fibre
(b) impulse travels in the sensory fibre
(c) effector organ stimulated
(d) impulse crosses the synapse
Differentiate between the following pair of terms:
Stimulus and impulse
Complete the following statement by choosing the correct alternative from the choice given in bracker:
Reflex action is controlled by
(i) brain (ii) spinal cord
(iii) autonomic (iii) peripheral nervous system
Define the following:
Reflex action
State whether the following is simple reflex, conditioned reflex or neither of the two.
Blushing
Give Technical Term:
Response to a stimulus without the intervention of the will of an animal.
A change in the environment that causes an animal to react is called ______.
Reflex actions are mediated through ____________.
Which sensory organ is involved in vertigo (sensation of oneself or objects spinning around)?
