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प्रश्न
What is a reflex action?
What is meant by Reflex action?
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उत्तर
Reflex action is a sudden, spontaneous, automatic, involuntary response to a stimulus.
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संबंधित प्रश्न
What is the role of the brain in reflex action?
Which part of the eye contains cells which are sensitive to light?
Our ______ system allows us to react to our surroundings. Information from receptors passes along ______ neurons to our brain. Our brain sends impulses along ______ neurons to our muscles.
Explain the difference between of the following pair of terms :
receptor and effector
A cell (or group of cells) in a sense organ which is sensitive to a particular type of stimulus is called :
(a) interceptor
(b) effector
(c) receptor
(d) acceptor
Which of the following are cerebral reflexes?
(i) a person pulls away his hand on touching a hot object
(ii) a person spits out immediately when a fly enters his mouth while talking
(iii) A person walking bare foot lifts his foot at once on stepping on to a nail
(iv) A person's pupil contracts at once in the presence of bright light
(a) (i) and (ii) (b) (ii) and (iii) (c) (iii) and (iv) (d) (ii) and (iv)
One of the following controls the peristaltic movements of alimentary canal. This one is :
(a) cerebrum
(b) cerebellum
(c) pons
(d) medulla
All the voluntary actions of our body are controlled by :
(a) cerebrum
(b) cerebellum
(c) pons
(d) medulla
P is a cell (or group of cells) in the human body which is sensitive to a particular type of stimulus and conveys the messages to CNS through nerves Q. On the other hand, R is a part of the human body which can respond to a stimulus according to the instructions sent from the CNS through nerves S.
(a) What is P? Name five organs which contain cells (or group of cells) like P.
(b) Name the nerves Q.
(c) What is R? Give two examples of R.
(d) Name nerves S.
(e) How do messages travel through the nerves Q and S?
Your are driving your bicycle at a fast speed. Suddenly, a small boy comes in front of your cycle and, without wasting any time in thinking, you immediately apply the brakes and accident is avoided. What name is given to such an action?
Differentiate between the following pair of terms:
Stimulus and impulse
Note the relationship between the first two words and suggest the suitable word/words for the fourth place.
Stimulus : Receptor :: Impulse : ______.
Note the relationship between the first two words and suggest the suitable word/words for the fourth place.
Receptor : Sensory nerve :: Motor nerve : ______.
What type of reflex is the following?
Knitting and swimming
What type of reflex is the following?
Blinking of the eye
The reflex arc which is made up of one sensory and one motor neuron is ______
Reflex actions are mediated through ____________.
If after cutting through dorsal root of a spinal nerve of a mammal, the associated receptor in skin was stimulated the animal would ______.
Why have reflex arcs evolved in animals?
