Advertisements
Advertisements
प्रश्न
A person walks across a room in barefeet and puts his foot on a drawing pin lying on the floor. He lets out a cry. Explain what happens in his nervous system in bringing about this response.
Advertisements
उत्तर
It is an example of a reflex action. The stimulus in this example is pain which is felt by the foot on touching the drawing pin. This pain is sensed by a receptor in the foot. The receptor triggers an impulse to a sensory neuron which transmits the message to the spinal cord. Here, the impulse is passed on to a relay neuron which, in turn, passes it to a motor neuron. The motor neuron passes the impulse to a muscle in the foot. The muscle, then, contracts and pulls the foot away from the drawing pin.
APPEARS IN
संबंधित प्रश्न
Which part of the brain maintains posture and equilibrium of the body?
With the help of a neat and labelled diagram, describe reflex arc.
Explain the difference between of the following pair of terms :
cerebrum and cerebellum
Which of the following cannot be considered a receptor?
(a) ear
(b) nose
(c) muscle
(d) eye
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)
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.
what do we refer to in the nervous system when we say:
Natural and conditioned …………………
State whether the following is simple reflex, conditioned reflex or neither of the two.
Sudden application of brakes of the cycle on sighting an obstacle in front
State whether the following is simple reflex, conditioned reflex or neither of the two.
Lifting up a book
State whether the following is simple reflex, conditioned reflex or neither of the two.
Knitting without looking
State whether the following is
Playing on the Keyboard
What type of reflex is the following?
Formation of goose-pimples in cold weather.
Give Technical Term:
Response to a stimulus without the intervention of the will of an animal.
Mention, if the following statement is True or False
Reflex action involves brain
Mention, if the following statement is True or False
A reflex action is a spontaneous response to a stimulus.
The reflex arc which is made up of one sensory and one motor neuron is ______
Why have reflex arcs evolved in animals?
Categorise the following under stimulus and response.
Withdrawal of hand on touching a hot plate
