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प्रश्न
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
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उत्तर
The pathway taken by nerve impulses in a reflex action is called a reflex arc. It is an automatic response to a stimulus. When a stimulus is given to a receptor, the receptors produce an impulse in the sensory fibre. The sensory fibre carries this message in the form of an electrical stimulus across the synapse. From the synapse, the impulse travels in the motor fibre and stimulates the effector organ to produce the desired response.
The correct order for a simple reflex arc is:
(b) →(d) → (a) → (c).
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संबंधित प्रश्न
What is the role of the brain in reflex action?
With the help of a neat and labelled diagram, describe reflex arc.
Briefly explain the following terms : Reflex action
The diagram given below shows the internal structure of a spinal cord depicting a phenomenon. Study the diagram and answer the questions:
1) Name the phenomenon that is depicted in the diagram. Define the phenomenon.
2) Give the technical term for the point of contact between the two nerve cells.
3) Name the parts numbered 1, 2 and 3.
4) How does the arrangement of neurons in the spinal cord differ from that of the brain?
5) Mention two ways by which the spinal cord is protected in our body.
Name the most important part of the human brain.
State one function each of cerebellum and pons.
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.
Which of the following statements are true?
(i) sudden action in response to something in the environment is called reflex action
(ii) sensory neurons carry electrical signals from spinal cord to muscles in a reflex action
(iii) motor neurons carry signals from receptors to spinal cord in a reflex action
(iv) the pathway of transmitting signals from a receptor to a muscle is a reflex action
Differentiate between the following pair of terms:
Stimulus and impulse
With the help of suitable example, describe reflex action.
State whether the following is simple reflex, conditioned reflex or neither of the two:
Knitting without looking: …………………..
Give one example of a conditioned reflex in your own life.
State whether the following is simple reflex, conditioned reflex or neither of the two.
Lifting up a book
State whether the following is
The sudden application of brakes without thinking
What type of reflex is the following?
Blinking of the eye
Complete the following sentence with appropriate Word
A reflex arc in man is best described as movement of stimuli from:
A change in the environment that causes an animal to react is called ______.
Why have reflex arcs evolved in animals?
Given alongside is a partial diagrammatic representation of a certain phenomenon pertaining to the nervous system.
 |
- Name the parts numbered 1-7.
- Name the phenomenon that the diagram depicts and define it.
- Give the technical term for the point of contact between two nerve cells.
- Name the parts not shown in the diagram that should be included to complete the pathway of the phenomenon.
State whether the following is simple reflex, conditioned reflex or neither of the two.
Sneezing
