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प्रश्न
Briefly explain the following terms : Reflex action
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उत्तर
Reflex action:
A reflex action is an involuntary and quick response of the body initiated because of a stimulus. The commands for a reflex action originate from the spinal cord.
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संबंधित प्रश्न
The diagram given below shows the internal structure of a spinal cord depicting a phenomena. Study the diagram and answer the questions:
- Name the phenomenon that is depicted in the diagram. Define the phenomenon.
- Give the technical term for the point of contact between the two nerve cells.
- Name the parts numbered 1, 2 and 3.
- How does the arrangement of neurons in the spinal cord differ from that of the brain?
- Mention two ways by which the spinal cord is protected in our body.
State whether coughing is a voluntary action or reflex action.
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)
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
State whether the following is
Sneezing
What type of reflex is the following?
Sweating in summer
What will you do if someone pricks your hand with a needle? Elucidate the pathway of response with a neat labelled diagram.
How is the mode of action in beating of the heart different from reflex actions? Give four examples.
Categorise the following under stimulus and response.
Withdrawal of hand on touching a hot plate
