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प्रश्न
What are reflex actions? Give two examples. Explain a reflex arc.
उत्तर
Reflex action is a sudden, spontaneous, automatic, involuntary response to the stimulus. It is an involuntary response as it is carried out without any conscious effort by the brain. The path along which the action is carried out is called the reflex arc.
Examples-
- Sudden withdrawal of hand while it comes in contact with a hot object.
- Narrowing of the pupil on exposure to bright light.
Reflex arc - The pathway of the nerve impulses involved during a reflex action constitutes the reflex arc. When there is a stimulus, it is first perceived by receptors present on the skin that send the stimulus in the form of an impulse, from the sensory neuron to the spinal cord. The spinal cord interprets the stimulus and sends the impulse to the motor neurons. The motor neurons in turn stimulate the effectors or muscles to respond to the stimulus.
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संबंधित प्रश्न
A part of the body which responds to the instructions sent from the nervous system is called ____________.
Reflex arc is formed by:
Which of the following statements are true?
- Sudden action in response to something in the environment is called reflex action
- Sensory neurons carry signals from spinal cord to muscles
- Motor neurons carry signals from receptors to spinal cord
- The path through which signals are transmitted from a receptor to a muscle or a gland is called reflex arc
Junction between two neurons is called
Label the parts (a), (b), (c) and (d) and show the direction of flow of electrical signals in the given figure.
From where the following nerves arise.
Auditory nerve
Which one is NOT a reflex action?
Route of reflex arc is ______.
Sensory nerve of a reflex arc carries information from the receptor cells to the ______.
Arrange and rewrite the terms in the group in the correct order to be in a logical sequence beginning with the term that is underlined:
Receptor, Response, Effector, Spinal Cord.
