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प्रश्न
If we happen to touch a hot object unknowingly, we immediately pull back our hand. What is this type of action known as?
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उत्तर
After touching a hot object unknowingly, the hand is automatically pulled back at once. This type of action is known as a reflex action.
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संबंधित प्रश्न
Briefly explain the following terms : Reflex action
Name two parts of the body which contain receptors of chemical stimuli.
Which part of the eye contains cells which are sensitive to light?
Which of the following helps in maintaining posture and balance of the human body?
One of the following controls the peristaltic movements of alimentary canal. This one is :
(a) cerebrum
(b) cerebellum
(c) pons
(d) medulla
The contraction of pupil of the eye in the presence of bright light is an example of :
(a) Voluntary reflex
(b) Spinal reflex
(c) Cerebral reflex
(d) Adrenal reflex
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.
State whether the following is simple reflex, conditioned reflex or neither of the two:
Blushing: ……………….
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
Explain the mechanism of reflex action with the help of a suitable diagram.
Define the following:
Reflex action
What is a reflex action?
Reflex action is controlled by the
State whether the following is
Cleaning
What type of reflex is the following?
Sweating in summer
Mention, if the following statement is True or False
Reflex action is a unit of nervous action
The reflex arc which is made up of one sensory and one motor neuron is ______
Reflex actions are mediated through ____________.
Given alongside is a partial diagrammatic representation of a certain phenomenon pertaining to the nervous system.
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- 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.
The diagram given below shows the internal structure of a spinal cord depicting a phenomenon. Study the diagram and answer the following questions.
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- Name the phenomenon shown in the figure and define the same.
- Identify the parts labelled as 1 and 2. Write one functional difference between these two.
- Name the bony protective covering and the membranous protective covering of the spinal cord.
- Label the guidelines 3 and 4.
- How is the labelled part 3 different from part 4 with respect to its composition (part of neuron)?
- Give the technical term for the point of contact between the two nerve cells.
- Name the fluid filled inside the central canal of spinal cord.
- Name the term used for a small gap between two neurons.
- Give one example of a neurotransmitter.
- Draw a neat diagram of a nerve cell and label the parts: Perikaryon, Node of Ranvier, Myelin sheath and Axon terminals.
