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प्रश्न
Define reflex arc. Give the flow chart of a spinal reflex arc.
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उत्तर
The path travelled by an impulse during a reflex action is called a reflex arc.
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संबंधित प्रश्न
Name the most important part of the human brain.
State whether coughing is a voluntary action or reflex action.
Name the function of cerebrum.
The part of brain which takes part in regulating respiration in the human body is :
(a) medulla
(b) pons
(c) cerebellum
(d) cerebrum
The gustatory receptors of our body are in one of the following organs. This organ is :
a) ear
(b) nose
(c) tongue
(d) skin
P is a cell (or group of cells) in the human body which is sensitive to a particular type of stimulus and conveys the messages to CNS through nerves Q. On the other hand, R is a part of the human body which can respond to a stimulus according to the instructions sent from the CNS through nerves S.
(a) What is P? Name five organs which contain cells (or group of cells) like P.
(b) Name the nerves Q.
(c) What is R? Give two examples of R.
(d) Name nerves S.
(e) How do messages travel through the nerves Q and S?
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.
Contraction of eye pupil
State whether the following is simple reflex, conditioned reflex or neither of the two.
Lifting up a book
What type of reflex is the following?
Blinking of the eye
Mention, if the following statement is True or False
Reflex action is a unit of nervous action
In reflex action, the reflex arc is formed by ______
Which one of the following is not a simple reflex?
Which of the following is not involved in Knee-jerk reflex?
Which sensory organ is involved in vertigo (sensation of oneself or objects spinning around)?
Categorise the following under stimulus and response.
Withdrawal of hand on touching a hot plate
Categorise the following under stimulus and response.
Pain in the eye if something falls into it.
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.
