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प्रश्न
What is a reflex action?
What is meant by Reflex action?
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उत्तर १
Reflex action is a sudden, spontaneous, automatic, involuntary response to a stimulus.
उत्तर २
Reflex action is an autonomic, quick and involuntary action in the body brought about by a stimulus.
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संबंधित प्रश्न
Briefly explain the following terms : Reflex action
Which of the following is not a natural reflex action?
A. Knee-jerk
B. Blinking of eyes due to strong light
C. Salivation at the sight of food
D. Sneezing when any irritant enters the nose
State one function each of cerebellum and pons.
Which part of the eye contains cells which are sensitive to light?
Fill in the following blanks with suitable words :
Our.............system allows us to react to our surroundings. Information from receptors passes along...........neurons to our brain. Our brain sends impulses along..........neurons to our muscles.
Write the names of the regions in hindbrain. Give one function of each region.
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)
The involuntary actions in the body are controlled by :
(a) medulla in forebrain
(b)medulla in hindbrain
(c) medulla in spinal cord
(d) medulla in midbrain
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
The olfactory receptors in humans are located in :
(a) eyes
(b) tongue
(c) ears
(d) nose
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?
State whether the following is simple reflex, conditioned reflex or neither of the two.
Blushing
State whether the following is
Constriction of pupil
State whether the following is simple reflex, conditioned reflex or neither of the two.
Knitting without looking
What type of reflex is the following?
Formation of goose-pimples in cold weather.
A change in the environment that causes an animal to react is called ______.
Which one of the following is not a simple reflex?
Which of the following is not involved in Knee-jerk reflex?
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
