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Which of the following statements about ...

Which of the following statements about the mechanism of muscle contraction are correct ?
(i) Acetylcholine is released when the neural signal reaches the motor end plate.
Muscle contraction is initiated by a signal sent by CNS via sensory neuron.
(iii) During muscle contraction, isotropic band gets elongated (iv) Repeated activation of the muscles can lead to lactic acid accumulation.

A

(i) and (iv)

B

(i) and (iii)

C

(ii) and (iii)

D

(i), (ii) and (iii)

Text Solution

Verified by Experts

The correct Answer is:
A
Muscle contraction is initiated by a signal sent by CNS via a motor neuron. During muscle contraction, isotropic band gets shortened.
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Which statements about muscle contractions are true (i) Acetylcholine is released when neural signal reaches motor end plate (ii) Muscle contraction is initiated by a signal sent by CNS via a sensory neuron (iii) During muscle contraction , isotropic band gets elongated (iv) Repeated activation of the muscle can lead to lactic acid accumulation .

Which of the statements about the mechanism of muscle contraction are corrcet (I) Acetylcholine is released when the neural signal raches the motor end plate (II) Muscle contration is initiated by a singnal sent by CNS via a sensory neuron (III) During muscle contration, isotropic band gets elongated (IV) Repeated activation of the muscles can be lead to lactic acid eccumulation

Which of the following statements given below are true with reference to muscle contraction. I. Neurotransmitter acetycholine is released as nerve impulse reaches the end of axon and binds to receptor sites of motor end plate. II. Action potential passes from motor end plate over sarcoplasmic and then into the T-tubules and sarcoplasmic reticulum. III. Calcium ion are released into the sarcoplasm bind to troponin, causing a change in its shape and position. IV. Myosin cross bridges are able to bind to exposed active sites of actin. Choose the correct option.

The steps involved in the mechanism of muscle contraction are given below. Arrange the steps in proper sequential order and select the correct option. I. Release of calcium ions in the sarcoplasm. II. Signal sent by the CNS via a motor neuron. III. Binding of calcium with a subunit of troponin on actin filaments. IV. Generation of the action potential in the sarcolemma. V. Binding of myosin head to the exposed active sites on actin to form a cross-bridge. VI. Inward pulling of ‘Z’ line attached to actin causing shortening of the sarcomere. VII. Pulling of the attached actin filaments towards the centre of 'A' band. VIII. Release of neurotransmitter acetylcholine and generation of the action potential in the sarcolemma.

Read the following statements is context to muscle tissue and choose the correct answer . (i) Excessive exercise results in anaerobic Respiration and forms lactic acid . (ii) As per sliding filament theory of muscle contraction, the filament that moves to shorten a muscule is actin . (iii) The muscles primarily involved in locomotion is striated muscles .

Go through the following statements During muscle contraction, the width of A-band remains constant while I-band shortens. During muscle contraction, the Ca^(2+) released from the SR bind to the troponin component of thin filament The process of muscle contraction is faster in smooth muscle as they have a well developed sarcoplasmic reticulum. The red muscle fibres have abundant mitochondria, low glycogen and poorly formed sarcoplasmic reticulum.

Which of the following staements are true? (i) Sudden action in response to something in the enviornment is called reflex action (ii) Sensory neurons carry signals from spinal cord to muscles. (iii) Motor neurons carry signals from spinal cord to muscles. (iv) The path through which signals are transmitted from a receptor to a muscle or a gland is called reflex arc.

Which of the following statements are true? (i) sudden action in respons 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 transmittin signals from a receptor to a muscle is a reflex action

Which of the following sequenes is correct to intite inspiration ? (i) the contraction of external intercostal muscles raises the ribs and sternum (ii) Volume of thorax increases in the dorso-ventral axis (iii) intrapulmonary pressure decreases (iv) Diaphragm contraction (v) Air rushes into lungs (vi) Volume of thorax increases in the anterior-posterior axis

NCERT FINGERTIPS-LOCOMOTION AND MOVEMENT-Locomotion And Movement
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  2. Consider the following statements each with one or two blanks. (i) ...

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  3. Which of the following statements about the mechanism of muscle contra...

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  4. The slow twitch muscle fibre which are rich in myoglobin and have abun...

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  5. Identify from the following list, the characteristics of red muscles (...

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  6. Myoglobin is present in

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  7. Which of the following is a source of energy for muscle contraction ?

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  8. The protien whose removal enables myosin to bind actin in smooth muscl...

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  9. During muscle contraction, actin and myosin ffrom

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  10. Which of the following ions help in muscle contraction ?

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  11. If a stimulus, several times greater than the threshold stimulus, is p...

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  12. Which of the following is incorrect regarding muscle contraction?

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  13. Upon stimulation of skeletal muscles, calcium is immediately made avai...

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  14. In the resting muscle fibre, tropomysin partially covers

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  17. Which of the following is a bone of skull?

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  18. Cranium of human contains

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  19. How many bones form the skeleton of the face ?

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