Question

Put these steps in neuromuscular junction synaptic transmission and excitation-contraction coupling in chronological order.

A. Ryanodine receptors open

B. Voltage-gated Na+ channels open in the muscle cell membrane near the neuromuscular junction

C. Tropomyosin rotates into the groove of the thin filament (out of the way of the myosin binding site)

D. Depolarization of motoneuron axon terminal

E. Ca2+ dissociates from troponin

F. [Ca2+] rises in the muscle cell cytoplasm

G. An EPSP occurs in the muscle cell

H. Myosin heads go through the cross-bridge cycle and hydrolyze ATP

I. An action potential is conducted along the T-tubule

J. Acetylcholine receptors open and conduct Na+ ions

K. Ca2+ binds to Troponin

L. Vesicles containing acetylcholine fuse with nerve cell membrane

Answer 1

Steps in order are mentioned below. Hope this will will help.

These all steps are involved in excitation contraction coupling. In love release of neurotransmitter in to synaptic cleft and binds to motor end plate of skeletal muscle. And followed by the reskse of calcium and muscle contraction.

1) D. Depolarization of motoneuron axonal terminal

2) L. Vesicles containing acetylcholine fuse with nerve cell membrane

3) J. ACetylcholine receptors open and conduct Na+ ions.

4) G. An EPSP occur in muscle cell.

5) B. Voltage-gated Na+ channels open in the muscle cell membrane near the neuromuscular junction.

6) I. An action potential is conducted along with T tubules.

7) A. Ryanodine receptor opens.

8) F. Ca rises in the cytoplasm.

9) K. Calcium binds to troponin.

10.) C. Tropomyosin rotates into the groove of the thin filament (out of the way of the myosin binding site)

11). H. Myosin heads go through the cross-bridge cycle and hydrolyze ATP

12) E. Calcium dissociate from troponin.