Question

Put these steps in neuromuscular junction synaptic transmission and excitation-contraction coupling in chronological order. (Type the letters in the appropriate order with no spaces between them).

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

Answer- excitation- contraction coupling is a physiological process in which rle trical stimulus from neurons is converted into mechanical response in the form of muscle contraction by sacromere shortening. This conversion happens at the neuro muscular junction ( motor end plate).

steps in neuromuscular junction synaptic transmission and excitation-contraction coupling are:-

L. Vesicles containing acetylcholine fuse with nerve cell membrane

J. Acetylcholine receptors open and conduct Na+ ions.

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

G. An EPSP occurs in the muscle cell.

D. Depolarization of motoneuron axon terminal.

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

A. Ryanodine receptors open.

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

K. Ca2+ binds to Troponin.

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

H. Myosin heads go through the cross-bridge.

E. Ca2+ dissociates from troponin.