The basic process of excitatory contractile coupling of skeletal muscle cells is briefly described

1.Action potentials on the sarcosa propagate along the sarcoma and the T ductal membrane, while activating L-type calcium channels on the T membrane of the sarcosa.

2.Activation of L-type calcium channels through allosteric action (in skeletal muscle) or influx of activated calcium release channels releases Ca2+ in JSR into the cell, and the concentration of Ca2+ in the cytosol increases from resting levels to 1-10umol L

3.Elevated Ca2+ concentrations in the cytosol promote TNC to bind to Ca2+ and trigger muscle contraction.

4.When the concentration of Ca2+ in the cytosol increases, the calcium pump on the LSR membrane is activated, and the calcium pump will enter the Ca2+** in the cytoplasm into the sarcoplasmic reticulum, thereby reducing the concentration of Ca2+ in the cytosol and relaxing the muscle.

The key steps of the skeletal muscle excitation-contraction coupling process are:

a.Electrical excitation is transmitted through the longitudinal duct to the deep and wide royal part of the myocyte.

b.The longitudinal membrane generates an action potential.

c.The permeability of the longitudinal terminal cistern to Ca2+ is increased.

d.The inverse concentration difference of Ca2+ in the terminal cisterna of the longitudinal canal enters the sarcoplasm.

Binds to troponin subunit T.

Correct answer: c

The excitation-contraction coupling process and the principle of contraction and relaxation of skeletal muscle are as follows

The muscle membrane action potential dome is transmitted to the cell through the transverse tube Information is transmitted to the terminal pool of the sarcoplasmic reticulum through the triplet structure The terminal cistern releases Ca ions increase in the sarcoplasm Ca ions bind to troponin Troponin configuration changes Troponin configuration changes Exposure of the transverse bridge binding site on myofiin (i.e., myokinetic protein) Cross bridge binds to myofin Activates ATPase and breaks down ATP for energy The transverse bridge twists and drags the thin myosame to slide towards the M-line Shortening of the sarcomere Muscle contraction.

Loss of sarcoplasmic action potential Calcium pump transport on sarcoplasmic reticulum, Ca ions are pumped back to sarcoplasmic reticulum Ca ions in sarcoplasma decrease Ca ions and troponin separation Troponin configuration restoration Promyoscodild collapse white reduction Occlusion on myogenic gland Blocking of transverse bridge binding on myogenic fibrous Prevents transverse bridge from binding to myofin Thin muscle filaments slip out of thick myosamores, and sarcomeres return to their original position Muscle relaxation. Increased Ca ions in the sarcoplasm Ca ions bind to troponin Troponin configuration changes Troponin configuration changes Exposure of transverse bridge binding sites on myogenic (i.e., actin) Transverse bridge binds to myofin Activates ATPase and breaks down ATP for energy Cross bridge twisting, dragging thin muscle filaments toward the M-line Shortening of the sarcomere Muscle contraction.

Loss of sarcoplasmic action potential Calcium pump transport on sarcoplasmic reticulum, Ca ions are pumped back to sarcoplasmic reticulum Ca ions decrease in sarcoplasma Ca ions separate from troponin Troponin configuration restoration Promyosin repositioning Obscuration of transverse bridge binding on myoliin Prevents transverse bridge binding to myocin Thin muscle filaments slide out of thick myomefilaments, and sarcomeres return to their original position Muscle relaxation.

The key substance for skeletal muscle rejuvenation-contractile coupling is ()aSodium ions.

b.Magnesium ions.

c.Potassium ions.

d.Calcium ions (correct answer).

e.Chloride ions.

Answer]: Excitation-contraction coupling consists of at least three main steps: electrical excitation is transmitted deep into the muscle cells through the transverse duct system; information transmission at the triplet structure; Sarcoplasmic reticulum (i.e., longitudinal duct culture system) <> CA

Release and reaccumulation. In the connecting sarcoplasmic reticulum or terminal cistern, the CA <> is thousands to tens of thousands of times higher than that in the precytoplasmic mesomodel. Ryanodine receptor activation results in the release of Ca2 into the cytosol in a separatorial process. Whereas CA in the cytoplasm <>

Elevated concentrations activate a calcium pump on the LSR membrane, which inversely follows the Ca<> concentration gradient in the cytosol into the sarcoplasmic reticulum. Therefore, C.

The excitation-contraction coupling process and the principle of contraction and relaxation of skeletal muscle are as follows

The action potential of the muscle membrane is transmitted to the cell through the transverse tube Information is transmitted to the terminal cistern of the sarcoplasmic reticulum through the triplet structure The terminal cistern releases Ca increases Ca in the sarcoplasm Ca binds to troponin Troponin configuration changes Troponin configuration changes Exposure of transverse bridge binding sites on myfibrin (i.e., actin) Transverse bridge binds to myofiin Activates ATPase and breaks down ATP for energy Transverse bridge twists, drags the thin muscle filaments to slide towards the M-line Shortening of the sarcomere Muscle contraction.

Loss of sarcoplasmic action potential Calcium pump transport on sarcoplasmic reticulum, Ca is pumped back to sarcoplasmic reticulum Ca decreases Ca separation from troponin Troponin configuration restoration Troponin repositioning Obscuration of transverse bridge binding on myavilin Prevents transverse bridge binding to myofin Thin muscle filaments slip out of the thick myomegranament and sarcomeliform cleft returns to its original position Muscle relaxation. Increased CA in the sarcoplasm CA binds to troponin Troponin configuration changes Styliston configuration changes Exposure of transverse bridge binding sites on myogenic (i.e., actin) Transverse bridge binds to myofin Activates ATPase and breaks down ATP for energy The transverse bridge twists and drags the thin muscle filaments toward the m-line Shortening of the sarcomere Muscle contraction.

Loss of sarcoplasmic action potential Calcium pump transport on sarcoplasmic reticulum and Ca is pumped back to sarcoplasmic reticulum Ca decreases in sarcoplasm Separation of Ca from troponin Troponin configuration restoration Reduction of troponin Obscuration of transverse bridge junction on myoliin Prevents transverse bridge binding to myofin Thin muscle filaments slip out of thick myomefilaments, and sarcomeres or scatters return to their original position Muscle relaxation.

Answer]: Daji C

The coupling factor of excitator-contraction coupling in skeletal muscle is Ca2+. Master the knowledge points of "contraction function of circular skeletal muscle".

a.The concentration of Ca2+ in the sarcoplasm decreases rapidly, leading to the dissociation of calcineurin and the Ca2+ it binds.

b.The information transmission at the triple pipe structure leads to the release of Ca2+ in the final pool.

c.Ca2+ in sarcoplasm binds to troponin.

d.Electrical excitation travels through the transverse duct system to the interior of the muscle cell.

Correct Answer: a