Related Experiment Video

Updated: Aug 25, 2026

In vitro Measurements of Tracheal Constriction Using Mice
10:20

In vitro Measurements of Tracheal Constriction Using Mice

Published on: June 25, 2012

How perchlorate improves excitation-contraction coupling in skeletal muscle fibers

H C Lüttgau, G Gottschalk, L Kovács

    Biophysical Journal
    |August 1, 1983
    PubMed

    More Related Videos

    Ex Vivo Assessment of Contractility, Fatigability and Alternans in Isolated Skeletal Muscles14:02

    Ex Vivo Assessment of Contractility, Fatigability and Alternans in Isolated Skeletal Muscles

    Published on: November 1, 2012

    Levator Auris Longus Preparation for Examination of Mammalian Neuromuscular Transmission Under Voltage Clamp Conditions10:45

    Levator Auris Longus Preparation for Examination of Mammalian Neuromuscular Transmission Under Voltage Clamp Conditions

    Published on: May 5, 2018

    Related Concept Videos

    Muscle Contraction01:15

    Muscle Contraction

    Muscle Contraction01:10

    Muscle Contraction

    In skeletal muscles, acetylcholine is released by nerve terminals at the motor endplate—the point of synaptic communication between motor neurons and muscle fibers. The binding of acetylcholine to its receptors on the sarcolemma allows entry of sodium ions into the cell and triggers an action potential in the muscle cell. Thus, electrical signals from the brain are transmitted to the muscle. Subsequently, the enzyme acetylcholinesterase breaks down acetylcholine to prevent excessive muscle...
    Depolarizing Blockers: Mechanism of Action01:28

    Depolarizing Blockers: Mechanism of Action

    Depolarizing blockers act on skeletal muscle fibers' membranes and induce their depolarization. Most depolarizing blockers have two quaternary N+ atoms that bind the nicotinic acetylcholine receptors and cause neuromuscular blockade within minutes.
    Succinylcholine is the most commonly used depolarizing blocker. Chemically, it constitutes two molecules of acetylcholine joined together by an acetate methyl group. They act on the receptors in the same way as acetylcholine. Because succinylcholine...
    Excitation-Contraction Coupling in Skeletal Muscles01:20

    Excitation-Contraction Coupling in Skeletal Muscles

    Excitation-contraction coupling is a series of events that occur between generating an action potential and initiating a muscle contraction. It occurs at the triad, a structure found in skeletal muscle fibers that comprise a T-tubule and terminal cisternae of the sarcoplasmic reticulum on each side. These triads are visible in longitudinally sectioned muscle fibers. They are typically located at the A-I junction — the junction between the A and I bands of the sarcomere.
    When an action potential...
    Relaxation of Skeletal Muscles01:29

    Relaxation of Skeletal Muscles

    The period of muscle contraction primarily influences the duration of stimulation at the neuromuscular junction (NMJ), the presence of free calcium ions in the sarcoplasm, and the availability of energy or ATP to support contractions.
    When an action potential reaches the axon terminal, it depolarizes the membrane and opens voltage-gated sodium channels. Sodium ions enter the cell, further depolarizing the presynaptic membrane. This depolarization causes voltage-gated calcium channels to open.
    Motor Unit Stimulation01:20

    Motor Unit Stimulation

    When the neuron of a motor unit fires an action potential, it triggers a series of events, leading to a twitch contraction in the muscle fibers. The process of excitation-contraction coupling is crucial in relaying the action potential to the muscle fibers.
    The latent period of contraction marks the onset of excitation-contraction coupling, when the action potential propagates across the sarcolemma, preparing the muscle fibers for contraction. As the fibers enter the contraction phase, the...