Related Experiment Video

Updated: Jul 16, 2026

Measurement of Maximum Isometric Force Generated by Permeabilized Skeletal Muscle Fibers
11:30

Measurement of Maximum Isometric Force Generated by Permeabilized Skeletal Muscle Fibers

Published on: June 16, 2015

Effects of a ten-second maximum voluntary contraction on regulatory myosin light-chain phosphorylation and dynamic

J Chadwick Smith1, Andrew C Fry

  • 1Department of Neurobiology and Anatomy, Wake Forest University, Winston-Salem, North Carolina 27157, USA. chadsmit@wfubmc.edu

Journal of Strength and Conditioning Research
|February 23, 2007
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

In Vivo Measurement of Hindlimb Dorsiflexor Isometric Torque from Pig09:41

In Vivo Measurement of Hindlimb Dorsiflexor Isometric Torque from Pig

Published on: September 3, 2021

Related Concept Videos

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...
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.
Smooth Muscle Contraction01:25

Smooth Muscle Contraction

Smooth muscle contraction is a complex process vital for various bodily functions, from maintaining blood vessel tension to facilitating the movement of food through the digestive tract. Unlike striated muscles, smooth muscle contraction begins more slowly and lasts longer.
The onset of contraction is triggered by an increase in calcium ions within the sarcoplasm, similar to the process in striated muscle. However, smooth muscles have a relatively smaller reservoir of the sarcoplasmic...
Energy Supply for Muscle Contraction01:25

Energy Supply for Muscle Contraction

Skeletal muscle fibers have the unique ability to switch between rest and contraction states, using different sources of ATP for energy. The contraction cycle and Ca2+ transport back into the sarcoplasmic reticulum for relaxation require significant ATP. However, the ATP reserves in muscle fibers are limited and can only sustain contractions for a few seconds. Additional ATP production becomes necessary for prolonged contractions. As a result, muscle fibers generate ATP through various sources,...
Cross-bridge Cycle01:26

Cross-bridge Cycle

As muscle contracts, the overlap between the thin and thick filaments increases, decreasing the length of the sarcomere—the contractile unit of the muscle—using energy in the form of ATP. At the molecular level, this is a cyclic, multistep process that involves binding and hydrolysis of ATP, and movement of actin by myosin.
Actin and Myosin in Muscle Contraction01:16

Actin and Myosin in Muscle Contraction

Actin and myosin are contractile proteins that form the sarcomere found in skeletal muscle tissues for regulating muscle contraction. Actin, a globular contractile protein, interacts with myosin for muscle contraction. The skeletal tissue appears striped or striated under a microscope due to the repeated arrangement of contractile proteins actin and myosin along the length of myofibrils. Dark A bands and light I bands repeat along myofibrils, and the alignment of myofibrils in the cell causes...