Search results
Although the term excitation-contraction coupling confuses or scares some students, it comes down to this: for a skeletal muscle fiber to contract, its membrane must first be “excited”—in other words, it must be stimulated to fire an action potential. The muscle fiber action potential, which sweeps along the sarcolemma as a wave, is “coupled” to the actual contraction through the ...
- 15.5: Physical Exercise
Anaerobic exercise is any physical activity in which muscles...
- Nervous System
This chapter describes neurons and other cells of the...
- 15.5: Physical Exercise
Dec 7, 2023 · For example, it would be utilised by the muscles of a 100m sprinter as sprinting involves an intense level of muscle contraction For prolonged activity, once the supply of phosphocreatine has been used up then the rate of muscle contraction must equal the rate of ATP production from both aerobic and anaerobic respiration
- Crossbridge Cycling
- Energy For Muscle Contraction
- Attributions
- References
Crossbridge cycling is a sequence of molecular events that underlies the sliding filament theory. There are many projections from the thick myosin filaments, each of which consists of two myosin heads (you can see the projections and heads in Figures 12.4.3 and 12.4.4). Each myosin head has binding sites for ATP (or the products of ATP hydrolysis: ...
According to the sliding filament theory, ATPis needed to provide the energy for a muscle contraction. Where does this ATP come from? Actually, there are multiple potential sources, as illustrated in Figure 12.4.5 below. 1. As you can see from the first diagram, some ATP is already available in a resting muscle. As a muscle contraction starts, this...
Figure 12.4.1 Armwrestling_Championships by Jnadler1 on Wikimedia Commons is used under a CC BY-SA 3.0(https://creativecommons.org/licenses/by-sa/3.0) license. Figure 12.4.2 Motor_End_Plate_and_Innervation by OpenStax on Wikimedia Commons is used under a CC BY 4.0(https://creativecommons.org/licenses/by 4.0) license. Figure 12.4.3 Sliding_Filament_...
3DBiology. (2017). Muscle contraction 3D. YouTube. https://www.youtube.com/watch?v=GrHsiHazpsw Betts, J. G., Young, K.A., Wise, J.A., Johnson, E., Poe, B., Kruse, D.H., Korol, O., Johnson, J.E., Womble, M., DeSaix, P. (2016, May 27). Figure 10.6Motor end-plate and innervation [digital image]. In Anatomy and Physiology(Section 10.2). OpenStax. https...
- Christine Miller
- 2020
Aug 3, 2023 · Isometric Contraction; In this type of contraction, there is change in muscle tension without change in muscle length. For instance, during grabbing something, muscles in forearm experience increase in tension, but there is no change in length of muscle of the forearm. Isotonic Contraction
This is the phase during which excitation and contraction are being coupled but contraction has yet to occur. The contraction phase occurs as the muscle generates increasing levels of tension; the Ca 2+ ions in the sarcoplasm have bound to troponin, tropomyosin has shifted away from actin-binding sites, cross-bridges have formed, and sarcomeres are actively shortening.
This page titled 13.1: Muscle Contraction is shared under a CK-12 license and was authored, remixed, and/or curated by CK-12 Foundation via source content that was edited to the style and standards of the LibreTexts platform.
Jun 24, 2021 · Contraction (Science: physiology) a shortening or reduction in size, in connection with muscles contraction implies shortening and/or development of tension. Origin: L. Contractus = drawn together
