22. Summarize the events that occur during the Contraction Phase in a skeletal muscle(recall the excitation-contraction coupling phase relays an action potential from a somaticmotor neuron to the sarcolemma of the skeletal muscle fiber).Practice by drawing in circled numbers in the images below to match the steps I havesummarized below.Contraction Phase:1. Ca²+ ions released from the cisternae bind to the protein troponin on the thin filament.2. This moves tropomyosin and uncovers the actin binding site = actin active site.3. The myosin head binds to actin. The myosin head is already energized and has ADP and aPO₁ attached.4. The phosphate group falls off the myosin head and the head PIVOTS and pulls the thinfilaments toward the M-line (POWER STROKE). The ADP falls off.5. To break the cross-bridge (DETACHMENT), ATP binds to the myosin.6. ATP is then hydrolyzed to ADP and a phosphate group (a PO.) and the energy releasedenergizes the myosin head for another round of binding (if Ca²* is still available in the cell) EContracting sarcomareactin tropomyosin troponin Ca*²Myosinhead in"cocked"positionMyosinheadHONADPActinactive siteThin filamentPortion ofthick filament(myosin)FountlandMyosin headIn relaxedpositionareADP

There are a few important points that should be kept in mind : In nerve and muscles cell, membrane…

motor neuron to the sarcolemma of the skeletal muscle fiber). Practice by drawing in circled numbers in the images below to match the steps I have summarized below. Contraction Phase: 1. Ca²+ ions released from the cisternae bind to the protein troponin on the thin filament. 2. This moves tropomyosin and uncovers the actin binding site = actin active site. 3. The myosin head binds to actin. The myosin head is already energized and has ADP and a PO4 attached. 4. The phosphate group falls off the myosin head and the head PIVOTS and pulls the thin filaments toward the M-line (POWER STROKE). The ADP falls off. 5. To break the cross-bridge (DETACHMENT), ATP binds to the myosin. 6. ATP is then hydrolyzed to ADP and a phosphate group (a PO) and the energy released energizes the myosin head for another round of binding (if Ca²+ is still available in the cell)

motor neuron to the sarcolemma of the skeletal muscle fiber). Practice by drawing in circled numbers in the images below to match the steps I have summarized below. Contraction Phase: 1. Ca²+ ions released from the cisternae bind to the protein troponin on the thin filament. 2. This moves tropomyosin and uncovers the actin binding site = actin active site. 3. The myosin head binds to actin. The myosin head is already energized and has ADP and a PO4 attached. 4. The phosphate group falls off the myosin head and the head PIVOTS and pulls the thin filaments toward the M-line (POWER STROKE). The ADP falls off. 5. To break the cross-bridge (DETACHMENT), ATP binds to the myosin. 6. ATP is then hydrolyzed to ADP and a phosphate group (a PO) and the energy released energizes the myosin head for another round of binding (if Ca²+ is still available in the cell)

Human Physiology: From Cells to Systems (MindTap Course List)

9th Edition

ISBN:9781285866932

Author:Lauralee Sherwood

Publisher:Lauralee Sherwood

Chapter8: Muscle Physiology

Section: Chapter Questions

Problem 12RE

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5. State the structure and function of each of the following parts of a muscle fiber. (See pg. 13 of Filled In BIOL 2401 Comp Obls.) Practice with this interactive online card activity. W Sarcolemma Sarcoplasm sarcoplasmic reticulum transverse tubules ish (United States) ● Definition Platelets that cross the cell which has a lots of acetylcholine receptors ● Platelets that cross the cell which has a lots of acetylcholine receptors 6. Identify each of the following structures when given images of skeletal muscle fibers such as the one below. an entire muscle fiber myofibril myofilaments SEP 9 Function Regulates what crosses the cells that has lots of acetylcholine receptors · (smooth ER) - stores Ca+2 ions sarcoplasmic reticulum transverse tubules . cisternae MacBook Air 0 Focus
Give an account of the excitation-contraction coupling (Figure 3) in skeletal muscle fibers. Highlight the role of dihydropyridine receptors and ryanodine receptors and the fate of A detailed description of the cross bridge cycle is not calcium ions after contraction. necessary. -Axon teminal of (=) somatic motor neuron ACh Muscle fiber potential Pion ++ Action potential- Na Motor end plate- T-tubule Sarcoptasmic reticulum lellll Ca2+ DHP receptor Tropomyosin Troponin z disk Actin M line Myosin head Myosin thick filament
17.For the hierarchy of skeletal muscle organization, which accurately lists the order of structures from "small" to "big"?(This is a multiple choice question choose the answer from the choices below) A.skeletal muscle; bundles of muscle fiber; myofibril; muscle fiber; sarcomere B.sarcomere; myofibril; muscle fiber; bundles of muscle fiber; skeletal muscle C.skeletal muscle; sarcomere; muscle fiber; myofibril D.None of the choices are correct.
96. An investigator is studying the contraction and relaxation of vascular smooth muscle in an experimental animal model. Which of the following describes the most likely order of events during this process? 0000000 200602 H) Myosin Light Chain Phosphorylation 1 2 2 3 3 4 4 Binding of Calcium to Calmodulin 3 1 4 2 4 2 3 Myosin Light Chain Dephosphorylation 2 3 4 3 4 2 1 2 Calcium Entry Into the Cell 4 2 3 1 1 1 3 1
(1) The reading for today (Lieber and Ward, 2011) and your textbook describe the length-tension relationship of muscle, which can be explained by the figure below. Describe physiologically what is happening to explain the length-tension relationship, as shown by this figure. (a) 120 maximum tension (%) 100 80 60- 40 20 0 1.0 1.5 2.0 active (3) passive 2.5 3.0 3.5 4.0 length (um)
Considering the Length-Tension Relationship of skeletal muscle fibers, over stretching a muscle fiber or not stretching a muscle fiber enough, results ina decrease in force developed (during contraction) because: 27. A. An "over-stretched" muscle fiber or an “under-stretched" muscle fiber will not allow Calcium, from the sarcoplasmic reticulum, to adequately diffuse into the cytoplasm. B. An "over-stretched" muscle fiber or an "under-stretched" muscle fiber will not allow an optimum amount of contact and overlap for the contractile proteins. C. An "over-stretched" muscle fiber or an“under-stretched" muscle fiber will not allow the Action Potential to reach the troponin-activation channels. D. An "over-stretched" muscle fiber or an "under-stretched" muscle fiber will not allow the Sodium current to depolarize the membrane. Teurons to
* The figure below is called the It shows the amount of tension generated by a muscle and the force of contraction depends on how stretched or contracted it was before it was stimulated. * 100 80 (d) 60 (e) Normal /range 40 (a) 20 1.2 μm 1.6 μm 2.1 μm 2.2 um 2.6μm 3.6 μη Decreased length Increased length Optimal resting length Tension (percent of maximum)
Now in your own words, EXPLAIN (1) howa neural impulse is transferred to a muscle cell this is the process of “muscle excitation"), and (2) how the electrical impulse travels into he T-tubules and causes calcium to be released from the sarcoplasmic retículum (this is the process of “excitation-contraction coupling"): OMADidoinos reticulum 5. se mo S1e hosph erah anism
First, explain how resting membrane potential is established in terms of ion concentration and electric charge. Next, explain the process of neural signal transmission from an alpha motor neuron to the muscle fiber. Do this by explaining how an AP is generated (ions and membrane proteins) at the neuron, how the signal is propagated, what happens at the axon terminal, what happens at the motor endplate, and explain all the molecular events that occur to cause muscle contraction.
Which of the following is true concerning the role of Calcium in the contraction of muscle- cells? 23. A. skeletal muscle cells require an extracellular inward-Calcium-current to stimulate the burst of Calcium from the sarcoplasmic reticulum. B. smooth muscle cells require an extracellular inward-Calcium-current to stimulate the burst of Calcium from the sarcoplasmic reticulum. C. cardiac muscle cells require an extracellular inward-Calcium-current to stimulate the An burst of Calcium from intracellular stored-Calcium-organelles. D. No type of muscle cell requires an extracellular inward-Calcium current for normal contractile-function.
34) what happens to skeletal muscle if there is no ATP present but plenty of calcium. Be specific relative to the sliding filament theory.
Describe what is happening overall in the first sentence. Then describe, in detail, what is happening in each step below. Include details about what is happening at steps 5 - 7 in terms of calcium and the contraction mechanism (from a different figure). (a) -Axon terminal of somatic motor neuron Muscle fiber ACh- potential Action Na+ Action potential- -Motor end plate- lell Ca2+ released Myosin thick filament 6 + + + ++