Concept explainers
Order the following events of excitation and excitation-contraction coupling. Put 1 by the first event, 2 by the second, and so on.
_______The motor end plate generates an end-plate potential.
________ The action potential spreads along the T-tubules, SR
________Acetylcholine binds to receptors on the motor end plate, and ligand-gated ion channels open.
_______
______The action potential propagates through the sarcolemma and dives deeply into the cell along the T-tubules.
Want to see the full answer?
Check out a sample textbook solutionChapter 10 Solutions
Human Anatomy & Physiology (2nd Edition)
- Figure 38.37 Which of the following statements about muscle contraction is true? The power stroke occurs when ATP is hydrolyzed to ADP and phosphate. The power stroke occurs when ADP and phosphate dissociate from the myosin head. The power stroke occurs when ADP and phosphate dissociate from the actin active site. The power stroke occurs when Ca2+ binds the calcium head.arrow_forwardExplain why (a) calcium ions and (b) ACh are vital for muscle contraction.arrow_forwardSkeletal muscle contraction requires _________. a. calcium ions b. ATP c. arrival of a nerve impulse d. all of the abovearrow_forward
- Humming birds and rattlesnakes can contract and relax skeletal muscle very quickly, i.e. in 10-20 milliseconds. Which of the following steps must they have shortened to speed up contractions? more brief neuronal action potentials more brief skeletal muscle attion potentials shorter duration of calcium in the cytosol all of the abovearrow_forwardWhich of the following is a correct sequence (in chronological order of occurrence) within excitation-contraction coupling? a. Synpatic vesicles fuse with the pre-synaptic membrane, Neurotransmitter binds to receptors in the post-synaptic membrane, Neurotransmitter diffuses across the synaptic cleft b. Neurotransmitter binds to receptors in the post-synaptic membrane, Synpatic vesicles fuse with the pre-synaptic membrane, Neurotransmitter diffuses across the synaptic cleft c. Synpatic vesicles fuse with the pre-synaptic membrane, Neurotransmitter diffuses across the synaptic cleft, Neurotransmitter binds to receptors in the post-synaptic membranearrow_forwardHuman Anatomy and Physiology Describe in detail the events at the neuromuscular junction and how these events allow for the excitation-contraction coupling event to occur. Be sure to also include in detail all the steps at the NMJ and the steps of the excitation-contraction coupling event.arrow_forward
- In cardiac muscle, which ion serves both to depolarize the cells and as the essential link to myocyte contraction (the troponin/tropomyosin part)? a-Na+ b-Ca+ c-Ca2+ d-Cl-arrow_forwardIf a muscle cell’s sarcoplasmic reticulum had little to no Ca2+, could the muscle cell still produce an electrical impulse, and would the muscle cell still contract? Explain.arrow_forwardDetermine whether the following description is common to skeletal muscle, cardiac muscle or both skeletal and cardiac muscle. increase in tension during contraction of the muscle organ involves recruitment of other cells is primarily under the control of the autonomic nervous system all cells depolarize and contract during every contraction of the muscle organ different neurotransmitters can increase or decrease the rate of contraction action potentials begin electrical depolarization by a voltage-gated Na+ channel 1. skeletal muscle 2. cardiac muscle increase in cytosolic 3. skeletal muscle and cardiac muscle calcium increases tension in muscle cells prolonged depolarization is due to Ca2+ influx across the plasma membrane contraction is not under the control of hormones relaxation occurs when cytosolic calcium is reduced to resting levels increase in tension during contraction of single cells is associated with a higher frequency of action potentialsarrow_forward
- Explain what is meant by the term excitation-contraction coupling.arrow_forwardThe electrochemical gradient of a muscle cell at rest or its resting membrane potential is slightly negative inside the plasma membrane and slightly positive just outside the plasma membrane and has an ionic gradient of more potassium ions inside the cell and more sodium ions outside the cell. Therefore, a muscle cell at rest is said to be __________________ and has membrane potential. about to exocytose synaptic vesicles containing acetylcholine polarized experiencing an action potential about to allow an influx of potassium ions into the cell depolarizedarrow_forwardSkeletal muscle is described as striated. What are the lighter, thinner stripes noted under the microscope? Group of answer choices troponin actin myosin dystrophin Rather than innervating individual muscle fibers, motor neurons often innervate two or more muscle fibers. The motor neuron and the muscle fibers it innervates are together called a: Group of answer choices motor unit myofibril muscle fascicle motor fascia Fast glycolytic muscle fibers allow for relatively quick ATP energy production by splitting glucose (but eventually leads to fatigue), a process described as: Group of answer choices fermentation aerobic pathway anaerobic pathway ATP reserve usearrow_forward
- Biology 2eBiologyISBN:9781947172517Author:Matthew Douglas, Jung Choi, Mary Ann ClarkPublisher:OpenStaxHuman Physiology: From Cells to Systems (MindTap ...BiologyISBN:9781285866932Author:Lauralee SherwoodPublisher:Cengage LearningHuman Biology (MindTap Course List)BiologyISBN:9781305112100Author:Cecie Starr, Beverly McMillanPublisher:Cengage Learning