Which statement about striated skeletal muscle is true?   A. The tension generated by a muscle is invariable.   B. Mechanical summation of twitches in a muscle fiber leads to a graded increase in the tension that is above that generated by a single twitch.   C. A single action potential arriving at the neuromuscular junction is not sufficient to cause a muscle fiber to twitch.   D. Muscle twitches are able to mechanically sum when Ca2+ is quickly and completely removed from the sarcoplasm between action potentials.   E. An action potential in the muscle cell activates contraction by releasing Na+ into the sarcoplasm.

Q: What is the role of ATP in muscle function? a. ATP provides energy that enables myosin to form cross…

A: ATP stands for adenosine triphosphate. It is an energy coin of the cell. It is produced in the…

Q: The cross bridges of the sarcomere in skeletal muscle are made up of                 A. myelin.…

A: Introduction:-  Muscles are delicate tissue present in most animals . These contain filaments like…

Q: Predict what might happen to a muscle cell that is extensible but not elastic. What if the reverse…

A: Extensibility and elasticity are the properties of every muscle of the body.  Extensibility is…

Q: Select one or more: - a. No tension can be generated. b. Both contractile and elastic forces…

A: Stretching helps to keep our muscles flexible, strong, and healthy, and its very much needed for…

Q: The sliding filament mechanism describes the process during which: a. actin and myosin slide…

A: The muscles of the body serves main role in the movement of the body parts such as legs, arms and…

Q: The Sarcomere 2 Thin filaments are often named for which protein? a. actin b. myosin c. troponin d.…

A: The sarcomere is the smallest functional unit of a skeletal muscle fiber. It is a highly organized…

Q: Which arrangement best describes a bipennate muscle?a. The muscle fibers feed in on an angle to a…

A: A muscle can be defined as the soft tissue present in the body of most animals acting as a source of…

Q: The unit of muscle structure that is composed of bundles ofmyofibrils, enclosed within a sarcolemma,…

A: Muscle cells or muscles fibres forms the muscle tissue. The muscle tissue together forms a muscle…

Q: Calcium plays a crucial role in the contraction of skeletal muscles. i. Where is calcium stored…

A: The sliding filament theory was proposed as an explanation for muscle contraction. It is based on…

Q: This player in smooth muscle contraction is analogous to troponin in skeletal and cardiac muscle…

A: The muscular system is one of the major organ systems in the body. It contains three forms of…

Q: Which of the following statements about the Ca2+ release channels in the sarcoplasmic reticulum is…

A: The right answer is option b) They are one-tenth the size of the voltage-gated Ca 2+channels. The…

Q: Which item is biggest? A. myosin head B. myofibril C. troponin D. sarcomere

A: Muscles are compact structures made up of highly tensile , strong, long, multinucleated cells called…

Q: What role (function) does calcium have within a muscle fiber? a. trigger muscle potentials along…

A: Calcium is present in the sarcoplasmic reticulum until and unless it is released by the stimulus. It…

Q: What is the first and most direct energy source for muscle con￾traction? a. glucose b. ATP c.…

A: Answer- The muscle contraction is the crutial step in the movement and locomotion.

Q: When we increased the frequency, why could we see an in increase in the force of contraction? Is it…

A: An action potential can be defined as a rapid increase and decrease in the membrane potential of the…

Q: Within the first few seconds of a 5-minute race, stored ATP isdepleted. How do muscles obtain energy…

A: Respiration is the development of oxygen from the external climate to the cells inside tissues, and…

Q: Which is the first step in the contraction phase of the excitation-contraction coupling? a. Action…

A: Excitation-contraction coupling commences with depolarization and stretch of an AP along the…

Q: Which statement(s) about human neuromuscular innervation is/are true? A. A single spinal motor…

A: A chemical synapse between a motor neuron and a muscle fibre is known as a neuromuscular junction.…

Q: What event causes a troponin-tropomyosin complex to regain its original shape in muscle relaxation?…

A: Muscle contraction is the activation and formation of tension sites with muscle fibres, while muscle…

Q: Which characteristic or component is NOT shared by skeletal muscle and cardiac muscle? I. Electrical…

A: There are three types of muscles in the body. Smooth muscles and cardiac muscles are involuntary…

Q: The plasma membrane of a skeletal muscle fiber is called thea. sarcoplasmic reticulum.b.…

A: Skeletal muscles are involved in movement. Contraction of skeletal muscles makes movement possible.…

Q: Muscle fibers contractions differ with regard to tension and shortening. When a muscle Fiber begins…

A: Isometric and isoconcentric

Q: Calcium ions are responsible for unmasking of active site on which protein for cross bridge activity…

A: The muscle fibers contain sarcomeres that are the structural units responsible for muscle…

Q: In a skeletal muscle fiber, Ca2+ is released from a. ACh receptors. b. the motor end plate. c. the…

A: Skeletal muscle mainly attaches to the skeletal system via tendons to maintain posture and control…

Q: Which cell type helps to repair injured muscle fibers?a. ganglion cellsb. myotube cellsc. myoblast…

A: Muscle fibers, or muscle cells, are formed when the developmental myoblasts fuses together, this…

Q: What structure on a muscle fiber is composed of largely two varieties of contractile proteins--actin…

A: Muscle fibre is a single muscle cell. These muscles help control our bodily movement.

Q: Which of the following is the site of calcium ion storage within muscles? a. T tubules b.…

A: Muscles are the body tissues that are principally accountable for causing movement in the body.…

Q: if, in a laboratory, a skeletal muscle cell receives a single stimulus to contract, it produces a…

A: As per our honor code, we are authorized to answer only one question at a moment. So, we are…

Q: Which of the following is true concerning the role of Calcium in the contraction of muscle- cells?…

A: A muscle is a smooth tissue in animals. On the basis of structure, contractile properties and…

Q: What type of motor neuron stimulates skeletal muscle fibers to contract by the…

A: Electrochemical action in skeletal muscle fibers causes myofilament movement. Excitation-contraction…

Q: During which phase of the crossbridge cycle is ATP split into ADP and Pi? A. Immediately preceding…

A: Cross bridge cycling refers specifically to the action of the cross-bridge, that being the head and…

Q: During which phase of a twitch in a muscle fiber istension the greatest?a. resting phaseb.…

A: The phenomenon of lifting or moving an object (load) involves the sarcomeres present in the muscle…

Q: On a microscopic scale, explain how muscle fibers move in order to make a muscle shorter? Explain…

A: The cellular respiration provides energy (ATP) for the muscle contraction and The nervous system…

Q: What might happen if skeletal muscle lacked tropomyosin?   A. The striation pattern would…

A: Myogenesis is the process of formation of muscles from the mesodermal layer of embryonic germ cells.…

Q: Put the following in order to accurately follow the sequence of events associated with muscle fiber…

A: Relaxing of muscle filaments starts with the motor neuron, which stop delivering its compound sign,…

Q: Myosin binds to actin, then bends. What is ATP needed for next? A. to pump the Ca++ “keys” back into…

A: D option is the correct statement.

Q: What happens at a neuromuscular junction? a. An electrical impulse causes the release of a chemical.…

A: A neuromuscular junction is a chemical synapse between a motor neuron and a muscle fiber. It permits…

Muscle Action

A change in the body or a bodily organ as a result of its functioning is referred to as an action. Muscle action can be defined as the specific movement of a bodily part generated by the contraction of a muscle. The muscle proteins actin and myosin are the important contractile proteins involved in muscle action. Muscle contraction, in addition to movement, serves several other important functions in the body, including posture, heat generation, and joint stability. Muscle contraction maintains posture, which includes standing and sitting.