Explain how the following agents are involved in the excitation and contraction of skeletal muscle. i....

Explain how the following agents are involved in the excitation and contraction of skeletal muscle.

i. Acetylcholine (ACh)

ii. Calcium (Ca²⁺)

iii. Adenosine triphosphate (ATP)

Expert Solution

Mechanism of muscle contraction:

•>Muscle contraction is initiated by a signal sent by the CNS via a motor neuron.The junction between a motor neurons and the sarcolemma of the muscle fibre is called the Neuromuscular junction.

•A neural signal reaching this junction releases a neurotransmitter(Acetylcholine) which generates an action potential in the sarcolemma.This spreads through the muscle fibre and causes the release of calcium ions into the sarcoplasm.Increase in Ca++ level leads to the binding of calcium with the Troponin C subunit on actin filaments and thereby remove the masking of active sites for myosin.

•Utilising the energy from the hydrolysis of ATP, the myosin head now binds to the exposed active sites on actin to form a cross bridge.

•This pulls the attached actin filaments towards towards the centre of 'A' band.The 'Z' line attached to these actins are also pulled inwards thereby causing shortening of the sarcomere, i.e., contraction.

•The myosin,releasing the ADP and Pi goes back to its relaxed state.A new ATP binds and the cross- bridge is broken.The ATP is again hydrolysed by the myosin head and the cycle of cross bridge formation and breakage is repeated.

Sydney Mullin answered 1 year ago

During the excitation phase of the skeletal muscle cell contraction, the following occurs: 1) the muscle...

During the excitation phase of the skeletal muscle cell contraction, the following occurs: 1) the muscle fiber develops tension and shortens 2) the muscle fiber relaxes and returns to its original length 3) nerve action potentials lead to muscle action potentials A growing long bone in a child has only two types of cartilage at the epiphysis. These two areas are 1) elastic cartilage and epiphyseal plate 2) epiphyseal plate and epiphyseal line 3) primary and secondary ossification centers 4)...

Topic 6: Skeletal muscle contraction Describe in detail the entire process of excitation coupling in skeletal...

Topic 6: Skeletal muscle contraction Describe in detail the entire process of excitation coupling in skeletal muscle, begin with an action potential reaching the synaptic knob of a motor neuron through completion of a cross Bridge cycle. after detailing those events to include the following information Define a motor unit describe motor unit recruitment and Explain how these terms relate to excitation-contraction coupling. Define and describe muscle twitch and summation and explain how these terms relate to motor unit/motor unit...

Skeletal A) In skeletal muscle what do we mean by excitation-contraction coupling? B) What causes the...

Skeletal A) In skeletal muscle what do we mean by excitation-contraction coupling? B) What causes the excitation? Be specific as to the events and ions and channels involved. C) How is it linked to the contraction events? What ion is involved and how does it work to initiate contraction? (include the proteins activated) D) What causes relaxation? (you do not have to describe the complete contraction event, just what allows it to start and what ends it)

Describe the process of excitation-contraction coupling in a skeletal muscle fiber, starting at the very beginning...

Describe the process of excitation-contraction coupling in a skeletal muscle fiber, starting at the very beginning and working your way to the end of the process. Make sure you discuss all relevant steps in the correct order.

Compare and contrast cardiac and skeletal muscle in the following: Cellular structure Excitation-Contraction Coupling Action potential...

Compare and contrast cardiac and skeletal muscle in the following: Cellular structure Excitation-Contraction Coupling Action potential of Skeletal Muscle cells and Cardiac Contractile muscle cells Production of ATP Role of Calcium Mechanisms for increased strength/force of contraction

Compare and contrast the excitation-contraction coupling mechanisms of skeletal muscle versus contractile cardiac muscle. Need detailed...

Compare and contrast the excitation-contraction coupling mechanisms of skeletal muscle versus contractile cardiac muscle. Need detailed answers please.

Briefly describe the steps involved in the initiation of a contraction in a skeletal muscle fibre....

Briefly describe the steps involved in the initiation of a contraction in a skeletal muscle fibre. List the steps in the order that they occur. Start with an action potential on the sarcolemma and end with a description about how cross-bridges form. Include details about the intracellular structures and ion/s involved. You should provide 8 pieces of relevant information to obtain 8 marks.

Compare and contrast cardiac and skeletal muscle in terms of electrical stimulus and action potentials (excitation-contraction...

Compare and contrast cardiac and skeletal muscle in terms of electrical stimulus and action potentials (excitation-contraction coupling), role of calcium, energy use and production, and ways to develop increased force of contraction. How does the vulnerability of the myocardium relate to the fact that heart disease is the leading cause of death?

1. How is the contraction of a skeletal muscle cell different than the contraction of a...

1. How is the contraction of a skeletal muscle cell different than the contraction of a smooth muscle cell? How does this aid in each muscle cell's function? 2. What is the purpose of myoglobin in slow-twitch muscle fibers? Why is there more myoglobin in slow-twitch muscle fibers than in fast-twitch fibers? 3. What is the purpose of gap junctions in cardiac muscle cells and some smooth muscle cells?

1. How is the contraction of a skeletal muscle cell different than the contraction of a...

1. How is the contraction of a skeletal muscle cell different than the contraction of a smooth muscle cell? How does this aid in each muscle cell's function? 2. What is the purpose of myoglobin in slow-twitch muscle fibers? Why is there more myoglobin in slow-twitch muscle fibers than in fast-twitch fibers? 3. What is the purpose of gap junctions in cardiac muscle cells and some smooth muscle cells?

Question

Explain how the following agents are involved in the excitation and contraction of skeletal muscle. i....

Solutions

Expert Solution

Related Solutions

During the excitation phase of the skeletal muscle cell contraction, the following occurs: 1) the muscle...

Topic 6: Skeletal muscle contraction Describe in detail the entire process of excitation coupling in skeletal...

Skeletal A) In skeletal muscle what do we mean by excitation-contraction coupling? B) What causes the...

Describe the process of excitation-contraction coupling in a skeletal muscle fiber, starting at the very beginning...

Compare and contrast cardiac and skeletal muscle in the following: Cellular structure Excitation-Contraction Coupling Action potential...

Compare and contrast the excitation-contraction coupling mechanisms of skeletal muscle versus contractile cardiac muscle. Need detailed...

Briefly describe the steps involved in the initiation of a contraction in a skeletal muscle fibre....

Compare and contrast cardiac and skeletal muscle in terms of electrical stimulus and action potentials (excitation-contraction...

1. How is the contraction of a skeletal muscle cell different than the contraction of a...

1. How is the contraction of a skeletal muscle cell different than the contraction of a...