Question

In: Anatomy and Physiology

Which of the following occurs during a muscle contraction ? The distance between the z-discs lengthens...

Which of the following occurs during a muscle contraction ?

		The distance between the z-discs lengthens
		The A band shortens
		The I band and the A band switch positions
		thick and thin myofillaments shorten
		The sarcomeres shorten

Jogging, swimming, and aerobics all have this effect on skeletal muscle tissue.

		Decreased # of myofillaments
		Increased # of nuclei per muscle cell
		Increased # of motor units
		None of the above
		Increased # of muscle fibers

In the sliding filament model, ________ stay in place and ________ are pulled toward the center of the
sarcomere.

		Z bands, A bands
		thin filaments, thick filaments
		muscle cells, myofibrils
		fast fibers, slow fibers
		myosin filaments, actin filaments

Expert Solution

1)CORRECT ANSWER IS OPTION E - SARCOMERE SHORTEN

Sarcomere are the basic functional unit of muscle.

Sarcomere are mainly composed of Actin filament and myosin filament . They are the main protein that help in teh muscle contraction.

Sarcomere is teh art present between 2 Zline ., it is composed of a myosin filament and 2 half of actin filament.

when the muscle contract the z line will come closer (sarcomere shorten) aand the central H zone ( Region of the A band where the actin filament are absent) will disappear.

A Band is the anisotropic band which contain both the Myosin filament and actin filament

I band or isothropic band is the region where the actin filament only present no myosin filaments.

2) OPTION E - Increased # of muscle fibers

Jogging , swimming running are the example for the aerobic exercise.

In aerobic exercise the glucose in teh muscle are completly oxidised aerobically into energy.

This help in the increase of muscle mass.

,Muscle mass is increase by the hypertrophy of the muscle to the stimuli.

Muscle fibers forming the muscle are increased in the number making the muscle bulker.

3)OPTION E - myosin filaments, actin filaments

Sliding filament theory explain the muscle contraction in the skeletal muscle.

when a motor nerve innervate the the muscle fibre , it releases acetylcholine neurotransmitter into the synapse -------> it bind with the postsynaptic receptor on the muscle membrane -------> depolarises the muscle membrane ------->Calcium ionare released by the sarcoplasmic reticulum ------> it bind with the Troponin c present on the tropomyosin - actin complex------> change in spatial configuration of the tropomyosin result in the exposure of actin binding site -------> Myosin filament bind with the exposed actin binding site ----> Actin filament slide over the myosin filament ----> muscle contract.

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)...

1) Write in order the sequence of events that occurs during muscle contraction. Begin in the...

1) Write in order the sequence of events that occurs during muscle contraction. Begin in the brain and include all action in the muscle. You can write it out like a flow chart, one action followed by the next. 2.The function of the T tubules is to _________. A) Store Ca2+ inside the muscle fiber. B) Rapidly conduct action potentials to the interior of the muscle fiber. C) To store neurotransmitter D) Conduct ATP molecules out of the mitochondria throughout...

Angular work is positive during eccentric muscle contraction and negative during concentric muscle contraction. With the...

Angular work is positive during eccentric muscle contraction and negative during concentric muscle contraction. With the aid of sketches, explain the reason for work to be positive and negative for eccentric and concentric muscle actions, respectively.

Which of the following are ways in which a graded response is achieved in a muscle contraction?

Which of the following are ways in which a graded response is achieved in a muscle contraction?Increase the number of motor neurons that communicate with each muscle cell.Varying the intensity of the action potential.Increase or decrease the rate of nervous stimulation to the muscle cells.Varying the number of muscle cells/fibers that contract.

Which off the following does NOT occur during skeletal muscle contraction? Titin fibers compress Actin and...

Which off the following does NOT occur during skeletal muscle contraction? Titin fibers compress Actin and myosin shorten Sarcomers shorten 2. Action potential propagated along the sarcolemma stimulate ___________ located on transverse tubules.2. Nicotinic receptors Ryanodine receptors DHP receptors 3. Which of the following does not occur during the "Excitation" of a skeletal muscle? Group of answer choices The cell membrane depolarizes ATPase on myosin heads split ATP The myosin head binding site on actin is exposed The passive force...

Which of the following involves a skeletal muscle (whole muscle)? Treppe Multiple wave summation Isotonic contraction...

Which of the following involves a skeletal muscle (whole muscle)? Treppe Multiple wave summation Isotonic contraction Consider the following events and choose the one that occurs last Na+ ions diffuse into the skeletal muscle cells ACH binds to receptor sites on Na+ ion channels Membrane permeability to Na+ ions increased The sphere of hydration is greater for Na+ H+ He+ H2O Which ectodermal cells use socium, Na+, as a component of depolarization? Heart muscle Smooth muscle Integument Motor neurons

During static muscle activity, there is a strong compressive effect from skeletal muscle contraction coupled with...

During static muscle activity, there is a strong compressive effect from skeletal muscle contraction coupled with an absence of rhythmic muscle activity. Describe how this would change arterial pressure (afterload) and venous return (preload) compared with dynamic activity.

Explain the process of contraction of: Skeletal muscle and cardiac muscle (show the differences between them)...

Explain the process of contraction of: Skeletal muscle and cardiac muscle (show the differences between them) Smooth muscle Draw the action potential of a skeletal muscle cell, Sinoatrial Node cell, cardiac muscle, and smooth muscle cell and explain the differences between them.

Which step of muscle contraction requires the presence of ATP?

9. Which of the following statements is true for an eccentric muscular contraction. The muscle lengthens....

9. Which of the following statements is true for an eccentric muscular contraction. The muscle lengthens. The maximum possible tension generated by a muscle at a given joint position is smaller during an eccentric contraction when compared to an isometric contraction. Shortening of m. triceps during elbow extension is an example of an eccentric contraction. Requires an external force acting on the bone to which the muscle is attached.