Biology · General Awareness

Muscle Biology

798 Questions

Muscle biology covers the structures, functions, and contraction mechanisms of skeletal, cardiac, and smooth muscles. Test questions target filaments, stimuli, and specific muscle roles. A clear understanding helps secure marks in biology sections.

Skeletal muscle controlCardiac muscle propertiesMuscle contraction mechanismActin and myosin filamentsMuscle functions

Muscle Biology Questions

Multiple choice

Which of the following is incorrect, regarding skeletal muscle fibre?

  1. It is lined by sarcolemma

  2. It is syncitium

  3. Each fibre is made up of a number of myofibrils

  4. Each myofibril is multi-coloured

  5. Each muscle bundle contains a number of muscle fibres
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

It is the correct answer as this option is incorrect. Each myofibril has alternate dark and light bands. It is not multi-coloured.

Multiple choice

Which of the options is incorrect regarding skeleton muscles?

  1. They have striped appearance under microscope

  2. They are involved in change in body postures

  3. They are also known as striated, voluntary muscles

  4. They are found in the inner walls of hollow organs

  5. They are associated with skeletal components of the body
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

This is the correct answer, as this option is incorrect. Visceral muscles are located in the inner walls of hollow visceral organs of the body as are the alimentary canal, reproductive tract, etc.

Multiple choice

Which of the following is the strongest muscle in the human body?

  1. Jaw muscle

  2. Bicep

  3. Tricep

  4. Heart

  5. Stomach
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The heart (cardiac muscle) is considered the strongest because it contracts continuously without rest throughout a lifetime. While the masseter (jaw) muscle generates more force per contraction, it cannot sustain this output continuously like the heart.

Multiple choice

Match the following:

 
a. Cardiac muscles 1. They are found in the walls of alimentary canal and internal organs, ducts of glands and blood vessels.
b. Smooth muscles 2. They are found in the muscles of limbs, body wall, face, neck, tongue, pharynx and diaphragm.
c. Striated muscles 3. They are found in the walls of the heart.

  1. a - 3, b - 1, c - 2

  2. a - 3, b - 2, c - 1

  3. a - 1, b - 2, c - 3

  4. a - 1, b - 3, c - 2

  5. a - 2, b - 1, c - 3
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

This is the correct option. Cardiac muscles are found in the walls of the heart. Smooth muscles are found in the walls of alimentary canal and internal organs, ducts of glands and blood vessels. Striated muscles are found in the muscles of limbs, body wall, face, neck, tongue, pharynx and diaphragm.

Multiple choice

What is the connective tissue covering that encloses the muscle belly called?

  1. Fascicles

  2. Perimysium

  3. Endomysium

  4. Sarcolemma

  5. Epimysium
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Epimysium is a layer of connective tissue which ensheaths the entire muscle. It is composed of dense irregular connective tissue. It is continuous with fascia and other connective tissue wrappings of muscle including the endomysium and perimysium. It is also continuous with tendons where it becomes thicker and collagenous. The epimysium also protects muscles from friction against other muscles and bones.

Multiple choice

Consider the following statements:

  1. Muscular tissue covers the outer surface of the whole body.
  2. Cardiac muscles present in the heart are of involuntary nature.

Which of the given statements is/are correct?

  1. Only 1

  2. Only 2

  3. Both 1 and 2

  4. Neither 1 nor 2
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Statement 1 is incorrect. Epithelial tissue covers the outer surface of the whole body. It also lines the internal organs, cavities and other parts of the body. Statement 2 is correct. Cardiac muscles are specialised involuntary muscles present in the heart. They help the heart to pump blood day and night.

Multiple choice

Which of the following statements does not characterise skeletal muscles in humans?

  1. It has the similar structure as that of cardiac muscle.

  2. Skeletal muscle cells contain myosin filaments.

  3. Skeletal muscle has a system of T-tubules.

  4. The myofibrils of skeletal muscle are enveloped by sarcoplasmic reticulum.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Skeletal muscle cells do not contain myosin filaments. Smooth muscle cells have no repeating sarcomeres, but a loose array of actin and myosin filaments.

Multiple choice

Which of the following does not characterise skeletal muscle contractions in humans?

  1. The alpha motor neuron generates action potential.

  2. The neurotransmitter noradrenaline diffuses across the synapse and binds to nicotinic acetylcholine receptors on the myocyte.

  3. The end-plate potential spreads evenly across the myocyte's sarcolemma.

  4. The T-tubule system accomodates voltage-dependent calcium plexus.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

This statement is incorrect. The neurotransmitter acetylcholine diffuses across the synapse and binds to nicotinic acetylcholine receptors on the myocyte, opening them. An influx of Na+ and an efflux of K+ results, depolarising the cell and generating an end-plate potential.

Multiple choice

In cardiac muscle, the excitation contraction coupling method is dependent on an anomaly famed as calcium-induced calcium release. Which of the following statements is true regarding excitation contraction coupling in cardiac muscles?

  1. Intracellular Ca+2 is drawn by endoplasmic reticulum ATPase pump.

  2. The cytoplasmic calcium binds to troponin T.

  3. The ryanodine receptors find out the increase in intracellular calcium ions.

  4. The action potential propogates across the T-tubules.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

This statement is incorrect as cytoplasmic calcium binds to troponin C instead of troponin T making the troponin complex to move off the actin binding site allowing the myosin head to bind to the actin filament.

Multiple choice

Which of the following statements concerning the role of Ca2+ in contraction of skeletal muscles is true?

  1. The SER acts as a reserve of Ca2+ for the contractile process.

  2. Ca2+ entry across the plasma membrane is significant in maintaing the contraction of skeletal muscle in the body.

  3. A rise in intracellular Ca2+ permits actin to interact with myosin.

  4. The tension of a skeletal muscle fibre is totally governed by G proteins.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The calcium for skeletal muscle contraction is derived from sarcoplasmic reticulum. The increase in intracellular calcium permits the interaction between actin and myosin head groups.