Human Muscular System

What is the main function of the muscular system?

• Transport blood

• Produce movement

• Protect organs

• Digest food

Answer explanation

The main function of the muscular system is to produce movement. Muscles contract to enable motion of the body and its parts, making this the primary role of the muscular system, unlike the other options listed.

Which type of muscle is voluntary?

• Cardiac muscle

• Smooth muscle

• Skeletal muscle

• Visceral muscle

Answer explanation

Skeletal muscle is the only type of muscle that is under voluntary control, allowing us to consciously move our limbs. In contrast, cardiac and smooth muscles operate involuntarily.

Where is cardiac muscle found?

• Arms

• Stomach

• Heart

• Lungs

Answer explanation

Cardiac muscle is a specialized type of muscle found only in the heart. It is responsible for pumping blood throughout the body, distinguishing it from other muscle types found in the arms, stomach, and lungs.

What type of muscle lines the walls of internal organs like the stomach?

• Skeletal muscle

• Smooth muscle

• Cardiac muscle

• Striated muscle

Answer explanation

Smooth muscle lines the walls of internal organs like the stomach, allowing for involuntary movements such as digestion. Unlike skeletal muscle, which is under voluntary control, smooth muscle functions automatically.

Which of the following connects muscles to bones?

• Ligaments

• Cartilage

• Tendons

• Fascia

Answer explanation

Tendons are the connective tissues that attach muscles to bones, allowing for movement. Ligaments connect bones to other bones, cartilage provides cushioning, and fascia surrounds muscles.

What happens when a muscle contracts?

• It lengthens

• It shortens

• It breaks apart

• It becomes weaker

Answer explanation

When a muscle contracts, it shortens to generate force and movement. This is a fundamental property of muscle tissue, allowing it to pull on bones and create motion.

What is the primary energy molecule required for muscle contraction?

• ATP (adenosine triphosphate)

• Glucose

• Calcium

• Oxygen

Answer explanation

ATP (adenosine triphosphate) is the primary energy molecule required for muscle contraction. It provides the energy needed for the interaction between actin and myosin filaments during muscle contraction.

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Which muscle is responsible for breathing?

• Biceps brachii

• Diaphragm

• Trapezius

Answer explanation

The diaphragm is the primary muscle responsible for breathing. It contracts to create a vacuum that allows air to flow into the lungs, while the biceps brachii and trapezius are not involved in the breathing process.

What term describes the ability of a muscle to return to its original shape after contraction?

• Extensibility

• Elasticity

• Contractility

• Excitability

Answer explanation

The term that describes a muscle's ability to return to its original shape after contraction is 'elasticity'. This property allows muscles to stretch and then return to their resting state.

What happens in a condition like muscle atrophy?

• Muscle fibers enlarge due to excessive use.

• Muscles weaken and shrink due to lack of use.

• Muscle fibers tear and repair excessively.

• Muscles lose their elasticity permanently.

Answer explanation

In muscle atrophy, muscles weaken and shrink due to lack of use. This occurs when muscle fibers are not engaged regularly, leading to a decrease in size and strength.

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