Muscular System

When a muscle becomes shorter and causes movement it is said to have?

• atrophy

• contractibility

• extensibility

• elasticity

Answer explanation

When a muscle shortens and causes movement, it demonstrates contractibility. This ability to contract is essential for muscle function, distinguishing it from atrophy (wasting), extensibility (stretching), and elasticity (returning to shape).

A body builder's muscles enlarge after months of exercise, this is known as?

• hypertrophy

• hyperthyroid

• atrophy

• strain

Answer explanation

The enlargement of a body builder's muscles after exercise is called hypertrophy. This process involves an increase in the size of muscle fibers, which occurs as a result of consistent strength training.

What type of muscle can sustain contraction for long periods of time?

• Smooth

• skeletal

• cardiac

Answer explanation

Smooth muscle can sustain contractions for long periods without fatigue, making it ideal for functions like maintaining blood vessel tone. In contrast, skeletal muscle tires quickly, and cardiac muscle has a rhythmic contraction pattern.

What type of muscle is also known as voluntary?

• Smooth

• skeletal

• cardiac

• sphincter

Answer explanation

Skeletal muscle is known as voluntary muscle because it is under conscious control, allowing us to move our limbs. In contrast, smooth and cardiac muscles operate involuntarily.

Sitting or Standing up straight demonstrates what function of the muscular system?

• body heat

• movement

• posture

Answer explanation

Sitting or standing up straight is a clear demonstration of posture, which is a key function of the muscular system. It helps maintain body alignment and stability.

Stretching your muscles after exercise will give what outcome?

• atrophy

• contractibility

• extensibility

• hypertrophy

Answer explanation

Stretching your muscles after exercise improves their extensibility, allowing them to lengthen and become more flexible. This is beneficial for overall muscle function and injury prevention.

A patient's arm has been in a cast and the muscle is smaller from disuse, this is known as?

• hypertrophy

• muscle tone

• atrophy

• strain

Answer explanation

The correct answer is atrophy, which refers to the decrease in muscle size due to disuse, such as when an arm is in a cast. Hypertrophy is the opposite, muscle tone refers to muscle firmness, and strain involves injury.

Muscles are partially contracted at all times, this is known as?

• hypertrophy

• muscle tone

• atrophy

• strain

Answer explanation

Muscle tone refers to the continuous and passive partial contraction of the muscles, which helps maintain posture and readiness for action. This is why the correct answer is muscle tone.

Tags

NGSS.HS-LS1-3

Regular exercise and training will:

• decrease circulation

• reduce muscle efficiency

• cause muscle atrophy

• improve muscle tone.

Answer explanation

Regular exercise and training enhance muscle tone by increasing muscle strength and endurance, leading to better overall fitness. The other options incorrectly suggest negative effects of exercise.

When muscles relax and return to there original shape what characteristic of muscle is being demonstrated?

• elasticity

• irritability

• extensibility

• contractibility

Answer explanation

When muscles relax and return to their original shape, they demonstrate elasticity. This characteristic allows muscles to stretch and then return to their resting state, distinguishing it from other properties like irritability or contractibility.