7.3 Structure & Function of the Muscular System

Which joint action involves increasing the angle between two bones?

• Flexion

• Extension

• Rotation

• Abduction

Answer explanation

Extension is the joint action that increases the angle between two bones, such as straightening the arm or leg. In contrast, flexion decreases the angle, while rotation and abduction involve different movements.

What is the relationship between agonist and antagonist muscles?

• They work together

• They oppose each other

• They are unrelated

• They are identical

Answer explanation

Agonist and antagonist muscles have opposing functions. When an agonist muscle contracts to produce movement, the antagonist muscle relaxes to allow that movement, highlighting their opposing roles in muscle action.

Which of the following is a characteristic of fast twitch muscle fibres?

• Slow contraction

• High endurance

• Quick fatigue

• Low power

Answer explanation

Fast twitch muscle fibers are designed for quick bursts of power but fatigue quickly due to their reliance on anaerobic metabolism. This makes 'quick fatigue' the correct characteristic, unlike slow contraction or high endurance.

Which document is associated with doc-4736?

• Topic 7 summary

• Key terms glossary

• Revision quiz

• Health analysis report

Answer explanation

The document associated with doc-4736 is the 'Revision quiz'. This choice is correct as it directly relates to the content of the document, while the other options do not.

What are the four main categories of bones?

• Long, short, flat, irregular

• Round, square, triangular, oval

• Hard, soft, flexible, rigid

• Thick, thin, wide, narrow

Answer explanation

The four main categories of bones are long, short, flat, and irregular. These classifications are based on the shape and structure of the bones, which play different roles in the skeletal system.

Which of the following is an example of a freely movable or synovial joint?

• Sutures in the skull

• Vertebral column

• Hip joint

• Cartilage disc

Answer explanation

The hip joint is a synovial joint, allowing for a wide range of movement. In contrast, sutures in the skull are immovable, the vertebral column has limited movement, and cartilage discs provide cushioning, not movement.

What is the primary function of ligaments?

• To connect muscle to bone

• To connect bone to bone

• To produce synovial fluid

• To cushion the joint

Answer explanation

The primary function of ligaments is to connect bone to bone, providing stability to joints. This distinguishes them from tendons, which connect muscle to bone.

What is the role of synovial fluid in joints?

• To connect bones

• To act as a lubricant

• To produce cartilage

• To restrict movement

Answer explanation

Synovial fluid acts as a lubricant in joints, reducing friction between the cartilage of moving bones. This lubrication is essential for smooth joint movement and overall joint health.

What is the function of tendons?

• To connect bone to bone

• To attach muscle to bone

• To produce synovial fluid

• To cushion the joint

Answer explanation

Tendons are connective tissues that attach muscle to bone, enabling movement. They play a crucial role in transmitting the force generated by muscles to bones, which is essential for locomotion and various physical activities.

What is the characteristic of ligaments that helps in joint stability?

• Elasticity

• Inelasticity

• Flexibility

• Rigidity

Answer explanation

Inelasticity is crucial for joint stability as it prevents excessive movement and maintains the integrity of the joint structure, ensuring that ligaments can support and stabilize the joint effectively.