Mock L2

Which of the following statements about synovial joints is true?

• The hip is an example of a saddle joint

• The elbow is an example of gliding joint

• The knee is an example of a hinge joint

• The shoulder is an example of a pivot joint

Answer explanation

The knee is indeed a hinge joint, allowing movement primarily in one plane (flexion and extension). The other statements incorrectly classify the hip, elbow, and shoulder joints.

Which of the following statements about the nervous system is true?

• Blood pressure is controlled by the somatic system

• Blood pressure is controlled by the autonomic system

• Skeletal muscle contraction is controlled by the parasympathetic nervous system

• Skeletal muscle contraction is controlled by the sympathetic nervous system

Answer explanation

Blood pressure is regulated by the autonomic nervous system, which controls involuntary functions. The somatic system manages voluntary movements, while the sympathetic and parasympathetic systems influence different aspects of autonomic control.

Which of the following describes the 'all-or-none' law?

• An action potential will maximally innervate a percentage of muscle fibres within a single motor unit

• An action potential will maximally innervate all muscle fibres within every motor unit

• An action potential will maximally innervate all muscle fibres within a single motor unit

• An action potential will maximally innervate a percentage of muscle fibres within every motor unit

Answer explanation

The 'all-or-none' law states that an action potential will maximally innervate all muscle fibres within a single motor unit, meaning that once the threshold is reached, all fibres in that unit are activated.

Which of the following describes a function of skeletal muscle?

• They relax and lengthen to perform a role as a fixator

• They relax and lengthen to perform a role as a synergist

• They contract and shorten to perform a role as a prime mover

• They contract and shorten to perform a role as an antagonist

Answer explanation

Skeletal muscles contract and shorten to create movement, acting as prime movers in various actions. This is essential for initiating and controlling movement, distinguishing it from other roles like fixators or antagonists.

Which of the following correctly describes the structure of synovial joints?

• Tendons attach bone to bone

• The synovial membrane prevents friction during movement

• The articular cartilage provides stability to the joint

• Ligaments provide stability to the joint

Answer explanation

Ligaments are key structures in synovial joints that connect bones to each other, providing stability. The other options incorrectly describe the roles of tendons, the synovial membrane, and articular cartilage.

Which of the following correctly describes the process of diffusion in the lungs?

• Diffusion is the movement of molecules from an area of lesser concentration to an area of higher concentration

• Diffusion involves the movement of oxygen into the capillaries to be expelled by the lungs

• Diffusion involves the movement of carbon dioxide into the capillaries to be used by the body

• Diffusion is the movement of molecules from an area of greater concentration to an area of lesser concentration

Answer explanation

Diffusion is the movement of molecules from an area of greater concentration to an area of lesser concentration. In the lungs, oxygen moves from the alveoli (high concentration) into the capillaries (low concentration).

Which of the following describes a function of the skeleton?

• The flat bones act as a levers for movement

• The irregular bones act as strong attachment points for muscles

• The long bones act as a levers for movement

• The short bones act as strong attachment points for muscles

Answer explanation

The irregular bones, such as the vertebrae, provide strong attachment points for muscles, supporting movement and stability. This distinguishes them from flat and long bones, which primarily serve as levers.

Which of the following describes how blood moves through the four chambers of the heart?

• Oxygenated blood from the left atria moves to the right ventricle

• Deoxygenated blood from the left atria moves to the right ventricle

• Oxygenated blood from the left atria moves to the left ventricle

• Deoxygenated blood from the left atria moves to the left ventricle

Answer explanation

Oxygenated blood from the lungs enters the left atrium, then moves to the left ventricle, which pumps it to the body. The other options incorrectly describe the flow of blood through the heart's chambers.

Which of the following describes the action of the gastrocnemius when it contracts eccentrically?

• The muscle shortens and the ankle plantar flexes

• The muscle lengthens and the ankle plantar flexes

• The muscle lengthens and the ankle dorsi flexes

• The muscle shortens and the ankle dorsi flexes

Answer explanation

When the gastrocnemius contracts eccentrically, it lengthens while controlling the movement of the ankle. This results in ankle dorsiflexion, as the muscle resists the force of the movement.

Which of the following sections of the spine has the least range of motion?

• Lumbar

• Thoracic

• Sacral

• Cervical

Answer explanation

The thoracic spine has the least range of motion due to its attachment to the rib cage, which stabilizes it and limits flexibility. In contrast, the cervical and lumbar regions allow for greater movement.