CSCS: Structure & Function of Body System Flashcards

During the Valsalva maneuver, intra-abdominal pressure increases primarily to:

Answer: Stabilize the spine and trunk during maximal lifts

The Valsalva maneuver increases intra-abdominal and intrathoracic pressure, creating a rigid core that supports the spine against compressive forces during heavy lifts.

Which proprioceptor is located within the muscle belly and detects changes in muscle length?

Answer: Muscle spindle

Muscle spindles (intrafusal fibers) are length-sensitive mechanoreceptors embedded in the muscle belly that detect stretch and mediate the myotatic (stretch) reflex.

What percentage of cardiac output does the heart receive at rest?

Answer: 4–5%

The coronary circulation receives approximately 4–5% of total cardiac output at rest to supply the myocardium with oxygen and nutrients.

Which of the following bones is classified as a sesamoid bone?

Answer: Patella

The patella is the largest sesamoid bone in the body, embedded within the quadriceps tendon to improve mechanical advantage of the extensor mechanism.

The stretch-shortening cycle (SSC) is most closely associated with which type of muscle action sequence?

Answer: Eccentric followed by concentric

The SSC involves a rapid eccentric (lengthening) phase immediately followed by a concentric (shortening) phase, enhancing force production through elastic energy storage and neural potentiation.

Which blood vessel carries deoxygenated blood from the right ventricle to the lungs?

Answer: Pulmonary artery

The pulmonary artery (and its branches) carries deoxygenated blood from the right ventricle to the lungs for gas exchange — the only artery in the body that carries deoxygenated blood.

The quadriceps femoris group performs which primary joint action at the knee?

Answer: Knee extension

The four muscles of the quadriceps femoris (rectus femoris, vastus lateralis, vastus medialis, vastus intermedius) converge at the patellar tendon and extend the knee.