After you eat lunch, nerve cells in your stomach respond to the distension (the stimulus) resulting from the food. They relay this information to

Correct Answer: A

Rationale: Nerve cells (sensors) detect stomach distension and relay it to a control center (e.g., brainstem) in a feedback loop to process and respond (e.g., digestion adjustment). A set point is a target value, not a receiver. Effectors act (e.g., muscles), not receive. Sensors detect, not receive relayed data. Control center's role, per homeostasis, makes 'a' correct.

Correct Answer: A

Rationale: Muscle structure follows a hierarchy from largest to smallest: the whole muscle (e.g., biceps), encased by epimysium, contains fascicles bundles of fibers wrapped in perimysium. Each fascicle holds muscle fibers, single elongated cells in endomysium, visible under light microscopy. Within fibers, myofibrils, rod-like organelles, house sarcomeres, the contractile units. This sequence muscle (centimeters), fascicle (millimeters), fiber (micrometers), myofibril (nanometers) reflects anatomical nesting. Reversing fascicle and fiber misaligns bundles with cells, while placing myofibrils before fibers ignores their intracellular role. A whole muscle, spanning bone to bone, dwarfs fascicles (10-100 fibers), which outsize fibers (10-100 micrometers wide), containing hundreds of myofibrils. Dissection and electron microscopy confirm this descending scale, critical for understanding force transmission from sarcomeres to gross movement, distinguishing organizational levels in muscle physiology.

Correct Answer: C

Rationale: Muscles require regular movement to maintain their length and elasticity. Without stretching and contraction, they adapt to a shortened position due to immobility, losing their ability to elongate fully over time. This results in reduced elasticity, making them prone to stiffness and contractures. Longer and flexed muscles would imply active stretching, which doesn't occur without intervention. Fibrosis and spasticity suggest scarring or neurological overactivity, more common in specific conditions like cerebral palsy, not general immobility. Shorter and painful could occur, but pain isn't a universal outcome of disuse shortening and loss of elasticity are the primary physiological changes. This explanation underscores the need for exercise to preserve muscle function, aligning with the natural response of tissues to prolonged inactivity.

Correct Answer: C

Rationale: A CPM machine gently flexes and extends a joint post-surgery, like a knee replacement, to prevent stiffness and promote healing. The statement about resetting it to go faster and flex more suggests misunderstanding, as the machine's settings are calibrated by professionals to optimize recovery without overstraining the joint. Too much speed or flexion could damage tissues or delay healing. The other statements reflect humor, acceptance of rest periods, or comfort with the device, aligning with its use. Further teaching is needed to clarify that adjusting the CPM independently risks harm, emphasizing the importance of following prescribed parameters for safe, effective rehabilitation.

Correct Answer: B

Rationale: An abductor wedge keeps the legs apart post-hip replacement to prevent dislocation by maintaining proper alignment. Assessing peripheral circulation is critical, as pressure from the wedge could compress blood vessels or nerves, leading to numbness, swelling, or impaired flow, which needs prompt correction. Muscle spasms might occur but aren't the primary concern with the wedge's positioning. Compression fractures relate to spinal issues, not hip surgery. Wedge size matters for comfort but is secondary to circulation, which directly impacts tissue health. Monitoring circulation ensures the device supports recovery without causing vascular compromise, a key risk in this context.