ATI RN
Questions for Muscular System Questions
Question 1 of 5
Which of the following muscle structures is the largest?
Correct Answer: B
Rationale: A fascicle, a bundle of muscle fibres (cells), is larger than a single fibre, which contains myofibrils bundles of sarcomeres. Sarcomeres, the smallest contractile units, are within myofibrils. Fascicles, wrapped in perimysium, contribute to whole-muscle structure, distinguishing them as the largest listed unit, key to muscle organization and force production.
Question 2 of 5
Which of the following muscles increases the angle between the bones of the fingers and hand?
Correct Answer: A
Rationale: Increasing the angle between finger and hand bones means finger extension straightening from a flexed position. Extensor digitorum, on the forearm's dorsal side, contracts to pull finger phalanges, extending them at metacarpophalangeal joints. Extensor carpi ulnaris extends the wrist, flexor digitorum profundus flexes fingers, and abductor pollicis longus moves the thumb. Extensor digitorum's specific finger-extension role distinguishes it, essential for opening the hand, contrasting with wrist or thumb actions.
Question 3 of 5
Which list is in the correct order of DECREASING size?
Correct Answer: B
Rationale: Size hierarchy: muscle (organ) contains fasciculi (fibre bundles), then muscle fibres (cells), then myofibrils (fibre-length). Sarcomeres (2 micrometres) and myofilaments are within myofibrils, myosin is molecular. Only 'muscle, fasciculus, fibre, myofibril' descends correctly, distinguishing organizational scale, key to muscle structure understanding.
Question 4 of 5
Patients confined to bed and those with plaster casts immobilising a bone fracture suffer muscle wasting. What is the term used for this condition?
Correct Answer: A
Rationale: Disuse atrophy muscle shrinkage from inactivity occurs with immobilization, reducing stimulation despite intact nerves. Denervation atrophy follows nerve loss, dystrophy is genetic degeneration, and hypertrophy is growth. Disuse atrophy's link to lack of use distinguishes it, key to rehabilitation contexts.
Question 5 of 5
What does aerobic respiration refer to?
Correct Answer: B
Rationale: Aerobic respiration is oxidative phosphorylation in mitochondria, using oxygen to generate ATP from pyruvate, yielding high energy for sustained effort. Glycolysis is anaerobic or preparatory, gluconeogenesis synthesizes glucose. This oxygen-dependent process distinguishes it, key to endurance muscle energy, contrasting with anaerobic pathways.