MEDizzy - A 62-year-old male presents with a hypokinetic movement

Feed Library Learning Discuss Leaderboard Journal

Musculoskeletal Physiology

A 62-year-old male presents with a hypokinetic movement disorder characterized by bradykinesia (paucity and slowness of movement). During a normal voluntary movement, which of the following occurs?

ExplanationIn general, small, weak, slow, fatigue-resistant muscle fibers are innervated by small spinal motoneurons, whereas, large spinal motoneurons innervate large, fast, strong, easily fatigable muscle fibers. During most normal reflex or voluntary movements, small spinal motoneurons are recruited before large motoneurons. The slow fatigue-resistant muscle fibers have a dense capillary network for perfusion and use mitochondrial oxidative metabolism to produce adenosine triphosphate (ATP).