Anatomy & Physiology Part 6: The Musculoskeletal System

An advanced quiz on the body's framework and engines of movement.

📖 Core Concepts Review

SystemComponentPrimary FunctionKey Concepts
🦴 Skeletal SystemBone & JointsSupport, protection, hematopoiesis, storageOsteoblasts, Osteoclasts, Red Marrow, Synovial Joints
💪 Muscular SystemSarcomereContractile unit of muscleActin (thin), Myosin (thick), Z-lines
⚙️ ContractionSliding Filament TheoryMolecular basis of muscle contractionCa²⁺, ATP, Troponin, Tropomyosin

Problem 1: The Role of Calcium

Medium
Muscle ContractionCalciumProteins

In the sliding filament model of muscle contraction, what is the direct role of calcium ions (Ca²⁺)?

A

To bind to myosin heads, causing them to detach from actin.

B

To bind to tropomyosin, moving it away from the actin binding sites.

C

To provide the energy for the myosin power stroke.

D

To bind to troponin, which then causes tropomyosin to shift and expose the myosin-binding sites on actin.