4 terms

Mechanism of Skeletal Muscle Contraction

Step 1
- A nerve impulse strikes a muscle fiber.
Step 2
- This causes calcium ions to flood the sarcomere.
- Calcium ions allow ATP to expend energy.
Step 3
- The myosin fibers creep along the actin, causing the muscle to contract.
Step 4
- Once the nerve impulse has passed, calcium is pumped out and the contraction ends.