1. Key diagrams, animations and quizzes
Chapter 9 Muscles
Key diagrams, animations and quizzes

2. The sarcomere Contractile unit of a muscle
Contraction initiated when Ca+2 ions are released from sarcoplasmic reticulum by action potential in muscle sarcolemma
Ca+2 binds to troponin causing tropomysin to expose the binding sites of actin
Myosin heads bind with actin
Actin slides over surface of myosin when myosin heads flex.
ATP required
Distance between z-lines of sarcomere is reduced

3. Sarcomere contraction McGraw Hill with mini quiz
Breakdown of ATP and Cross-Bridge Movement During Muscle Contraction with mini Quiz
Myofilament Contraction with mini Quiz
Action Potentials and Muscle Contraction with mini Quiz

4. Muscle Contraction ( Flash animation)
Function of the Neuromuscular Junction (Quiz 1)
Animation: The Nerve Impulse: action potential and Quiz

6. +40
Na+/K+ pumps restore
Resting potential