Muscle Anatomy and Physiology Quiz

Describe the current concept of muscle contraction based on three (3) factors – neuro-electrical, chemical and energy sources;

• Muscle contraction is solely dependent on oxygen levels.
• Muscle contraction is driven by neuro-electrical signals, chemical interactions (calcium and ATP), and energy from ATP.
• Chemical signals are not involved in muscle contraction.
• Energy for muscle contraction comes exclusively from glucose.

Compare isotonic and isometric contractions;

• Isometric contractions are faster than isotonic contractions; isotonic contractions are slower.
• Isotonic contractions are only used in aerobic exercises; isometric contractions are used in strength training.
• Isotonic contractions occur without any change in muscle length; isometric contractions involve length changes.
• Isotonic contractions change muscle length; isometric contractions do not.

Discuss the importance of structure.

• Structure is irrelevant to understanding.
• Structure complicates information processing.
• Structure is important because it organizes information, enhances clarity, and improves understanding.
• Structure is only necessary for artistic works.

What are the three types of muscle?

• Skeletal

• Cardiac

• Smooth

What are the four characteristics associated with muscle tissue?

• Excitability

• Contractility

• Extensibility

• Elasticity

What is the 'all or none' principle?

• The 'all or none' principle states that a neuron either fires fully or not at all.
• The 'all or none' principle states that neurons can fire at varying intensities.
• The 'all or none' principle applies only to muscle contractions.
• The 'all or none' principle means a neuron can fire partially.

What happens during muscle contraction?

• Muscle fibers expand as myosin and actin slide apart, causing elongation.
• Muscle fibers lengthen as actin pulls on myosin, leading to relaxation.
• Muscle fibers shorten as myosin pulls on actin, leading to contraction.
• Muscle fibers remain unchanged during contraction, with no movement occurring.

What is the role of calcium in muscle contraction?

• Calcium is primarily responsible for energy production in muscles.
• Calcium ions inhibit muscle contraction by blocking actin and myosin interaction.
• Calcium ions facilitate muscle contraction by enabling the interaction between actin and myosin.
• Calcium plays no significant role in muscle contraction processes.

What causes the myosin heads to become energized?

• The presence of ADP + PO43- at the ATP binding site

• The release of calcium ions

• The binding of ATP to the myosin head

• The exposure of active sites on actin

What happens when a new molecule of ATP binds to the myosin head?

• The cross bridge detaches from the actin strand

• The myosin head pivots toward the center of the sarcomere

• The active sites on actin are exposed

• The myosin head becomes energized