Muscle Contraction Mechanisms and Concepts

Mr. Furlong introduces muscle contraction concepts, including threshold stimulus, all-or-none response, and recruitment. He explains the Maya Graham, detailing its four phases: latent, contraction, relaxation, and recovery periods. Each phase is analyzed, highlighting the role of calcium and myosin in muscle contraction. Examples of Maya grams illustrate muscle behavior under different conditions, emphasizing the importance of recovery periods to prevent fatigue.

What is the minimum strength needed to initiate a muscle contraction called?

• Muscle recruitment

• Latent period

• Threshold stimulus

• All-or-none response

Which concept explains that a muscle fiber will either fully contract or not contract at all?

• Partial contraction

• Muscle recruitment

• Threshold stimulus

• All-or-none response

What happens during the latent period of muscle contraction?

• Calcium is reabsorbed

• Muscle fibers fully contract

• Nerve impulse reaches the muscle fiber

• Oxygen is resupplied

During which period does myosin pull on actin to cause muscle contraction?

• Contraction period

• Recovery period

• Relaxation period

• Latent period

What occurs during the relaxation period of muscle contraction?

• Oxygen debt is created

• Nerve impulse is sent

• Calcium is reabsorbed

• Myosin attaches to actin

What is the purpose of the recovery period in muscle contraction?

• To allow myosin to attach to actin

• To resupply oxygen to muscle cells

• To create an oxygen debt

• To release calcium from the sarcoplasmic reticulum

In a Maya gram, what does a consistent contraction pattern indicate?

• Increased lactic acid

• Consistent recovery period

• Lack of oxygen supply

• Muscle fatigue

What happens when the recovery period is not sufficient in a muscle contraction cycle?

• Oxygen debt builds up

• Muscle fibers fully contract

• Myosin detaches from actin

• Calcium is released

What is observed in a Maya gram when recruitment occurs?

• Muscle fibers do not contract

• Fewer muscle fibers are stimulated

• More muscle fibers are stimulated

• Calcium is not released

What eventually happens to a muscle when it is held in contraction for too long?

• It contracts partially

• It experiences fatigue

• It becomes stronger

• It releases more calcium