Chapter 7, Problem 2AYB

At the gym Sean gets on a stair-climbing machine and climbs as fast as he can for fifteen minutes. At the end of that time he is breathing hard and his quadriceps and other leg muscles are aching. What is the physiological explanation for these Symptoms?

Which element is important in directly Triggering contraction? sodium (Na+) calcium (Ca++) potassium (K+) chloride (Cl- )

After death, calcium pumps no longer function and the calcium ion concentration of muscle fiber cytoplasm increases. The result is rigor mortis a state or postmortem muscle contraction. Explain why this contraction occurs and why it ends only when myosin heads begin to break down.

Which of the following properties is not common to all three muscle tissues? excitability the need for ATP at rest, uses shielding proteins to cover actin binding sites elasticity

The release of calcium ions initiates muscle contractions. Watch this video (http://openstaxcollege.org/l/calciumrole) to learn more about the role of calcium. (a) What are “T-tubules� and what is their role? (b) Please also describe how actin-binding sites are made available for cross-bridging with myosin heads during contraction.

______ muscle pulls on bones and _______ muscle regulates the diameter of blood vessels. a. Skeletal / cardiac b. Smooth / cardiac c. Skeletal / smooth d. Smooth / skeletal

A motor unit is _________. a. a muscle and the bone it moves b. two muscles that work in opposition c. the amount a muscle shortens during contraction d. a motor neuron and the muscle fibers it controls

Which muscle type(s) (skeletal, smooth, or cardiac) can regenerate new muscle cells/fibers? Explain your answer.

Watch this animation (http://openstaxcollege.org/l/hipreplace) to observe hip replacement surgery (total hip arthroplasty), which can be used to alleviate the pain and loss of joint mobility associated with osteoarthritis of the hip joint. What is the most common cause of hip disability?