BM1004 PASS Wk8 (2023)

PASS Wk8

​Recap

• Skeletal muscle contraction

• Muscle metabolism

• Comparison of muscle types

Multiple Choice

What is the function of tropomyosin?

• To block myosin binding sites on actin

• To block actin binding sites on myosin

• To bind Ca2+ ions to induce a change in the structure of troponin

• To bind Ca2+ ions to induce a change in the structure of myosin

Multiple Choice

Which of the following changes is Incorrect for sarcomeres during contraction.

• The length between Z-disks changes

• The length of the H-zone decreases

• The length of the I-band decreases

• The length of the A-band increases

Multiple Choice

Which of these stores of energy last the least amount of time?

• Creatinine phosphate

• Anaerobic glycolysis

• Aerobic respiration

• The mitochondria is the powerhouse of the cell

Multiple Choice

How does a skeletal muscle increase the force it wants to exert?

• Muscle fibers contract faster and deeper

• Recruitment of more motor units

• Recruitment of smooth muscle cells

• Muscle fibers switch to a fast-glycolytic pathway

Multiple Choice

The muscle contraction shown at the front is an example of what type of contraction?

• Isotonic

• Isometric

Multiple Select

The 'slow' or 'fast' seen in muscle fiber types refers to what?

• The speed that the myosin heads contract at

• The rate at which the muscle fiber fatigues

• The energy source being used

• The metabolic pathway being used

Multiple Choice

Which of the following is Incorrect about motor units in skeletal muscle?

• One neuron activates ALL the fibers in the motor unit

• ALL the fibers in the motor unit are of the same muscle type (e.g. slow oxidative)

• Motor units form the basic unit of contraction in skeletal muscles

• If one fiber in a muscle unit contracts, the rest will contract

Multiple Choice

Cardiac muscle has a sustained plateau in its action potentials due to the influx of what ion?

• Ca2+

• Mg2+

• Fe2+

• Fe3+

Multiple Choice

Which of the following muscle types is NOT striated (revision)?

• Skeletal

• Smooth

• Cardiac

Multiple Choice

Which of the following muscle types do NOT have a centrally located nucleus (revision)?

• Skeletal

• Smooth

• Cardiac