Skeletal Muscle Physiology 2

Tetanic contraction is produced when repeated stimuli is administered during which part of the muscle twitch?

• 1. Relaxation period

• 1. Contraction period

• 1. Wave period

• 1. Relief period

An isolated muscle is stimulated with increasing stimulus strength. Stimuli of 10, 15 and 20 mV produced no response, while 25 mV produced a small contraction. Which of the following is the threshold stimulation?

• 1. 10 mV

• 1. 15 mV

• 1. 20 mV

• 25 mV

In the myofibril, ATP is used for which of the following?

• Na+ K+ pump

• muscle contraction

• muscle relaxation

• All of the options are correct

Triads in skeletal muscle consist of which of the following?

• sarcoplasm, sarcoplasmic reticulum, calcium ions

• sarcoplasmic reticulum, terminal cisterna, sarcoplasm

• two terminal cisternae and a T-tubule.

• two T-tubules and one terminal cisterna

In a muscle twitch, which of the following represents the time between application of a stimulus and the beginning of contraction?

• treppe

• tetany

• lag

• relaxation

Which of the following would represent incomplete tetanus?

• multiple contractions with no relaxation

• multiple contractions with slight relaxation

• multiple contractions followed by a long rest period

• a long rest period before contractions start

Which of the following best describes the role of T-tubules in muscle contraction?

• Conducting action potentials deep into the muscle fiber

• Storing calcium ions for release during contraction

• Producing energy for muscle relaxation

• Regulating the synthesis of myosin filaments

What is the significance of the neuromuscular junction in muscle physiology?

• It is the site where muscle fibers store excess energy

• It is where motor neurons communicate with muscle fibers

• It is responsible for the production of creatine phosphate

• It regulates the release of lactic acid during exercise

Which of the following types of muscle fatigue represents depletion of ATP?

• psychological

• synaptic

• peripheral

• muscular