Muscle Unit Test

What changes occur in the muscle when people "train"?

• more mitochondria

• more capillaries

• more lactic acid

• both a and b

Which of the following statements is false?

• ATP can be made through 3 ways in the body.

• Aerobic respiration can supply energy for hours.

• Direct phosphorylation requires oxygen.

• Anaerobic glycolysis causes lactic acid build up.

What type of contraction causes actual shortening of the muscle?

• isometric

• isotoner

• isotonic

• isometer

What object/chemical binds to the troponin on the actin which causes the exposure of the binding sites for the myosin cross bridges?

• Ach

• ATP

• Ca²⁺

• Na¹⁺

The outermost layer of connective tissue surrounding a skeletal muscle is called:

• epimysium

• perimysium

• endomysium

• actin

Myofibrils are composed primarily of:

• actin and myosin

• sarcoplasmic reticulum

• muscle fibers

• fascicles

In order for a muscle to relax, what must happen?

• Acetylcholinesterase must break down Ach.

• Calcium must leave the sarcoplasmic reticulum.

• Myosin must link onto the actin.

• None of the above

The striated appearance of skeletal muscle is due to:

• transverse tubule pattern

• cisternae placement

• actin and myosin overlap

• sarcoplasmic reticulum network

Which of the following is NOT true when comparing fast twitch and slow twitch muscle types?

• red muscle fibers are better suited for endurance activities

• red muscle fibers have a large amount of blood supply

• red muscle fibers depend on anaerobic respiration

• red muscle fibers fatigue slower than white

How does the motor neuron communicate with the muscle?

• sign language

• neurotransmitters

• neurotransports

• neuromoto enzymes