Midterm #2 Review

Which of the following myofilaments makes up the thick filament?

• Actin

• Myosin

• Troponin

• Tropomyosin

What type of channel is found at the motor end plate of the muscle fiber?

• Voltage-gated Na+ channel

• Voltage-gated Ca2+ channel

• Ligand-gated Na+ channel

• Ligand-gated Ca2+ channel

Answer explanation

Which of the following changes occurs within a muscle cell after resistance training?

• An increase in the number of oxidative enzymes

• An increase in the number of myofibrils

• An increase in fatigue resistance

• A decrease in the size of myofibrils

Select all that apply: These muscle cells are striated.

• Skeletal

• Cardiac

• Smooth

What kind of neuron is pictured?

• Multipolar

• Bipolar

• Unipolar

• Pseudounipolar

Answer explanation

Multipolar neurons have one axon and 2+ dendrites. The motor neurons in the human body are considered to be multipolar.

Which of the following neurons will propagate an action potential the fastest?

• A neuron with a small unmyelinated axon.

• A neuron with a small myelinated axon.

• A neuron with a large unmyelinated axon.

• A neuron with a large myelinated axon.

What part of the sarcomere is letter "e" identifying?

• The I band

• The H zone

• The A band

• The Zone of Overlap

Which of the following processes of ATP generation does NOT take place in the cytosol?

• Creatine phosphate hydolysis

• Glycolysis (Anaerobic metabolism)

• Oxidative metabolism (Aerobic metabolism)

• All 3 processes take place within the cytosol.

Answer explanation

Oxidative metabolism of both carbohydrate and fat takes place inside the mitochondria of muscle cells.

Select all the apply: Which of the following could lead to hyperpolarization of the axolemma?

• Opening of ligand-gated K⁺ channels

• Opening of ligand-gated Na⁺ channels

• Opening of ligand-gated Cl^- channels

• Opening of voltage-gated Na⁺ channels

Answer explanation

When ___ binds to myosin, the myosin head detaches from actin.

• ATP

• ADP

• Inorganic phosphate (Pi)

• Ca2+