This positively charged ion is in highest concentrations outside of cells:

a. sodium

The resting membrane is permeable to:

b. potassium

The part of the neuron that receives nervous signals is called the:

b. dendrite

The resting membrane potential is:

a. —70 mV (more negative inside)

The diagram below depicts the neuron in:

B. PEAK OF THE ACTION POTENTIAL

The diagram below is a picture of:

b. a sarcomere

The action potential is when:

b. the membrane potential rapidly becomes more positive +30-50 mV then returns to a negative value

In the action potential, which of the following is the correct order of events:

a. threshold potential, opening of voltage gated sodium channels, opening of voltage gated potassium channels

The diagram below shows tropomyosin and calmodulin. Which of the following is true:

a. myosin cannot bind to actin in this state

Tetrodotoxin blocks:

c. voltage gated sodium channels

Propagation of action potentials can be increased in speed by:

b. having schwann cells and nodes in between them

the speed of action potentials is as fast as:

b. 225 mph

when the action potential gets to the end of the axon, this causes:

a. vesicles containing neurotransmitter to release into the synaptic cleft

The signal that tells vesicles containing neurotransmitter to migrate to the axon terminal surface and release their contents is:

a. increased calcium

In the case of motor neurons that innervate muscle cells, the binding of neurotransmitter to the muscle cell causes:

a. the T tubules to release calcium

The sarcomere is comprised of two major proteins

c. myosin and actin

The binding sites on actin are blocked in muscle in the resting (non-contracting) state by:

b. tropomyosin

The binding of calcium to calmodulin causes:

a. tropomyosin to pull away from actin

ATP causes:

c. myosin to detach from actin

In sarcomere shortening, the muscle contracts (shortens) by:

c. myosin pulling on actin

Fast twitch muscle fibers shorten quickly and rely on anaerobic metabolism. These fibers are called:

b. type II

Smooth muscle:

c. is an involuntary muscle found in organs like the small intestine

The thick filament is made of:

b. myosin

The picture below is of:

c. striated (skeletal) muscle

Low serotonin is linked to:

a. clinical depression

Dopamine is linked to:

b. schizophrenia

Which of the following is the type of myosin in slow twitch muscle fibers:

a. type I