____ 22. The action potential
a. is a chemical that diffuses across a synapse.
b. transmits information from the cell body to the axon through thesynapse.
c. is an electric current that passes through the axon and causesthe release of neurotransmitters into
the synapse.
____ 24. Humans need _________ to move parts of the appendicularskeleton, such as the arm.
a. muscles
b. bones
c. joints
____ 25. An MRI reveals that a patient’s heart valves are inflamed.Doctor A says that the patient has coronary artery
disease. Doctor B says that the patient has rheumatic fever. Whichdoctor is most likely correct?
a. Doctor A, because the heart valves pump blood into coronaryarteries.
b. Doctor B, because antibodies attack heart valves in rheumatoidfever.
c. Doctor A, because arterial clogging leads to hear valvefatigue.
____ 26. Which lists the layers of skin from outer to inner?
a. dermis, melanin
b. epidermis, dermis
c. melanin, epidermis
____ 27. A doctor find that her patient’s white blood cell count ishigher than normal. What does this most likely
indicate?
a. The patient is healthy.
b. The patient has an infection.
c. The patient’s kidneys are functioning poorly.
