A student researching the human heart has taken notes:

• The heart beats about 100,000 times per day • Blood flows through a complex network of vessels • The heart has four chambers that coordinate pumping • Electrical signals regulate the heartbeat rhythm • Cardiovascular disease is a leading cause of death worldwide

4
reading

The student wants to explain how the heart maintains its constant rhythm.

A

The human heart beats approximately 100,000 times every day.

B

Cardiovascular disease is a leading cause of death worldwide.

C

The heart maintains its constant rhythm through electrical signals that coordinate the four chambers' pumping sequence.

D

Blood flows through the body via a complex network of vessels.

Correct Answer: C

Choice C. Electrical signals coordinating chambers explains rhythm maintenance.