40. Circulatory System

SCIENTIFIC THINKING The studies described in Module 23.6 were funded by both government agencies and major pharmaceutical and medical supply companies. NIH grants for research on heart disease total more than $1.2 billion per year. Gather more information and form an opinion on how heart disease research should be funded, whether by private enterprises such as pharmaceutical companies, donor-supported nonprofit organizations, or government agencies. Write an essay arguing your point of view.

Which chamber(s) of a human heart receive(s) and pump(s) oxygenated blood?

Heart valves function to __________.

What is the physiological cause of a heart attack?

Blood leaves the inferior vena cava and flows directly into the __________.

Pressure is greatest in the ventricles when __________.

The SA node generates an electrical impulse from its location in __________.

A recording of the electrical activity of a patient's heart shows that the atria are contracting regularly and normally, but every few beats the ventricles fail to contract. Which of the following is probably functioning improperly?

Your blood pressure is 120/70. The "120" indicates __________, and the "70" indicates __________.

When we compare the structures and functions of arteries and veins, we find that the walls of arteries are __________, the blood pressure inside arteries is __________, and the blood in arteries is moving __________ the heart.