The Human Heart Two Pumps in

Like all other mammalian hearts, the human heart has four chambers: two atria and two ventricles (Figure 49.3). The atrium and ventricle on the right side of your body are called

49.3 The Human Heart and Circulation In the human heart, blood flows from right heart to lungs to left heart to body. The atrioventricular valves prevent blood from flowing back into the atria when the ventricles contract. The pulmonary and aortic valves prevent blood from flowing back into ventricles from the arteries when the ventricles relax.

Aorta

Pulmonary valve

Pulmonary artery

To lung

Vessels shown in blue bring deoxygenated blood from the body to the right heart, which pumps it to the lungs for oxygenation.

Aorta

Pulmonary valve

Pulmonary artery

To lung

Pulmonary Circuit

From lung

Pulmonary veins

From the pulmonary circuit, the blood returns to the left atrium.

... and flows through an atrioventricular valve into the left ventricle.

The left ventricle pumps blood into the systemic circuit.

2l... and flows through an atrioventricular valve into the right ventricle.

^ The right ventricle pumps the blood into the pulmonary circuit.

Inferior vena cava

Aortic valve

From lung

Pulmonary veins

From the pulmonary circuit, the blood returns to the left atrium.

2l... and flows through an atrioventricular valve into the right ventricle.

^ The right ventricle pumps the blood into the pulmonary circuit.

... and flows through an atrioventricular valve into the left ventricle.

The left ventricle pumps blood into the systemic circuit.

Inferior vena cava

Aortic valve the right heart. The atrium and ventricle on the left side of your body are called the left heart. The right heart pumps blood through the pulmonary circuit, and the left heart pumps blood through the systemic circuit.

Valves between the atria and ventricles, the atrioventricular valves, prevent backflow of blood into the atria when the ventricles contract. The pulmonary valve and the aortic valve, positioned between the ventricles and the major arteries, prevent the backflow of blood into the ventricles.

In this section, we'll first focus on the flow of blood through the heart and through the body. Then we'll examine the unique electrical properties of cardiac muscle that result in the heartbeat, and we'll see how the heart's electrical activity can be recorded in an EKG (electrocardiogram).

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Essentials of Human Physiology

Essentials of Human Physiology

This ebook provides an introductory explanation of the workings of the human body, with an effort to draw connections between the body systems and explain their interdependencies. A framework for the book is homeostasis and how the body maintains balance within each system. This is intended as a first introduction to physiology for a college-level course.

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Responses

  • ABELINO GALLO
    Which chamber receives oxygenated blood from the pulmonary circuit?
    8 years ago
  • Kathrin
    Do the pulmonary and aortic valves prevent backflow from arteries to ventricles?
    8 years ago
  • Mhret
    Which side of the human heart pumps blood to the systemic circuit?
    8 years ago

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