Chapter 1: Cardiac, Vascular, and Pulmonary Systems

CLINICAL APPLICATION OF FOUNDATIONAL SCIENCES

OVERVIEW

In understanding the human body movement system, the principles of moving blood, nutrients, ions, oxygen (O₂), carbon dioxide (CO₂), metabolic byproducts, and waste, producing electrical gradients, and generating differences in pressure are fundamental in the functioning of the cardiac, vascular, and pulmonary systems. In terms of physiology, it is the action at the cellular level of these organ systems that allows for the transport, movement, and functioning of the systems in everyday life, activity, and exercise. In addition, the introduction and use of pharmacological agents has an influence on the movement of these systems when needed in instances of pathology and/or disease.

ANATOMY AND PHYSIOLOGY OF THE CARDIAC AND VASCULAR SYSTEMS

Chambers of the Heart

There are four distinct chambers of the heart (Figure 1–1). The chambers’ work can be divided into two pairs that essentially serve as two pumps to the lungs (pulmonary circulation) and to the rest of the body (systemic circulation). The action of the heart and myocardium moves and circulates blood throughout the body.

• Right atrium (RA): Receives blood from the systemic circulation via the superior and inferior vena cave. Also receives blood from the coronary sinus (coronary circulation).

• Right ventricle (RV): Delivers blood received from the RA in the lungs and the pulmonary system via the pulmonary artery.

• Left atrium (LA): Receives oxygenated blood from the lungs and the pulmonary system via four pulmonary veins.

  Left ventricle (LV): Delivers the blood received from the LA to the rest of the body (systemic circulation) via the aorta.

• Atrioventricular (AV) valves: Prevent backflow of blood from the ventricle back into the atria. The AV valves are reinforced by structures called chordae tendineae and papillary muscles.

  • Tricuspid valve is found on the right side of the heart between the RA and RV.

  • Bicuspid valve (mitral valve) is found on the left side of the heart between the LA and LV.

• Semilunar (SL) valves: Prevent backflow toward the ventricles.

  • Pulmonary valve: Prevents backflow into the RV from the pulmonary artery.

  • Aortic valve: Prevents backflow into the LV from the aorta.