M.S Cardio

Bulacan State University

COLLEGE OF NURSING

City of Malolos, Bulacan

Medical-Surgical Nursing

THE CARDIOVASCULAR SYSTEM

Most simply stated, the major function of the cardiovascular system is transportation. Using blood as the transport vehicle, the system carries oxygen, nutrients, cell wastes, hormones and many other substances vital for body homeostasis to and from the cells. The force to move the blood around the body is provided by the beating of the heart.

I. The Heart

A. Covering and Wall

* Pericardium – a double sac of serous membrane that encloses the heart: visceral pericardium or epicardium and the parietal pericardium.

* 3 layers of the Heart Wall:

a. Outer epicardium

b. Myocardium

c. Endocardium

B. 4 Hollow Chambers or Cavities:

a. Superior atria/ left and right atrium – “receiving chambers”

b. Inferior ventricles/ left and right ventricle – “discharging chambers”; actual pumps of the heart

C. Great Vessels:

a. Superior and inferior venae cavae – it delivers oxygen-poor blood into the right atrium

b. Pulmonary artery or trunk – it delivers oxygen-poor blood pumped by the right ventricle into the lungs.

c. Four Pulmonary veins (left and right) – it delivers blood oxygenated by the lungs into the left atrium

d. Aorta – it delivers oxygenated blood pumped by the left side (left ventricle) of the heart.

D. Four Valves of the Heart

a. Atrioventricular or AV valves – located between the atria and ventricles on each side; it prevent backflow into the atria when the ventricles contract; 2 types of AV valves include:

* Left AV valve or bicuspid valve or mitral valve

* Right AV valve or tricuspid valve, has three cusps

b. Semilunar valve – guards the bases of the two large arteries leaving the ventricular chambers. This prevents arterial blood from reentering the heart.

* Pulmonary semilunar valve – it prevents backflow of blood into the right ventricle after it pumps.

* Aortic semilunar valve...