4 Chambered Heart Anatomy and Physiology

Heart Anatomy
Source: http://www.yale.edu/imaging/echo_atlas/references/heart_anatomy.html

The purpose of the heart is to pump blood through blood vessels, arteries, and veins to all parts of our body. The inside of the heart is divided into four chambers
-The top two chambers are called the atria and are collection chambers for blood.
-The bottom two chambers are called the ventricles and receive blood from the atria and pump into the lungs and body.
-There are four valves, Tricuspid (right A-V) valve, Bicuspid (Left A-V or Mitral) valve, Pulmonary valve, and Aortic valve, which connect the chambers

How Does the Heart Work?
Circulation begins at the right side of the heart where blood from the body comes to the right atrium. The blood passes to the right ventricle through the tricuspid valve, in which the blood is pumped into the lungs through the pulmonary valve to receive oxygen.

The blood is delivered by the pulmonary arteriole to the lungs. In the lungs, the blood is oxygenated in the alveolar capillary network. After oxygenation, the blood is backed to the left atrium by Pulmonary venule.

Gas exchange in Lungs
Source: http://hyperphysics.phy-astr.gsu.edu/hbase/biology/respir.html

The oxygenated blood enters from two veins from the left lung and four veins from the right lung which merge into two before they enter the atrium.

From the left atrium, the oxygenated blood passes through the bicuspid valve into the left ventricle

From the left ventricle, oxygenated blood flows through the aortic valve into the aorta

Just superior to the valve, two arteries branch off to feed the heart. These are called the right and left coronary arteries. The coronary artery bifurcates to become the circumflex artery which feed the back of the heart. Deoxygenated blood is sent back to the coronary sinus into the right atrium to become reoxygenated in lungs.

Coronary Artery
Source: http://www.umm.edu/patiented/articles/coronary_artery_balloon_angioplasty_normal_anatomy_000127.htm

Beyond where the coronary arteries leave the aorta, three branches head off the aortic arch . One of these branches to supply the right arm and right carotid, one flows to the left carotid, and one supplies the left arm

Right Carotid
Source::http://www.umm.edu/patiented/articles/carotid_artery_surgery_normal_anatomy_000124.htm

Beyond the aortic arch, the aorta descends down behind the heart (descending aorta) where it eventually bifurcates into right and left illiac arteries which become femoral arteries.

Illiac Arteries
Source:http://www.jtmedart.com/Portfolio/12

Through this systematic circuit, arteries become smaller arterioles which become capillaries where Oxygen and Carbon dioxide are exchanged deoxygenated blood return through venules which turn into veins which return blood to the right atrium

Source: Lectured by Mr. Rick Ceriale.