The Circulatory System

by Arnaud V and Chaden L

• Aorta

• The Left Atrium

• The Right Atrium

• The Left Ventricle

• The Right Ventricle

• Epicardium, Pericardium, Endocardium

• Atrioventricular Valves

• Semilunar Valves

The Heart

General Info:• The heart has 4 hollow chamber: 2 atria and 2 ventricles• Each chamber is lined with endocardium

Atria:• Are primarily receiving chambers• Blood enters the atria under low pressure and flows down

to the ventricles

Ventricles:• Are primarily discharging chambers• Pump the blood out of the heart and into circulation

Atria and Ventricles

There are two sets of valves: The Atrioventricular Valves (AV) and Semilunar Valves

Atrioventricular Valves• Located between the atrial and ventricular chambers• Left AV valve is the Bicuspid valve (Also called the Mitral

Valve)• Right AV valve is the Tricuspid valve

Semilunar Valves• Guard the base of the 2 large

arteries leaving the heart• Called the Pulmonary Valve and

Aortic Semilunar Valve

The Four Valves

• ____A____

• ____B____

• ____C____

• ____D____

• ____E____

• Epicardium, Pericardium, Endocardium

• Atrioventricular Valves

• Semilunar Valves

Heart Diagram Practice

• Pulmonary Circuit• Pulmonary Arteries• Pulmonary Veins• Venae Cavae• Aorta and Branches

• Blue = Oxygen poor• Red = Oxygen rich

The Circulatory System

Pulmonary Circuit• From right side of heart to the lungs and back to the left

side• Carries blood to the lungs for gas exchange and then

returns it to the heart

Systemic Circuit• From the left side of heart through body tissues and back

to the right side• Supplies all oxygen and nutrient-rich blood to all body

organs• Left ventricle walls are substantially thicker than right

ventricle because the blood needs to be pumped so much farther, it is also a much stronger pump

Pulmonary/Systemic Circuits

Coronary Arteries :An artery supplying blood to the heart.

Coronary Sinus: A wide venous channel about 2.25 centimeters in

length that receives blood from the coronary veins and empties into the right atrium of the heart.

Cardiac VeinsCardiac veins contain valves preventing back flow; a

Thebesian valve may or may not cover the ostium of the coronary sinus.

Cardiac Circulation

Angina Pectoris• Crushing chest pain• Caused because myocardium is deprived of oxygen• Should never be ignored, can lead to myocardial infarction

Myocardial Infarction• Commonly known as a "heart attack"• Occurs when an angina is prolonged/ignored• The ischemic heart cells die, forming an infarct

Problems in the Circulatory System