The Circulatory System Overview

The Circulatory System

• The circulatory system is made up of three main parts: the heart, blood vessels, and blood.
• The heart is a muscular organ that pumps blood throughout the body.
• The heart is located in the chest cavity between the lungs.
• It is about the size of a fist.
• The heart beats approximately 100,000 times per day.
• The heart pumps about 5-6 quarts of blood each minute.
• This equates to approximately 2,000 gallons of blood pumped each day.
• The pericardium is a protective sac surrounding the heart.
• Dr. William Harvey was the first to recognize the full circulation of blood in the human body.
• The heart has four chambers: two atria and two ventricles.
• The atria are the receiving chambers for blood entering the heart.
• The ventricles pump blood out of the heart.
• The septum is the wall that divides the right and left sides of the heart.

Blood Vessels

• Blood vessels are responsible for transporting blood around the body.
• There are three types of blood vessels: arteries, veins, and capillaries.
• Arteries carry blood away from the heart.
• Veins carry blood towards the heart.
• Capillaries are small, twig-like structures that connect arteries and veins.
• The superior vena cava carries blood from the upper extremities to the right atrium.
• The inferior vena cava carries blood from the lower extremities to the right atrium.
• The aorta is the largest artery in the body.
• Venules are the smallest veins in the body.

Blood

• Blood is a tissue made of red blood cells, white blood cells, platelets, and other substances suspended in plasma.
• Blood carries oxygen and nutrients to the tissues, and removes waste products.