Circulatory System: Facts, Function & Diseases
The circulatory system is a vast network of organs and vessels that is responsible for the flow of blood, nutrients, oxygen and other gases,
and hormones to and from cells. Without the circulatory system, the body would not be able to fight disease or maintain a stable internal environment — such as proper temperature and pH — known as homeostasis.
Description of the circulatory system
While many view the circulatory system as simply a highway for blood — it is also known as the cardiovascular system — it is made up of three independent systems that work together: the heart (cardiovascular), lungs (pulmonary) and arteries, veins, coronary and portal vessels (systemic).
In the average human, about 2,000 gallons (7,572 liters) of blood travel daily through about 60,000 miles (96,560 kilometers) of blood vessels. An average adult has 5 to 6 quarts (4.7 to 5.6 liters) of blood, which is made up of plasma, red blood cells, white blood cells and platelets. In addition to
blood, the circulatory system moves lymph, which is a clear fluid that helps rid the body of unwanted material.
The heart, blood, and blood vessels make up the cardiovascular component of the circulatory system. It includes the pulmonary circulation, a "loop" through the lungs where blood is oxygenated. It also incorporates the systemic circulation, which runs through the rest of the body to provide oxygenated blood.
The pulmonary circulatory system sends oxygen-depleted blood away from the heart through the pulmonary artery to the lungs and returns oxygenated blood to the heart through the pulmonary vein.
Oxygen-deprived blood enters the right atrium of the heart and flows through the tricuspid valve (right atrioventricular valve) into the right ventricle.
From there it is pumped through the pulmonary semilunar valve into the pulmonary artery on its way to the lungs. When it gets to the lungs, carbon dioxide is released from the blood and oxygen is absorbed. The pulmonary vein sends the oxygen-rich blood back to the heart.
The systemic circulation is the portion of the circulatory system is the network of veins, arteries and blood vessels that transports blood from heart,
services the body's cells and then re-enters the heart.
Diseases of the circulatory system
According to the American Heart Association, cardiovascular disease is the leading cause of death in the United States. Because of its vastness and
critical nature, it is one of the systems of the body most prone to disease.
One of the most common diseases of the circulatory system is arteriosclerosis, in which the fatty deposits in the arteries causes the walls
to stiffen and thicken the walls. The causes are too much fat, cholesterol and calcium. This can restrict blood flow or in severe cases stop it all together,
resulting in a heart attack or stroke.
Another circulatory is disease, hypertension — commonly called high blood pressure — causes the heart to work harder and can lead to such complications as a heart attack, a stroke, or kidney failure.
An aortic aneurysm occurs when the aorta is damaged and starts to bulge or eventually tear, which can cause severe internal bleeding. This weakness can be present at birth or the result of atherosclerosis, obesity, high blood pressure or a combination of these conditions.
The circulatory system is a vast network of organs and vessels that is responsible for the flow of blood, nutrients, oxygen and other gases,
and hormones to and from cells. Without the circulatory system, the body would not be able to fight disease or maintain a stable internal environment — such as proper temperature and pH — known as homeostasis.
Description of the circulatory system
While many view the circulatory system as simply a highway for blood — it is also known as the cardiovascular system — it is made up of three independent systems that work together: the heart (cardiovascular), lungs (pulmonary) and arteries, veins, coronary and portal vessels (systemic).
In the average human, about 2,000 gallons (7,572 liters) of blood travel daily through about 60,000 miles (96,560 kilometers) of blood vessels. An average adult has 5 to 6 quarts (4.7 to 5.6 liters) of blood, which is made up of plasma, red blood cells, white blood cells and platelets. In addition to
blood, the circulatory system moves lymph, which is a clear fluid that helps rid the body of unwanted material.
The heart, blood, and blood vessels make up the cardiovascular component of the circulatory system. It includes the pulmonary circulation, a "loop" through the lungs where blood is oxygenated. It also incorporates the systemic circulation, which runs through the rest of the body to provide oxygenated blood.
The pulmonary circulatory system sends oxygen-depleted blood away from the heart through the pulmonary artery to the lungs and returns oxygenated blood to the heart through the pulmonary vein.
Oxygen-deprived blood enters the right atrium of the heart and flows through the tricuspid valve (right atrioventricular valve) into the right ventricle.
From there it is pumped through the pulmonary semilunar valve into the pulmonary artery on its way to the lungs. When it gets to the lungs, carbon dioxide is released from the blood and oxygen is absorbed. The pulmonary vein sends the oxygen-rich blood back to the heart.
The systemic circulation is the portion of the circulatory system is the network of veins, arteries and blood vessels that transports blood from heart,
services the body's cells and then re-enters the heart.
Diseases of the circulatory system
According to the American Heart Association, cardiovascular disease is the leading cause of death in the United States. Because of its vastness and
critical nature, it is one of the systems of the body most prone to disease.
One of the most common diseases of the circulatory system is arteriosclerosis, in which the fatty deposits in the arteries causes the walls
to stiffen and thicken the walls. The causes are too much fat, cholesterol and calcium. This can restrict blood flow or in severe cases stop it all together,
resulting in a heart attack or stroke.
Another circulatory is disease, hypertension — commonly called high blood pressure — causes the heart to work harder and can lead to such complications as a heart attack, a stroke, or kidney failure.
An aortic aneurysm occurs when the aorta is damaged and starts to bulge or eventually tear, which can cause severe internal bleeding. This weakness can be present at birth or the result of atherosclerosis, obesity, high blood pressure or a combination of these conditions.