Which circulatory system of vessels provides the heart

The heart has four chambers — two on top and two on bottom: The two bottom chambers are the right ventricle and the left ventricle. These pump blood out of the heart. A wall called the interventricular septum is between the two ventricles.

The two top chambers are the right atrium and the left atrium. They receive the blood entering the heart. A wall called the interatrial septum is between the atria.

The atria are separated from the ventricles by the atrioventricular valves: The tricuspid valve separates the right atrium from the right ventricle. The mitral valve separates the left atrium from the left ventricle. Two valves also separate the ventricles from the large blood vessels that carry blood leaving the heart: The pulmonic valve is between the right ventricle and the pulmonary artery, which carries blood to the lungs.

The aortic valve is between the left ventricle and the aorta, which carries blood to the body. What Are the Parts of the Circulatory System? Two pathways come from the heart: The pulmonary circulation is a short loop from the heart to the lungs and back again. The systemic circulation carries blood from the heart to all the other parts of the body and back again. In pulmonary circulation: The pulmonary artery is a big artery that comes from the heart. It splits into two main branches, and brings blood from the heart to the lungs.

At the lungs, the blood picks up oxygen and drops off carbon dioxide. The blood then returns to the heart through the pulmonary veins. In systemic circulation: Next, blood that returns to the heart has picked up lots of oxygen from the lungs. So it can now go out to the body. The aorta is a big artery that leaves the heart carrying this oxygenated blood.

Branches off of the aorta send blood to the muscles of the heart itself, as well as all other parts of the body. Like a tree, the branches gets smaller and smaller as they get farther from the aorta.

At each body part, a network of tiny blood vessels called capillaries connects the very small artery branches to very small veins. The capillaries have very thin walls, and through them, nutrients and oxygen are delivered to the cells. Blood Blood consists of: Red blood cells — to carry oxygen White blood cells — that make up part of the immune system Platelets — needed for clotting Plasma — blood cells, nutrients and wastes float in this liquid.

The heart The heart pumps blood around the body. It sits inside the chest, in front of the lungs and slightly to the left side. The heart is actually a double pump made up of four chambers, with the flow of blood going in one direction due to the presence of the heart valves. The contractions of the chambers make the sound of heartbeats. The right side of the heart The right upper chamber atrium takes in deoxygenated blood that is loaded with carbon dioxide.

The blood is squeezed down into the right lower chamber ventricle and taken by an artery to the lungs where the carbon dioxide is replaced with oxygen. The left side of the heart The oxygenated blood travels back to the heart, this time entering the left upper chamber atrium. It is pumped into the left lower chamber ventricle and then into the aorta an artery. The blood starts its journey around the body once more.

Blood vessels Blood vessels have a range of different sizes and structures, depending on their role in the body. Arteries Oxygenated blood is pumped from the heart along arteries, which are muscular. Arteries divide like tree branches until they are slender. The largest artery is the aorta, which connects to the heart and picks up oxygenated blood from the left ventricle. The only artery that picks up deoxygenated blood is the pulmonary artery, which runs between the heart and lungs.

Capillaries The arteries eventually divide down into the smallest blood vessel, the capillary. Capillaries are so small that blood cells can only move through them one at a time. Oxygen and food nutrients pass from these capillaries to the cells.

Capillaries are also connected to veins, so wastes from the cells can be transferred to the blood. A unique electrical conduction system in the heart causes it to beat in its regular rhythm. The sinoatrial or SA node, a small area of tissue in the wall of the right atrium, sends out an electrical signal to start the contracting of the heart muscle. This node is called the pacemaker of the heart because it sets the rate of the heartbeat and causes the rest of the heart to contract in its rhythm.

These electrical impulses cause the atria to contract first, and then travel down to the atrioventricular or AV node, which acts as a kind of relay station. From here the electrical signal travels through the right and left ventricles, causing them to contract and forcing blood out into the major arteries.

In the systemic circulation, blood travels out of the left ventricle, to the aorta, to every organ and tissue in the body, and then back to the right atrium.

The arteries, capillaries, and veins of the systemic circulatory system are the channels through which this long journey takes place. Once in the arteries, blood flows to smaller arterioles and then to capillaries. Blood then goes back through the capillaries into venules, and then to larger veins until it reaches the vena cavae. Blood from the head and arms returns to the heart through the superior vena cava, and blood from the lower parts of the body returns through the inferior vena cava.

Both vena cavae deliver this oxygen-depleted blood into the right atrium. From here the blood exits to fill the right ventricle, ready to be pumped into the pulmonary circulation for more oxygen. In the pulmonary circulation, blood low in oxygen but high in carbon dioxide is pumped out the right ventricle into the pulmonary artery, which branches off in two directions.

The right branch goes to the right lung, and vice versa. In the lungs, the branches divide further into capillaries. Blood flows more slowly through these tiny vessels, allowing time for gases to be exchanged between the capillary walls and the millions of alveoli, the tiny air sacs in the lungs.

During the process called oxygenation, oxygen is taken up by the bloodstream. Oxygen locks onto a molecule called hemoglobin in the red blood cells. The newly oxygenated blood leaves the lungs through the pulmonary veins and heads back to the heart. It enters the heart in the left atrium, then fills the left ventricle so it can be pumped into the systemic circulation.

Problems with the cardiovascular system are common — more than 64 million Americans have some type of cardiac problem. Heart and circulatory problems are grouped into two categories: congenital problems present at birth and acquired problems developed some time after birth.

Congenital heart defects. Approximately 8 out of every 1, newborns have congenital heart defects ranging from mild to severe. Some congenital heart defects are caused by genetic disorders, but most are not. What all congenital heart defects have in common, however, is that they involve abnormal or incomplete development of the heart.

Other murmurs can be caused by congenital heart defects or other heart conditions. Cardiac arrhythmias, also called dysrhythmias or rhythm disorders, are problems in the rhythm of the heartbeat. They may be caused by a congenital heart defect or they may be acquired later. Arrhythmias can occur at any age and may be discovered during a routine physical examination. Depending on the type of rhythm disorder, an arrhythmia may be treated with medication, surgery, or pacemakers.

Some arrhythmias are not harmful. This chronic disease causes the heart muscle the myocardium to become weakened. Usually, it first affects the lower chambers of the heart, the ventricles, and then progresses and damages the muscle cells and even the tissues surrounding the heart.

In its most severe forms, it can lead to heart failure and even death. Cardiomyopathy is the 1 reason for heart transplants in children. Coronary artery disease. The most common heart disorder in adults, coronary artery disease is caused by atherosclerosis.

Deposits of fat, calcium, and dead cells, called atherosclerotic plaques, form on the inner walls of the coronary arteries the blood vessels that supply the heart and interfere with the smooth flow of blood. Blood flow to the heart muscle may even stop if a thrombus, or clot, forms in a coronary vessel, which may cause a heart attack. If the clot can be dissolved within a few hours, damage to the heart can be reduced.

Heart attacks are rare in kids and teens. Hypercholesterolemia high cholesterol. Having too much cholesterol in the blood, also known as hypercholesterolemia, is a major risk factor for heart disease and can lead to a heart attack. Cholesterol is carried in the bloodstream by lipoproteins. High blood pressure hypertension. Over time, high blood pressure can damage the heart, arteries, and other body organs.

Symptoms can include headache, nosebleeds, dizziness, and lightheadedness.