Heart and Circulatory Systemenparentshttps://kidshealth.org/EN/images/headers/P-heartBB-enHD-AR1.gifThe heart and circulatory system are our body's lifeline, delivering blood to the body's tissues. Brush up on your ticker with this body basics article.heart, circulatory system, heart disease, heart defect, oxygen, blood, arteries, capillaries, pulomonary artery, coronary, coronary arteries, cardiovascular system, cardiovascular health, heartbeat, heart beat, ventricles, atria, aorta, veins, systole, diastole, alveoli, congenital heart defects, congenital heart defect, acquired heart defects, heart defects, heart murmur, heart murmurs, arrhythmias, dysrhythmias, rhythm disorders, cardiomyopathy, coronary artery disease, heart attack, hyperlipidemia, hypercholesterolemia, high cholesterol, hypertension, high blood pressure, blood pressure, kawasaki disease, mucocutaneous lymph node syndrome, myocarditis, aneurysms, rheumatic heart disease, stroke, heart health, healthy heart, cholesterol, exercise, obesity, healthy diet, healthy eating, CD1Congenital Heart Defects, CD1Cardiology, CD1Heart Transplants,CD1Cardiac Catheterization, CD1Heart Surgery, CD1Congenital Heart Defects, CD1Cardiology, CD1Heart Transplants,CD1Cardiac Catheterization, CD1Heart Surgery, CD1Coarctation of the Aorta, CD1AtrialSeptal Defect, CD1Patent Ductus Arteriosus, CD1Tetrology of Fallot, CD1Ventricular Septal Defect07/06/200009/14/201809/02/2019Larissa Hirsch, MD09/04/201852398b6a-54a6-4272-a569-42ed5b12aeachttps://kidshealth.org/ws/RadyChildrens/en/parents/heart.html/<h3>What Does the Heart Do?</h3> <p>The heart is a pump, usually beating about 60 to 100 times per minute. With each heartbeat, the heart sends <a href="https://kidshealth.org/ws/RadyChildrens/en/parents/blood.html/">blood</a> throughout our bodies, carrying oxygen to every cell. After delivering the oxygen, the blood returns to the heart. The heart then sends the blood to the <a href="https://kidshealth.org/ws/RadyChildrens/en/parents/lungs.html/">lungs</a> to pick up more oxygen. This cycle repeats over and over again.</p> <h3>What Does the Circulatory System Do?</h3> <p>The circulatory system is made up of blood vessels that carry blood away from and towards the heart. <strong>Arteries</strong> carry blood away from the heart and <strong>veins</strong> carry blood back to the heart.</p> <p>The circulatory system carries oxygen, nutrients, and hormones to cells, and removes waste products, like carbon dioxide. These roadways travel in one direction only, to keep things going where they should.</p> <h3>What Are the Parts of the Heart?</h3> <p>The heart has four chambers — two on top and two on bottom:</p> <ul class="kh_longline_list"> <li>The two bottom chambers are the <a class="kh_anchor">right ventricle</a> and the <a href="https://kidshealth.org/ws/RadyChildrens/en/parents/dictionary-left-ventricle.html/">left ventricle</a>. These pump blood out of the heart. A wall called the <strong>interventricular septum</strong> is between the two ventricles.</li> <li>The two top chambers are the <a href="https://kidshealth.org/ws/RadyChildrens/en/parents/dictionary-right-atrium.html/">right atrium</a> and the <a href="https://kidshealth.org/ws/RadyChildrens/en/parents/dictionary-left-atrium.html/">left atrium</a>. They receive the blood entering the heart. A wall called the <strong>interatrial septum</strong> is between the atria.</li> </ul> <p><img class="right" title="" src="https://kidshealth.org/EN/images/illustrations/ASDestab_433x259_enIL.png" alt="Illustration: Healthy Heart" /></p> <p>The atria are separated from the ventricles by the <strong>atrioventricular valves:</strong></p> <ul class="kh_longline_list"> <li>The <strong>tricuspid valve</strong> separates the right atrium from the right ventricle.</li> <li>The <strong>mitral valve</strong> separates the left atrium from the left ventricle.</li> </ul> <p>Two valves also separate the ventricles from the large blood vessels that carry blood leaving the heart:</p> <ul class="kh_longline_list"> <li>The <strong>pulmonic valve</strong> is between the right ventricle and the pulmonary artery, which carries blood to the lungs.</li> <li>The <strong>aortic valve</strong> is between the left ventricle and the aorta, which carries blood to the body.</li> </ul> <h3>What Are the Parts of the Circulatory System?</h3> <p>Two pathways come from the heart:</p> <ul class="kh_longline_list"> <li>The <strong>pulmonary circulation</strong> is a short loop from the heart to the lungs and back again.</li> <li>The <strong>systemic circulation</strong> carries blood from the heart to all the other parts of the body and back again.</li> </ul> <p>In pulmonary circulation:</p> <ul> <li>The <a class="kh_anchor">pulmonary artery</a> 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.</li> </ul> <p>In systemic circulation:</p> <ul class="kh_longline_list"> <li>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 <a href="https://kidshealth.org/ws/RadyChildrens/en/parents/dictionary-aorta.html/">aorta</a> 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.<br /><br />At each body part, a network of tiny blood vessels called <strong>capillaries</strong> 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. Waste products are brought into the capillaries.<br /><br />Capillaries then lead into small veins. Small veins lead to larger and larger veins as the blood approaches the heart. Valves in the veins keep blood flowing in the correct direction. Two large veins that lead into the heart are the <a href="https://kidshealth.org/ws/RadyChildrens/en/parents/dictionary-svc.html/">superior vena cava</a> and <a href="https://kidshealth.org/ws/RadyChildrens/en/parents/dictionary-ivc.html/">inferior vena cava</a>. (The terms superior and inferior don't mean that one vein is better than the other, but that they're located above and below the heart.)<br /><br />Once the blood is back in the heart, it needs to re-enter the pulmonary circulation and go back to the lungs to drop off the carbon dioxide and pick up more oxygen.</li> </ul> <h3>How Does the Heart Beat?</h3> <p>The heart gets messages from the body that tell it when to pump more or less blood depending on a person's needs. For example, when we're sleeping, it pumps just enough to provide for the lower amounts of oxygen needed by our bodies at rest. But when we're exercising, the heart pumps faster so that our muscles get more oxygen and can work harder.</p> <p>How the heart beats is controlled by a system of electrical signals in the heart. The <strong>sinus</strong> (or sinoatrial) <strong>node</strong> is a small area of tissue in the wall of the right atrium. It sends out an electrical signal to start the contracting (pumping) 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.</p> <p>These electrical impulses make the atria contract first. Then the impulses travel down to the <strong>atrioventricular</strong> (or AV) <strong>node</strong>, which acts as a kind of relay station. From here, the electrical signal travels through the right and left ventricles, making them contract.</p> <p>One complete heartbeat is made up of two phases:</p> <ol class="kh_longline_list"> <li>The first phase is called <strong>systole</strong>&nbsp;(SISS-tuh-lee). This is when the ventricles contract and pump blood into the aorta and pulmonary artery. During systole, the atrioventricular valves close, creating the first sound (the lub) of a heartbeat. When the atrioventricular valves close, it keeps the blood from going back up into the atria. During this time, the aortic and pulmonary valves are open to allow blood into the aorta and pulmonary artery. When the ventricles finish contracting, the aortic and pulmonary valves close to prevent blood from flowing back into the ventricles. These valves closing is what creates the second sound (the dub) of a heartbeat.</li> <li>The second phase is called <strong>diastole</strong>&nbsp;(die-AS-tuh-lee). This is when the atrioventricular valves open and the ventricles relax. This allows the ventricles to fill with blood from the atria, and get ready for the next heartbeat.</li> </ol> <h3>How Can I Help Keep My Child's Heart Healthy?</h3> <p>To help keep your child's heart healthy:</p> <ul class="kh_longline_list"> <li>Encourage plenty of exercise.</li> <li>Offer a nutritious diet.</li> <li>Help your child reach and keep a <a href="https://kidshealth.org/ws/RadyChildrens/en/parents/childs-weight.html/">healthy weight</a>.</li> <li>Go for regular medical checkups.</li> <li>Tell the doctor about any family history of heart problems.</li> </ul> <p>Let the doctor know if your child has any chest pain, trouble breathing, or dizzy or <a href="https://kidshealth.org/ws/RadyChildrens/en/parents/fainting-sheet.html/">fainting</a> spells; or if your child feels like the heart sometimes goes really fast or skips a beat.</p>
Arrhythmia (Abnormal Heartbeat)An arrhythmia is an abnormal heartbeat usually caused by an electrical "short circuit" in the heart. Many are minor and not a health threat, but some can indicate a more serious problem.https://kidshealth.org/ws/RadyChildrens/en/parents/arrhythmias.html/19038a47-2ae4-48f8-8bd5-9e46150171b0
ArrhythmiasArrhythmias are abnormal heartbeats usually caused by an electrical "short circuit" in the heart. Many are minor and not a significant health threat, but others can indicate a more serious problem.https://kidshealth.org/ws/RadyChildrens/en/teens/arrhythmias.html/79184e00-417e-4ce4-a49b-2e89de1b1bd4
Atrial Septal DefectAtrial septal defect, or ASD, is a heart defect that some people are born with. Most ASDs are diagnosed and treated successfully with few or no complications.https://kidshealth.org/ws/RadyChildrens/en/teens/asd.html/109626e5-a3cb-4cba-a44d-947c86de3a81
Atrial Septal Defect (ASD)Atrial septal defect (ASD) — also known as a "hole in the heart" — is a type of congenital heart defect. Most ASDs are diagnosed and treated successfully.https://kidshealth.org/ws/RadyChildrens/en/parents/asd.html/2853e7be-1368-420f-bc8d-134350949604
Body Basics: The Heart (Slideshow)Learn how this amazing muscle pumps blood throughout the body.https://kidshealth.org/ws/RadyChildrens/en/parents/heart-slideshow.html/d0f34ce2-dbf0-4695-beb6-4fa3b7a09aec
Cardiac CatheterizationThis minimally invasive procedure helps doctors perform diagnostic tests on the heart and even treat some heart conditions.https://kidshealth.org/ws/RadyChildrens/en/parents/cardiac-catheter.html/e17d1f5d-ba99-46a6-865b-c426321a7d47
CardiomyopathyCardiomyopathy is when the heart muscle becomes weak and enlarged, which makes it difficult to pump blood through the body. There’s usually no cure for the condition in children, but it can be treated.https://kidshealth.org/ws/RadyChildrens/en/parents/cardiomyopathy.html/5b4f304e-1574-4ace-9820-6a44cbada41e
Congenital Heart DefectsHeart defects happen when there's a problem with a baby's heart development during pregnancy. Most heart defects can be treated during infancy.https://kidshealth.org/ws/RadyChildrens/en/parents/if-heart-defect.html/3dd23fa7-906f-4df9-8638-7400b77bed42
Heart DiseaseHeart disease, also called cardiovascular disease, mainly affects older people. Find out more in this article for kids.https://kidshealth.org/ws/RadyChildrens/en/kids/heart-disease.html/74747da9-ead7-47d6-9fe3-5d0eb8200a4d
Heart MurmursEveryone's heart makes sounds, but some people have hearts that make more noise than others. Usually, however, these heart murmurs don't mean anything is wrong. Find out more about these mysterious murmurs.https://kidshealth.org/ws/RadyChildrens/en/kids/heart-murmurs.html/38913fec-cf94-4522-b3c2-985ecb0f0db6
Heart and Circulatory SystemThe heart and circulatory system (also called the cardiovascular system) make up the network that delivers blood to the body's tissues.https://kidshealth.org/ws/RadyChildrens/en/teens/heart.html/fde8120a-c54e-4e57-94b8-fb4375c29487
Interrupted Aortic Arch (IAA)An interrupted aortic arch (IAA) is a rare heart condition in which the aorta doesn’t form completely. Surgery must be done within the first few days of a baby’s life to close the gap in the aorta. https://kidshealth.org/ws/RadyChildrens/en/parents/aortic-arch.html/d892fcbc-6205-4d08-83cb-903e58b78f39
Mitral Valve ProlapseMitral valve prolapse (MVP) is a very common heart condition, but it isn't a critical heart problem or a sign of other serious medical conditions.https://kidshealth.org/ws/RadyChildrens/en/parents/mvp.html/f0bfc3ea-10ec-4ec2-99d1-2ae174c2c999
Patent Ductus Arteriosus (PDA)The ductus arteriosus is a blood vessel that connects two major arteries before birth and normally closes after a baby is born. If it stays open, the result is a condition called patent ductus arteriosus (PDA).https://kidshealth.org/ws/RadyChildrens/en/parents/patent-ductus-arteriosus.html/1220a363-ed10-4541-94c6-ecb923902cd8
Patent Foramen Ovale (PFO)The foramen ovale is a normal opening between the upper two chambers of an unborn baby’s heart. It usually closes soon after the baby’s birth — when it doesn't, it's called a patent foramen ovale. https://kidshealth.org/ws/RadyChildrens/en/parents/pfo.html/27e4037d-e150-4b0f-a5b9-07375901eff3
Supraventricular Tachycardia (SVT)Supraventricular tachycardia is a type of abnormal heart rhythm in which the heart beats very quickly. https://kidshealth.org/ws/RadyChildrens/en/parents/supraventricular-tachycardia.html/fe5b0af6-4f7a-4fc8-a5f0-67c3f8fccceb
The HeartYour heart beats and sends oxygen throughout your entire body. Find out how it works and how heart problems can be fixed.https://kidshealth.org/ws/RadyChildrens/en/kids/center/heart-center.html/d4cb468c-ba42-454a-94bf-4173f8e15a69
Ventricular Septal DefectVentricular septal defect, or VSD, is a heart condition that a few teens can have. Find out what it is, how it happens, and what doctors do to correct it.https://kidshealth.org/ws/RadyChildrens/en/teens/vsd.html/840c44ec-78bd-4e55-ae74-37dcf68a1407
Words to Know (Heart Glossary)A guide to medical terms about the heart and circulatory system. In an easy A-Z format, find definitions on heart defects, heart conditions, treatments, and more.https://kidshealth.org/ws/RadyChildrens/en/parents/heart-glossary.html/ba52d6b8-f516-479b-b2de-ad634d6053da
Your Heart & Circulatory SystemYour heart is a hard-working muscle. Find out more in this article for kids.https://kidshealth.org/ws/RadyChildrens/en/kids/heart.html/9730472f-2ef1-413a-92bf-041c533b9564
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