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- In humans and other mammals and in birds, the heart is a four-chambered double pump that is the centre of the circulatory system. In humans it is situated between the two lungs and slightly to the left of centre, behind the breastbone; it rests on the diaphragm, the muscular partition between the chest and the abdominal cavity.
Nov 10, 2024 · The heart is a muscular organ that pumps blood throughout the body via the circulatory system. It is approximately the size of a fist and consists of four chambers: two atria and two ventricles. The heart is composed of specialized muscle tissue, known as myocardium , and is encased within a double-layered protective sac called the pericardium .
Oct 31, 2024 · Passage of blood through the left atrium, bicuspid valve, left ventricle, aorta, tissues of the body, and back to the right atrium constitutes the systemic circulation. Blood pressure is greatest in the left ventricle and in the aorta and its arterial branches.
- The Editors of Encyclopaedia Britannica
- In humans, the heart is situated between the two lungs and slightly to the left of center, behind the breastbone. It rests on the diaphragm, the mu...
- The heart consists of several layers of a tough muscular wall, the myocardium. A thin layer of tissue, the pericardium, covers the outside, and ano...
- The pumping of the heart, or the heartbeat, is caused by alternating contractions and relaxations of the myocardium. These contractions are stimula...
- The rhythmic noises accompanying the heartbeat are called heart sounds. The two distinct sounds are heard, a low, slightly prolonged “lub” (first s...
May 10, 2023 · The heart is located underneath the sternum in a thoracic compartment called the mediastinum, which occupies the space between the lungs. The location of the heart. 1. 2. 3. The heart is approximately the size of a an adult’s fist and it weights 230-350 grams. It is shaped like an inverted cone.
- Overview
- How does the heart work?
- Heart anatomy
- How do you know if the heart is healthy?
- Symptoms of a heart attack
- Other heart conditions
- When to see a doctor
- Summary
The heart is a complex organ that pumps blood throughout the body. It sits in the chest, slightly left of center, behind the breastbone, and between the lungs.
A heart that is not healthy does not always produce symptoms. However, certain signs and symptoms can indicate a problem with the heart.
The heart is responsible for pumping blood throughout the body. To do this, the heart fills with blood and then contracts to push the blood through the circulatory system. Electrical impulses tell the heart how often to contract or “beat.”
The right side of the heart receives blood from the veins and pumps it on toward the lungs. Here, the blood receives oxygen and removes carbon dioxide for the lungs to breathe out. The left side of the heart then receives the oxygenated blood from the lungs and pumps it through arteries to the rest of the body.
The interactive BodyMap diagram below shows the location of the heart in the chest. Press the buttons to interact, including adding and removing layers and moving around the diagram.
The heart has four distinct chambers. The left and right atria are at the top, and the left and right ventricles are at the bottom. The septum is a tissue wall separating the left and right chambers.
The heart also has four valves:
•The pulmonic valve opens and closes to regulate blood flow from the right ventricle to the pulmonary artery (lungs).
•The aortic valve opens and closes to regulate oxygenated blood from the left ventricle to the aorta (the largest artery in the body).
•The mitral valve opens and closes to regulate oxygenated blood flow from the left atrium to the left ventricle.
Signs of arrhythmia
Heart arrhythmia is the medical term for a heartbeat that is too fast, too slow, or irregular. Arrhythmias occur when the electrical impulses that control the heartbeat malfunction. This can give rise to a fluttering sensation in the chest, which doctors refer to as palpitations. A persistent arrhythmia can affect heart function, leading to more severe symptoms, such as: •pounding sensations in the chest •weakness or fatigue •dizziness or lightheadedness •fainting •shortness of breath •anxiety •pain or pressure in the chest •sudden cardiac arrest •swelling in the feet, legs, hands or other areas of the body Palpitations are not always a sign of an underlying heart condition. They can occur as a result of anxiety or the use of caffeine and other stimulants. However, a person should see a doctor if they experience frequent arrhythmias, or they experience other signs and symptoms of a heart problem.
Signs of heart failure
Heart failure is where the heart is no longer effective at pumping blood around the body. According to the American Heart Association (AHA), some common signs of heart failure include: •an unexplained increase in heart rate •tiredness or fatigue •confusion or inability to think clearly •nausea •loss of appetite •swelling in the feet, legs, hands or other areas of the body with unexplained weight gain •shortness of breath •sleeping on extra pillows •waking up at night short of breath •a persistent cough that may produce pink-tinged mucus
A heart attack is a medical emergency in which the blood supply to the heart becomes blocked. Without sufficient blood supply, the heart muscles become damaged and begin to die.
According to the Centers for Disease Control and Prevention (CDC), the five most common signs of a heart attack include:
•chest pain or discomfort
•pain or discomfort in one or both shoulders or arms
•discomfort or pain in the jaw, back or neck
•shortness of breath
Heart disease is an umbrella term that can refer to several different heart conditions. The most common is coronary artery disease (CAD). In CAD, the major arteries that supply the heart become blocked or damaged, thereby increasing the risk of a heart attack.
Other conditions related to heart disease include:
•Angina: Pain in the chest due to lack of blood to the heart.
•Aortic aneurysm and dissection: A condition in which the aorta becomes enlarged or torn.
•Arrhythmias: A heartbeat that is irregular or abnormally fast or slow.
•Atherosclerosis: A buildup of fatty deposits, or plaque, in the arteries.
A person should talk to their doctor if they experience signs or symptoms of the following conditions:
•heart arrhythmia
•heart disease
•any underlying medical condition that could affect the heart
The heart is a complex organ with several chambers, valves, and tissues that work together to pump blood around the body. Electrical impulses regulate the timing of each heartbeat.
Sometimes, heart disease is silent, meaning a person may not develop any symptoms until they experience a cardiac event, such as arrhythmia or heart attack. People must see a doctor if they experience any concerns relating to their heart.
- The Heart Wall Is Composed of Three Layers. The muscular wall of the heart has three layers. The outermost layer is the epicardium (or visceral pericardium).
- The Atria Are the Heart’s Entryways for Blood. The left atrium and right atrium are the two upper chambers of the heart. The left atrium receives oxygenated blood from the lungs.
- Each Heart Beat Is a Squeeze of Two Chambers Called Ventricles. The ventricles are the two lower chambers of the heart. Blood empties into each ventricle from the atrium above, and then shoots out to where it needs to go.
- The Valves Are Like Doors to the Chambers of the Heart. Four valves regulate and support the flow of blood through and out of the heart. The blood can only flow one way—like a car that must always be kept in drive.
In humans, the heart is approximately the size of a closed fist and is located between the lungs, in the middle compartment of the chest, called the mediastinum. [4]
Jun 11, 2024 · The heart is the pump that moves blood around your body. It has four main parts: two upper chambers called atria and two lower chambers called ventricles. These parts work together to get oxygen-rich blood to your body and oxygen-poor blood back to your heart.
