Heart: Anatomy and Function (2023)

FAQs

What is the anatomy and function of the heart? ›

The heart is a fist-sized organ that pumps blood throughout your body. It's the primary organ of your circulatory system. Your heart contains four main sections (chambers) made of muscle and powered by electrical impulses. Your brain and nervous system direct your heart's function.

As the central part of the circulatory system, the heart is responsible for pumping blood, supplying oxygen and nutrients, and removing metabolic waste such as carbon dioxide from all the tissues in the body.

The heart is made up of four chambers. The upper two chambers are called atria (singular: atrium) and the lower two are known as ventricles (singular: ventricle). Muscular walls, called septa or septum, divide the heart into two sides.

Two of the valves, the mitral and the tricuspid valves, move blood from the upper chambers of the heart (the atria) to the lower chambers of the heart (the ventricles). The other two valves, the aortic and pulmonary valves, move blood to the lungs and the rest of the body through the ventricles.

It's the muscle at the centre of your circulation system, pumping blood around your body as your heart beats. This blood sends oxygen and nutrients to all parts of your body, and carries away unwanted carbon dioxide and waste products.

Blood flows through the heart in the following order: 1) body –> 2) inferior/superior vena cava –> 3) right atrium –> 4) tricuspid valve –> 5) right ventricle –> 6) pulmonary arteries –> 7) lu ngs –> 8) pulmonary veins –> 9) left atrium –> 10) mitral or bicuspid valve –> 11) left ventricle –> 12) aortic valve –> 13) ...

The heart is a pump, usually beating about 60 to 100 times per minute. With each heartbeat, the heart sends blood 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 lungs to pick up more oxygen.

The right ventricle pumps the low-oxygen blood to the lungs to pick up a fresh supply of oxygen. The left atrium receives to high-oxygen blood from the lungs and pumps it to the left ventricle. The left ventricle pumps the high-oxygen blood to the rest of the body.

The 2 main coronary arteries are the left main and right coronary arteries.

Blood comes into the right atrium from the body, moves into the right ventricle and is pushed into the pulmonary arteries in the lungs. After picking up oxygen, the blood travels back to the heart through the pulmonary veins into the left atrium, to the left ventricle and out to the body's tissues through the aorta.

What color is the heart without blood? ›

The heart will appear white if it has been drained of blood.

The aorta is the largest blood vessel in your body. It's more than 1 foot long and an inch in diameter at its widest point.

The wall of the heart separates into the following layers: epicardium, myocardium, and endocardium. These three layers of the heart are embryologically equivalent to the three layers of blood vessels: tunica adventitia, tunica media, and tunica intima, respectively.

The network of nerves supplying the heart is called the cardiac plexus. It receives contributions from the right and left vagus nerves, as well as contributions from the sympathetic trunk. These are responsible for influencing heart rate, cardiac output, and contraction forces of the heart.

A typical heart has two upper and two lower chambers. The upper chambers, the right and left atria, receive incoming blood. The lower chambers, the more muscular right and left ventricles, pump blood out of the heart.

ventricles (VEN-trih-kuhls): The two chambers at the bottom of the heart are called the ventricles. The heart has a left ventricle and a right ventricle.

The largest artery is the aorta, the main high-pressure pipeline connected to the heart's left ventricle. The aorta branches into a network of smaller arteries that extend throughout the body.

Aortic valve: This valve has three leaflets. They open to let blood flow from your heart's left ventricle to the aorta. The aorta is the largest blood vessel in your body. It brings oxygenated blood from your heart to the rest of your body.

The tricuspid valve sits between the heart's two right chambers. The tricuspid valve consists of three thin flaps of tissue (called cusps, or leaflets). These valve flaps open to let blood flow from the upper right chamber (right atrium) to the lower right chamber (right ventricle).

The left ventricle is the strongest because it has to pump blood out to the entire body. When your heart functions normally, all four chambers work together in a continuous and coordinated effort to keep oxygen-rich blood circulating throughout your body.

What is the single most important key to heart health? ›

However, when it really comes down to it, the most important steps that anyone can take to help prevent heart disease fall into one of two main categories: Remaining physically active and maintain a healthy weight.

The heart is a hollow muscular organ about the size of a closed fist. It's in the centre of your chest, behind the breastbone. Each heartbeat sends blood that's rich in oxygen and nutrients to all parts of your body.

Of note, there are other mnemonics, such as “Try Pulling My Aorta” where T stands for tricuspid, P stands for pulmonary, M stands for Mitral, and A stands for aortic, that can assist in remembering the the anatomical positions of the heart valves and the order in which blood flows through the heart.

A network of arteries and veins also carry blood throughout the body: Arteries transport blood from the heart to the body tissues. Veins carry blood back to the heart.

A normal heart and heart valve problems

The four heart valves, which keep blood flowing in the right direction, are the mitral, tricuspid, pulmonary and aortic valves. Each valve has flaps (leaflets) that open and close once per heartbeat.

The heart is made up of four chambers: two upper chambers known as the left atrium and right atrium and two lower chambers called the left and right ventricles. It is also made up of four valves: the tricuspid, pulmonary, mitral and aortic valves.

Heart rate is controlled by the two branches of the autonomic (involuntary) nervous system. The sympathetic nervous system (SNS) and the parasympathetic nervous system (PNS). The sympathetic nervous system (SNS) releases the hormones (catecholamines - epinephrine and norepinephrine) to accelerate the heart rate.

The heart's blood pumping cycle, which is called the cardiac cycle, begins when oxygen-free blood returns to the heart through the right atrium, after distributing oxygen and nutrients to other parts of the body. The blood then moves into the right ventricle, which facilitates a transfer of blood into the lungs.

Although blockages can occur in other arteries leading to the heart, the LAD artery is where most blockages occur.

The LAD artery is the most commonly occluded of the coronary arteries.

What is heart blockage called? ›

This condition is called atherosclerosis. The buildup is called plaque. Plaque can cause the arteries to narrow, blocking blood flow. The plaque can also burst, leading to a blood clot.

Arteries and veins go into and out of the heart. Arteries carry blood away from the heart and veins carry blood to the heart. The flow of blood through the vessels and chambers of the heart is controlled by valves.

Heart sounds are created from blood flowing through the heart chambers as the cardiac valves open and close during the cardiac cycle. Vibrations of these structures from the blood flow create audible sounds — the more turbulent the blood flow, the more vibrations that get created.

It's time we start seeing red. Red — as in the color of heart disease awareness, just as pink is the color we all take notice of in regard to breast cancer.

The hardest working muscle is the heart. It pumps out 2 ounces (71 grams) of blood at every heartbeat. Daily the heart pumps at least 2,500 gallons (9,450 liters) of blood. The heart has the ability to beat over 3 billion times in a person's life.

The human heart beats approximately 70 to 85 times per minute in an average adult, with a notable difference between the genders. The average adult male heart rate is between 70 and 72 beats per minute, while the average for adult women is between 78 and 82 beats.

The pulmonary vein carries oxygen around the body back to the heart. It, therefore, has the greatest oxygen content. The primary pulmonary artery, also known as the pulmonary trunk, is a blood vessel that leaves the heart.

Capillaries. Capillaries, the smallest and most numerous of the blood vessels, form the connection between the vessels that carry blood away from the heart (arteries) and the vessels that return blood to the heart (veins).

The vena cava has two parts: the superior vena cava and the inferior vena cava. The superior vena cava carries blood from the head, neck, arms, and chest. The inferior vena cava carries blood from the legs, feet, and organs in the abdomen and pelvis. The vena cava is the largest vein in the body.

The muscle layer of the heart is termed the myocardium and is made up of cardiomyocytes. The myocardium is found in the walls of all four chambers of the heart, though it is thicker in the ventricles and thinner in the atria.

What tissue is the heart made of? ›

The human body contains three different kinds of muscle tissue: skeletal, smooth, and cardiac. Only cardiac muscle tissue, comprising cells called myocytes, is present in the heart.

The myocardium is the middle and thickest layer of the heart wall. (Myo- means "muscle.") Most of the heart wall is the myocardium. It also houses the cardiac electroconductive system (SA node, AV node, HIS fibers, and Purkinje fibers). PERICARDIUM: makes up the outer layers of the heart wall, enclosing the heart.

The two main functions of the heart are to pump deoxygenated blood to the lungs in order to receive oxygen, and then to pump oxygenated blood out to all body parts. The circulatory system works to pump blood all throughout the body, carrying with it important molecules such as oxygen and nutrients.

A normal heart pumps blood out of its left ventricle at about 50 to 70 percent — a measurement called an ejection fraction, according to the American Heart Association. “Don was at 10 percent, which is basically a nonfunctional heart,” Dow said. “When a heart is pumping at only 10 percent, a person can die very easily.

The heart is a hollow muscular organ about the size of a closed fist. It's in the centre of your chest, behind the breastbone. Each heartbeat sends blood that's rich in oxygen and nutrients to all parts of your body.

The heart is made up of four chambers: two upper chambers known as the left atrium and right atrium and two lower chambers called the left and right ventricles. It is also made up of four valves: the tricuspid, pulmonary, mitral and aortic valves.

Blood comes into the right atrium from the body, moves into the right ventricle and is pushed into the pulmonary arteries in the lungs. After picking up oxygen, the blood travels back to the heart through the pulmonary veins into the left atrium, to the left ventricle and out to the body's tissues through the aorta.

40 to 55% – Below normal heart function. Can indicate previous heart damage from heart attack or cardiomyopathy. Higher than 75% – Can indicate a heart condition like hypertrophic cardiomyopathy, a common cause of sudden cardiac arrest. Less than 40% – May confirm the diagnosis of heart failure.

A score of 120/80 is optimal, and 140/90 is normal for most people. Higher readings mean that arteries aren't responding right to the force of blood pushing against artery walls (blood pressure), directly raising the risk of heart attack or stroke.