INTRODUCTION. The heart is a muscular pump that serves two functions: (1) to collect blood from the tissues of the body and pump it to the lungs and (2) to. The heart is a cone-shaped, muscular organ about the size of a fist. 4. The human heart contracts (beats) about 70 times a minute ( billion times in a. PDF | Molecular and genetic studies around the turn of this century While the primary heart tube is growing by addition of cells, it does not.

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of left ventricular twisting is the earliest sign of heart failure [26]. myocardial fibers in human embryo at 10 and 14 weeks, respectively;. In many ways, the human heart is a very simple The centerpiece of the exhibit is the giant walkthrough model of the human heart, described below. The Normal Heart and How It Works. The normal heart is a strong, hard-working pump made of muscle tissue. It's about the size of a person's fist. The heart has.

The cardiovascular system can be thought of as the transport system of the body.

This system has three main components: Blood can be thought of as a fluid which contains the oxygen and nutrients the body needs and carries the wastes which need to be removed. The following information describes the structure and function of the heart and the cardiovascular system as a whole. The heart is located in between the two lungs.

It lies left of the middle of the chest. The heart is a muscle about the size of a fist, and is roughly cone-shaped. It is about 12cm long, 9cm across the broadest point and about 6cm thick.

Human Heart: Anatomy, Function & Facts

The pericardium is a fibrous covering which wraps around the whole heart. It holds the heart in place but allows it to move as it beats. The wall of the heart itself is made up of a special type of muscle called cardiac muscle.

The heart has two sides, the right side and the left side.

The heart has four chambers. The left and right side each have two chambers, a top chamber and a bottom chamber. The two top chambers are known as the left and right atria singular: The atria receive blood from different sources.

The left atrium receives blood from the lungs and the right atrium receives blood from the rest of the body. The bottom two chambers are known as the left and right ventricles. The ventricles pump blood out to different parts of the body. The right ventricle pumps blood to the lungs while the left ventricle pumps out blood to the rest of the body. The ventricles have much thicker walls than the atria which allows them to perform more work by pumping out blood to the whole body.

Blood Vessel are tubes which carry blood.

Veins are blood vessels which carry blood from the body back to the heart. Arteries are blood vessels which carry blood from the heart to the body.

There are also microscopic blood vessels which connect arteries and veins together called capillaries. There are a few main blood vessels which connect to different chambers of the heart. The aorta is the largest artery in our body. The left ventricle pumps blood into the aorta which then carries it to the rest of the body through smaller arteries. The pulmonary trunk is the large artery which the right ventricle pumps into.

It splits into pulmonary arteries which take the blood to the lungs. The pulmonary veins take blood from the lungs to the left atrium. These two large veins then take the blood from the rest of the body into the right atrium.

Valves are fibrous flaps of tissue found between the heart chambers and in the blood vessels. They are rather like gates which prevent blood from flowing in the wrong direction. They are found in a number of places. Valves between the atria and ventricles are known as the right and left atrioventricular valves , otherwise known as the tricuspid and mitral valves respectively. Valves between the ventricles and the great arteries are known as the semilunar valves.

The aortic valve is found at the base of the aorta, while the pulmonary valve is found the base of the pulmonary trunk. There are also many valves found in veins throughout the body. However, there are no valves found in any of the other arteries besides the aorta and pulmonary trunk. The cardiovascular system refers to the heart, blood vessels and the blood.

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Blood contains oxygen and other nutrients which your body needs to survive. The body takes these essential nutrients from the blood. At the same time, the body dumps waste products like carbon dioxide, back into the blood, so they can be removed. The main function of the cardiovascular system is therefore to maintain blood flow to all parts of the body, to allow it to survive.

Veins deliver used blood from the body back to the heart. Blood in the veins is low in oxygen as it has been taken out by the body and high in carbon dioxide as the body has unloaded it back into the blood. All the veins drain into the superior and inferior vena cava which then drain into the right atrium. The right atrium pumps blood into the right ventricle. Then the right ventricle pumps blood to the pulmonary trunk, through the pulmonary arteries and into the lungs.

Human Heart: Anatomy, Function & Facts

In the lungs the blood picks up oxygen that we breathe in and gets rid of carbon dioxide, which we breathe out. The blood is becomes rich in oxygen which the body can use. From the lungs, blood drains into the left atrium and is then pumped into the left ventricle. The left ventricle then pumps this oxygen-rich blood out into the aorta which then distributes it to the rest of the body through other arteries.

The main arteries which branch off the aorta and take blood to specific parts of the body are:. The heart circulates blood through two pathways: In the pulmonary circuit, deoxygenated blood leaves the right ventricle of the heart via the pulmonary artery and travels to the lungs, then returns as oxygenated blood to the left atrium of the heart via the pulmonary vein.

In the systemic circuit, oxygenated blood leaves the body via the left ventricle to the aorta, and from there enters the arteries and capillaries where it supplies the body's tissues with oxygen. Deoxygenated blood returns via veins to the venae cavae, re-entering the heart's right atrium.

Of course, the heart is also a muscle, so it needs a fresh supply of oxygen and nutrients, too, Phillips said. The left main coronary artery, on one side of the aorta, branches into the left anterior descending artery and the left circumflex artery. The right coronary artery branches out on the right side of the aorta. A heart attack is distinct from cardiac arrest, which is a sudden loss of heart function that usually occurs as a result of electrical disturbances of the heart rhythm.

A heart attack can lead to cardiac arrest, but the latter can also be caused by other problems, he said.

Human heart anatomy

The heart contains electrical "pacemaker" cells, which cause it to contract — producing a heartbeat. In people with an irregular heartbeat, or atrial fibrillation, every cell tries to be the band leader, he said, which causes them to beat out of sync with one another. A healthy heart contraction happens in five stages.

In the first stage early diastole , the heart is relaxed.

Then the atrium contracts atrial systole to push blood into the ventricle. Next, the ventricles start contracting without changing volume. Then the ventricles continue contracting while empty.

Finally, the ventricles stop contracting and relax.

Then the cycle repeats. Valves prevent backflow, keeping the blood flowing in one direction through the heart. She received a graduate certificate in science communication from the University of California, Santa Cruz, and a bachelor of science in biomedical engineering from Brown University.The pulmonary valve is located at the base of the pulmonary artery.

It is about 12cm long, 9cm across the broadest point and about 6cm thick. The body takes these essential nutrients from the blood. Where blood passes near to the surface of the body, such as at the wrist or neck, it is possible to feel your pulse; this is the rush of blood as it is pumped through the body by the heart.

Blood contains oxygen and other nutrients which your body needs to survive. The atrioventricular valves are open. Atrial systole follows this phase.

The body is then able to use the oxygen in the blood to carry out its normal functions. Arteries are strong and stretchy, which helps push blood through the circulatory system. Two small openings above the aortic valve carry blood to the heart itself, the left main coronary artery and the right coronary artery.