Ventricle (heart)

Your heart has two big parts.

These parts are called ventricles. They sit at the bottom of your heart.

One part sends blood to your lungs. This part has thinner walls. The other part sends blood to your whole body.

This part has thicker walls.

These walls must be strong. They push blood with a lot of force. This helps the blood move everywhere.

The heart works in a cycle. It squeezes to push blood out. Then it relaxes to fill with blood again.

Your heart does this all day. It keeps your blood moving well.

The heart has two large chambers at the bottom. We call these chambers ventricles.

Above them are smaller parts called atria. The atria fill the ventricles with blood first. Then, the ventricles squeeze to push the blood out.

There are two different ventricles. The right ventricle pumps blood to the lungs. The left ventricle pumps blood to the whole body.

Because it works harder, the left ventricle has thicker walls. It must push blood at a high pressure. The right ventricle is smaller and has thinner walls.

Inside, the ventricles have bumpy muscle parts. We call these trabeculae carneae. They cover the inner walls. The ventricles also work in a cycle. During systole, the muscles contract to pump blood. During diastole, they relax to fill up again. A healthy adult heart pumps about 5 liters of blood every minute while resting. This keeps your body moving well.

The heart is a busy pump that keeps us alive. At the bottom of the heart are two large chambers called ventricles.

These chambers have a very important job. They collect blood and then push it out to the rest of the body. Before the blood reaches the ventricles, it must pass through smaller chambers called atria. The atria sit just above the ventricles in the upper part of the heart. This setup allows the heart to move blood in a steady, repeating cycle.

The way the ventricles work follows two main steps. First, there is a phase called diastole. During diastole, the ventricles relax so they can fill up with blood. Next comes the phase called systole. During systole, the thick muscles of the ventricles contract or squeeze. This squeeze pushes the blood out through special valves. The left ventricle pushes blood through the aorta to the whole body. The right ventricle pushes blood into the pulmonary artery to reach the lungs.

Doctors use many tools to study how these chambers work. They can use magnetic resonance imaging to find the mass of the left ventricle. On average, the mass of this chamber is about 143 grams. The right ventricle is about the same size and holds roughly 85 milliliters of blood.

Scientists also measure the distance across the chambers in millimeters. They look at the dimension at the end of diastole and the end of systole. These numbers help them see if the heart is pumping well.

There are many specific parts inside the ventricles. The walls are not smooth like a balloon. Instead, they have bumpy muscle columns called trabeculae carneae.

There are also tiny muscles called papillary muscles. These muscles connect to strings called chordae tendinae. These strings help control the valves that keep blood moving in the right direction. In the right ventricle, there is also a part called the conus arteriosus. This area helps the blood flow into the pulmonary artery.

You can think of the ventricles like the heavy-duty engines of a car. The left ventricle is the strongest engine because it has the hardest job. It must push blood at a high pressure of about 120 mmHg. The right ventricle only has to push blood to the nearby lungs. Because of this, the left ventricle has walls that are much thicker. By the time someone is an adult, the left wall can be three to six times thicker than the right.

This strength ensures that every part of your body gets the blood it needs.

The ventricles are two large chambers located at the bottom of the heart. They serve as the primary pumps of the cardiovascular system. Their main job is to collect blood from the atria and expel it toward the lungs or the rest of the body. Because they must move blood against significant resistance, ventricles have much thicker walls than the atria. In a human heart, these two chambers work together within a double circulatory system. This system ensures that oxygen-rich blood and oxygen-poor blood stay separate as they move through the body.

The function of the ventricles occurs in a repeating two-step cycle. The first phase is called diastole, which is the period when the ventricles relax. During diastole, the chambers expand to fill with blood flowing from the adjacent atria. The second phase is called systole, the period of contraction. During systole, the ventricular muscles squeeze forcefully to pump the blood out. The left ventricle receives oxygenated blood from the left atrium via the mitral valve. It then pumps this blood through the aortic valve into the aorta. Simultaneously, the right ventricle receives deoxygenated blood from the right atrium via the tricuspid valve. It pushes this blood through the pulmonary valve into the pulmonary artery to reach the lungs.

The two ventricles have distinct structures and roles. The left ventricle is longer and more conical in shape. It has much thicker, more muscular walls because it must generate high pressure. It pushes blood into the systemic circulation at a typical pressure of about 120 mmHg. In contrast, the right ventricle is triangular in shape. When viewed in a cross section, it appears crescent-shaped. It only needs to pump blood to the lungs, so it operates at a lower pressure. The right ventricle is composed of two parts called the sinus and the conus. The sinus acts as the inflow area for blood coming from the tricuspid valve. The conus arteriosus is a conical pouch from which the pulmonary artery arises.

Inside the ventricles, the muscular structure is quite complex. The inner walls are not smooth but are covered in irregular muscular columns called trabeculae carneae. These columns cover most of the inner surfaces. Within these walls, there are specific types of muscles. One type is the papillary muscles. These muscles attach to strings called chordae tendinae. These strings, in turn, connect to the cusps of the tricuspid and mitral valves. This mechanism helps regulate the valves during the heartbeat. In the right ventricle, three specific muscle bands separate the chamber: the parietal, the septal, and the moderator band. The moderator band specifically connects the base of the anterior papillary muscle to the ventricular septum.

Physicians use several measurements to understand how well the ventricles are performing. They often look at the mass and the volume of the chambers. Using magnetic resonance imaging, researchers have estimated the average mass of the left ventricle at 143 g, with a range between 87 g and 224 g. The right ventricle is roughly equal in size and holds about 85 milliliters of blood in an adult. Doctors also measure dimensions in millimeters, such as the end-diastolic dimension (EDD) and the end-systolic dimension (ESD). These measurements help determine the end-diastolic volume (EDV) and the end-systolic volume (ESV). Another important metric is the ejection fraction (Ef), which helps assess pumping efficiency.

The workload of the ventricles changes significantly as a person develops. By young adulthood, the walls of the left ventricle have thickened considerably. They can become three to six times thicker than the walls of the right ventricle. This thickening is a response to the pressure workload. The left ventricle must accept blood at roughly 80 mmHg and push it forward to about 120 mmHg. This pressure is necessary to stretch the aorta and other arteries. A healthy adult heart typically pumps about 5 liters of blood per minute at rest. However, this capacity can increase greatly. For non-athletes, the maximum pumping volume may reach 25 liters per minute. For Olympic-level athletes, it can reach as high as 45 liters per minute.

Sometimes, the electrical system of the ventricles does not function normally. This can lead to an arrhythmia, which is an irregular heartbeat. While the heartbeat usually starts in the atrium, it can sometimes begin in the Purkinje fibres of the ventricles. This can cause premature ventricular contractions, also known as ventricular extra beats. If these beats occur in groups, the condition is called ventricular tachycardia. In some cases, the ventricles may produce a ventricular escape beat as a compensatory mechanism. The most severe type of arrhythmia is ventricular fibrillation. This condition is a common cause of cardiac arrest and sudden death.