Heart Diagram: Structure, Valves, and Blood Circulation

The human heart is a vital organ that keeps us alive by pumping blood throughout the body. It works tirelessly to deliver oxygen and nutrients to every cell while carrying away waste products. In this article, we will explore the diagram of the heart, its structure, the heart diagram with labelling, the section of the human heart diagram, and a simple flow chart of heart function. This content is presented in a way that will help students of all levels understand the topic easily.

Structure of the Human Heart

The heart has four chambers:

1. Upper Chambers (Atria): These include the right atrium and left atrium (also called auricles). They receive blood returning to the heart.

2. Lower Chambers (Ventricles): These include the right ventricle and left ventricle. They pump blood out of the heart to the lungs or the rest of the body.

Major Blood Vessels

• Arteries: Transport oxygenated blood from the heart to various body areas. However, the pulmonary artery is unique; it carries oxygen-poor blood to the lungs.

• Veins: Transport blood low in oxygen from the body back to the heart. The pulmonary vein is an exception, carrying oxygen-rich blood from the lungs to the heart.

Layers of the Heart Wall

The heart wall has three layers:

1. Epicardium (outer layer)

2. Myocardium (middle layer): This muscular layer is responsible for the heart’s contractions.

3. Endocardium (inner layer)

Valves of the Heart

The heart contains four valves to prevent backflow of blood:

1. Aortic Valve: Stops blood from flowing back into the left ventricle from the aorta.

2. Mitral Valve: Prevents blood returning to the left atrium when the left ventricle contracts.

3. Pulmonary Valve: Stops blood from flowing back into the right ventricle from the pulmonary artery.

4. Tricuspid Valve: Prevents blood returning to the right atrium when the right ventricle contracts.

Blood Flow Chart of the Heart

Below is a simple flow chart of heart circulation:

1. Blood lacking oxygen enters the right atrium from the body through the vena cava.

2. It then moves into the right ventricle through the tricuspid valve.

3. The right ventricle pushes this blood to the lungs via the pulmonary artery, where it gets oxygen.

4. Oxygenated blood travels back to the left atrium from the lungs through the pulmonary vein.

5. It then passes through the mitral valve into the left ventricle.

6. The left ventricle pumps this oxygen-rich blood into the aorta, distributing it throughout the body.

Human Heart Diagram (Labelled)

When looking at a human heart diagram, you will notice clear divisions of the atria and ventricles, along with the valves positioned at the boundaries of these chambers. Each component works together to ensure continuous blood circulation.

Quick Quiz

1. Which blood vessel carries oxygenated blood from the lungs to the heart?
Answer: Pulmonary vein

2. Name the valve that prevents backflow of blood into the left ventricle.
Answer: Aortic valve

3. What is the middle layer of the heart wall called?
Answer: Myocardium

4. How many chambers are there in the human heart?
Answer: Four (two atria and two ventricles)

5. Which side of the heart handles deoxygenated blood?
Answer: Right side (right atrium and right ventricle)

Heart Attack Warning Signs

Common warning signs include:

• Pain in the chest or discomfort

• Shortness of breath

• Nausea or vomiting

• Excessive sweating

Paying attention to these signs and seeking medical help early can save lives.

Related Topics

• Human Heart

• Circulatory System

• Heart Diseases

• Difference Between Arteries and Veins