It is good to understand what the human heart looks like and how it functions. That makes it easier to take care of it and realize when it needs attention.
Every part of the body uses and releases substances the blood carries:
- Gasses, such as oxygen and carbon dioxide
- Minerals, such as sodium and potassium
- Fats, such as cholesterol and triglycerides
- Sugar, which is glucose
and other substances. Some things blood-transports are nutrients and some are waste products. Nutrients include glucose and waste products include carbon dioxide.
Let’s look closer at the human heart.
The upside-down pear-shaped pumping muscle typically weighs more than half a pound (about 9-12 ounces, 250-350 grams).
In an adult, this vital organ can be 5 inches (12 centimeters) tall, 3½ inches (8 centimeters) wide, and 2 ½ inches (6 centimeters) deep. Some people compare its size and shape to a clenched fist. Generally, women’s and children’s hearts are smaller than men’s hearts.
Next, let’s follow the path of blood moving through the heart. The heart anatomy diagram on the left displays color-coded parts. Blue parts move blood carrying carbon dioxide—a waste product, and red parts move blood carrying oxygen—an essential gas.
In the “blue” path, blood carries carbon dioxide from the body:
- Blood enters through the superior vena cava and inferior vena cava and travels through the right atrium and tricuspid valve to the right ventricle.
- Then it travels through the pulmonary valve and pulmonary artery to the lungs, where it releases carbon dioxide and takes on oxygen.
In the “red” path, blood carries oxygen from the lungs:
- Blood enters through the pulmonary veins and travels through the left atrium and mitral valve to the left ventricle.
- Then it travels through the aortic valve and aorta to the body, where it releases oxygen and takes on carbon dioxide.
A series of specific coordinated muscle contractions keep the heart pumping blood every moment we live. The heart’s electrical signals time these contractions to keep blood moving in the right direction.
This amazing process keeps us living and doing. Please share what you think about the life-sustaining job of the heart.