The left ventricle is the most important part of the heart for a few key reasons:

1. Pumping Oxygenated Blood:

   • The left ventricle sends oxygen-rich blood into the aorta.
   • This blood then travels all around the body.
   • Each time it contracts, it pushes out about 70 mL of blood, which helps keep everything working well.

2. Creating High Pressure:

   • The left ventricle builds up a lot of pressure, around 120 mmHg.
   • This high pressure is necessary to push blood through the body’s organs.
   • In comparison, the right ventricle only creates about 25 mmHg because it just sends blood to the lungs.

3. Thick Muscles:

   • The wall of the left ventricle is about 1.5 cm thick.
   • This thickness helps it create the high pressure needed to pump blood throughout the body.
   • The right ventricle's wall is only 0.5 cm thick, which is not enough for this task.

4. Size of the Chamber:

   • The left ventricle takes up about 20% of the heart's space.
   • This shows how important it is for making the heart work properly.

5. Ejection Fraction:

   • A healthy left ventricle usually pumps out 55% to 70% of the blood it holds with each beat.
   • This number, known as the ejection fraction, helps show how well the heart is working.

In short, the left ventricle is vital because it pumps blood to the whole body, generates high pressure, has thick muscles, takes up a good amount of space in the heart, and efficiently pushes out blood. All these factors show its critical role in keeping our bodies healthy.