How does blood flow through the heart?

Question

The heart provides your body access to an incredible amount of oxygen every second, but how does it do it?

Answer 1

Blood flows through the heart through a series of chambers, valves, and blood vessels. Deoxygenated blood first enters the right atrium from the superior vena cava, inferior vena cava, and coronary sinus. From there, blood flows through the tricuspid valve into the right ventricle. When the heart contracts, the deoxygenated blood in the right ventricle is pumped upward through the semilunar pulmonary valve into the pulmonary trunk, then laterally through the pulmonary arteries and into the lungs.

In the lungs, blood flows through pulmonary capillaries surrounding the alveoli, where oxygen diffuses across simple squamous epithelial tissue and binds to hemoglobin. At this point, the blood is considered oxygenated. The oxygenated blood then returns to the heart through the pulmonary veins and enters the left atrium. From there, blood flows through the bicuspid (mitral) valve into the left ventricle, which contains the thickest wall of myocardium, or heart muscle. The increased musculature of the left ventricle allows it to generate enough force to pump oxygenated blood throughout the systemic circulation.

When the left ventricle contracts, blood is pumped upward through the semilunar aortic valve into the aorta. Blood then travels superiorly through the three major branches of the aortic arch. From anatomical right to left, these branches are the brachiocephalic trunk, left common carotid artery, and left subclavian artery. Blood is also carried inferiorly through the descending and abdominal aorta to supply the lower portions of the body.

Remember, the names “arteries” and “veins” refer to the direction of blood flow relative to the heart. Arteries carry blood away from the heart, while veins carry blood toward the heart.

Answer 2

Great question my friend!

The heart has four chambers --> right atrium, right ventricle, left atrium, and left ventricle. Right sided chambers deal with deoxygenated/venous blood, while the left sided chambers deal with oxygenated/arterial blood.

1. Blood first flows into the right atrium from the superior vena cava (drains head, arms, and upper torso) and inferior vena cava (drains lower body).
2. Blood then moves from right atrium to right ventricle through the tricuspid valve, which separates both chambers.
3. The right ventricle then pumps that blood through the pulmonary artery, which delivers deoxygenated blood the lungs, where it's readily oxygenated.
4. The now oxygenated blood travels through the pulmonary veins and delivers oxygen rich blood to the left atrium.
5. Blood then moves from the left atrium to the left ventricle through the mitral valve, which separates both chambers.
6. The left ventricle, the strongest and most muscular chamber of the heart, pumps oxygen rich blood to the whole body through the aorta, the largest artery in the body.

Always down to chat more about the heart! Let me know how else I can help.

Answer 3