Human Heart Structure and Function

Overview

This lecture explains the structure and function of the human heart, detailing the flow of blood through each chamber and associated vessels.

The heart functions as a powerful pump, circulating blood continuously from fetal development until death.
Its main job is to receive blood from the body and pump it back out.

Blood from the arms, head, and upper body returns to the heart via the superior vena cava.
Blood from the legs and lower body returns through the inferior vena cava.
All veins carry blood towards the heart.
Blood enters the right atrium and flows into the right ventricle through the tricuspid valve.
Blood passes through the pulmonary valve into the pulmonary arteries, which lead to the lungs.
In the lungs, blood releases carbon dioxide and picks up oxygen.
Oxygenated blood returns to the left atrium via the pulmonary veins.
Blood flows into the left ventricle through the mitral valve.
Blood is pumped out of the left ventricle through the aortic valve into the aorta, then to the body.
Arteries carry blood away from the heart.

The heart has four chambers: right atrium, right ventricle, left atrium, and left ventricle.
Valves (tricuspid, pulmonary, mitral, aortic) ensure one-way blood flow and prevent backflow.

Vein — vessel carrying blood towards the heart.
Artery — vessel carrying blood away from the heart.
Atrium — upper chamber of the heart that receives blood.
Ventricle — lower chamber that pumps blood out of the heart.
Tricuspid valve — valve between right atrium and right ventricle.
Pulmonary valve — valve between right ventricle and pulmonary artery.
Mitral valve — valve between left atrium and left ventricle.
Aortic valve — valve between left ventricle and aorta.
Pulmonary arteries — arteries carrying deoxygenated blood from the heart to the lungs.
Pulmonary veins — veins carrying oxygenated blood from the lungs to the heart.
Aorta — main artery distributing oxygenated blood to the body.