Every second or so, your heart beats. But do you know what’s happening when your heart makes this miraculous movement and sound? ProMedica HealthConnect asked a few of our ProMedica Physicians cardiologists and cardiothoracic surgeons to help us understand the heart and how it works.
A normal adult heart is the size of a clenched fist. “Think of the heart as a house with several rooms,” said Kamala Tamirisa, MD, FACC. It has four chambers, each with a one-way valve to make sure that the blood flows in only one direction.
The noise you hear when you listen to a heartbeat is its valves opening and closing. It’s the audible result of a sophisticated electrical system that controls all the actions that take place when your heart pumps blood. Because the blood flows in one direction, there’s a slight pumping delay between the upper and lower chambers.
Pumping: It’s Electric
According to Dr. Tamirisa, it all starts with the sinoatrial (SA) node, or dominate internal pacemaker. It generates an electric pulse that kicks off the cycle that tells the heart to contract. “The SA node sends signals to another pacemaker called the atrioventricular node, located on the septum [the wall of tissue that divides the heart into left and right sides]. From there, electrical wires extend throughout the heart.”
“Basically, the heart is a complex pump and its job is to pump blood throughout your body,” says Adil Karamali, MD, FACC, cardiologist. “The arterial system (arteries) carries oxygen-rich blood to the body from head to toe. As the various organs and tissues use up the oxygen, the blood returns to the heart through the venous system (veins).”
“The blood vessels of the arterial system are much more muscular and the walls are thicker,” says Dr. Tamirisa, MD, FACC. “The blood vessels of the venous system are not as muscular or thick and the walls are very collapsible.”
When your heart pumps blood through your arteries, it creates a pulse. You can feel this pulse on the arteries that are close to the skin’s surface. Usually, you can feel your pulse on your neck just right or left of your wind pipe or on the inside of either wrist below your thumb.
Feeding the Body, Feeding the Heart
Like every other part of your body, the heart needs blood too. That’s why some blood vessels are connected directly to the heart.
“The heart gets its blood through the coronary arteries,” says William Rachwal, MD, FACS, cardiothoracic surgeon. “The left and right coronary arteries are connected to the aorta, the main artery.” After the left ventricle of the heart pumps blood through the aortic valve into the aorta, the valve closes and blood flows into the coronary arteries to supply the heart with blood.
The heart is a complex muscle that is the center of an intricate circulatory system. With each beat, it’s delivering your body with the right amount of blood to keep it functioning properly.