The heart is an amazing organ. It pumps oxygen and nutrient-rich blood throughout your body to sustain life. This fist-sized powerhouse beats (expands and contracts) 100,000 times per day, pumping five or six quarts of
blood each minute, or about 2,000 gallons per day. Your heart is a key part of your cardiovascular system, which also includes all your blood vessels that carry blood from the heart to the body and then back to the heart. As the heart beats, it pumps blood through a system
of blood vessels, called the circulatory system. The vessels are elastic, muscular tubes that carry blood to every part of the body. Blood is essential. In addition to carrying fresh oxygen from the lungs and nutrients to the body's tissues, it also takes the body's waste products, including carbon dioxide, away from the tissues. This is necessary to sustain life and promote the
health of all parts of the body. There are three main types of blood vessels: This vast system of blood vessels -- arteries, veins, and capillaries -- is over 60,000 miles long. That's long enough to go around the world more than twice! The heart is located under the rib
cage, slightly to the left of your breastbone (sternum) and between your lungs. Looking at the outside of the heart, you can see that the heart is made of muscle. The strong muscular walls contract (squeeze), pumping blood to the rest of the body. On the surface of the heart, there are coronary arteries, which supply oxygen-rich blood to the heart muscle itself. The major blood vessels that enter the heart are the superior vena cava, the inferior vena cava, and the pulmonary veins. The
pulmonary artery exits the heart and carries oxygen-poor blood to the lungs. The aorta exits and carries oxygen-rich blood to the rest of the body. On the inside, the heart is a four-chambered, hollow organ. It is divided into the left and right side by a muscular wall called the septum. The right and left sides of the heart are further divided into two top chambers called the atria, which receive blood from the veins, and two bottom chambers called ventricles, which pump blood into
the arteries. The atria and ventricles work together, contracting and relaxing to pump blood out of the heart. As blood leaves each chamber of the heart, it passes through a valve. There are four heart valves within the heart: The tricuspid and mitral valves lie between the atria and ventricles. The aortic and pulmonic valves lie between the ventricles and
the major blood vessels leaving the heart. The heart valves work the same way as one-way valves in the plumbing of your home. They prevent blood from flowing in the wrong direction. Each valve has a set of flaps, called leaflets or cusps. The mitral valve has two leaflets; the others have three. The leaflets are attached to and supported by a ring of tough, fibrous tissue called the annulus. The annulus helps to maintain the proper shape of the valve. The leaflets of the mitral and tricuspid valves are also supported by tough, fibrous strings called chordae tendineae. These are similar to the strings supporting a parachute. They extend from the valve leaflets to small muscles, called papillary muscles, which are part of the inside walls of the ventricles. The right and left sides of the heart work together. The pattern described below
is repeated over and over, causing blood to flow continuously to the heart, lungs, and body. Once blood travels through the pulmonic valve, it enters your lungs. This is called the pulmonary circulation. From your pulmonic valve, blood travels to the pulmonary artery to tiny capillary vessels in the lungs. Here, oxygen travels from the tiny air sacs in the lungs, through the walls of the capillaries, into the blood. At the same time, carbon dioxide, a waste product of metabolism, passes from the blood into the air sacs. Carbon dioxide leaves the body when you exhale. Once the blood is oxygenated, it travels back to the left atrium through the pulmonary veins. What Are the Coronary Arteries of the Heart?Like all organs, your heart is made of tissue that requires a supply of oxygen and nutrients. Although its chambers are full of blood, the heart receives no nourishment from this blood. The heart receives its own supply of blood from a network of arteries, called the coronary arteries. Two major coronary arteries branch off from the aorta near the point where the aorta and the left ventricle meet: These arteries
and their branches supply all parts of the heart muscle with blood. Coronary artery disease occurs when plaque builds up in the coronary arteries and prevents the heart from getting the enriched blood it needs. If this happens, a network of tiny blood vessels in the heart that aren't usually open called collateral vessels may enlarge and become active. This
allows blood to flow around the blocked artery to the heart muscle, protecting the heart tissue from injury. How Does the Heart Beat?The atria and ventricles work together, alternately contracting and relaxing to pump blood through your heart. The electrical system of the heart is the power source that makes this possible. Your heartbeat is triggered by electrical impulses that travel down a special pathway through the heart.
At rest, a normal heart beats around 50 to 90 times a minute. Exercise, emotions, fever, and some medications can cause your heart to beat faster, sometimes to well over 100 beats per minute. How does the heart help other organ systems?It's the muscle at the centre of your circulation system, pumping blood around your body as your heart beats. This blood sends oxygen and nutrients to all parts of your body, and carries away unwanted carbon dioxide and waste products.
How many systems does the heart work with?The cardiovascular system consists of the heart, veins, arteries, and capillaries. These components make up two circulatory systems: the systemic and pulmonary circulatory systems.
How does the heart affect other body systems?Lungs and kidneys
If the heart is weak and cannot properly pump blood, fluid can begin building up in your lungs or kidneys. A lack of oxygen-rich blood in the kidneys disrupts the normal cycle of water and waste through the kidneys. This can cause swelling, or edema, in your ankles, feet and legs.
Which other body systems does the heart interact with?How does your heart work with other organs?. Nervous system: Your nervous system helps control your heart rate. It sends signals that tell your heart to beat slower during rest and faster during stress.. Endocrine system: Your endocrine system sends out hormones.. |