what vena cava carries blood from the head and arms to the heart

How Your Heart Works

Learn How the Heart Works

Your centre is an amazing organ. It continuously pumps oxygen and nutrient-rich blood throughout your torso to sustain life. This fist-sized powerhouse beats (expands and contracts) 100,000 times per day, pumping five or six quarts of claret each minute, or about ii,000 gallons per day.

How Does Blood Travel Through the Center?

As the middle beats, information technology pumps blood through a arrangement of claret vessels, called the circulatory organisation. The vessels are elastic, muscular tubes that comport blood to every part of the torso.

Claret is essential. In improver to carrying fresh oxygen from the lungs and nutrients to your body's tissues, it also takes the body's waste product products, including carbon dioxide, away from the tissues. This is necessary to sustain life and promote the health of all the trunk's tissues.

There are three chief types of blood vessels:

• Arteries. Arteries acquit oxygen-rich claret abroad from the center to all of the body's tissues. They branch several times, becoming smaller and smaller as they carry blood further from the heart and into organs.
• Capillaries. These are small, thin blood vessels that connect the arteries and the veins. Their thin walls permit oxygen, nutrients, carbon dioxide, and other waste matter products to pass to and from cells.
• Veins. These are claret vessels that take blood back to the center; this blood contains less oxygen and is rich in waste products that are to be excreted or removed from the torso. Veins become larger equally they get closer to the center. The superior vena cava is the big vein that brings blood from the head and arms to the heart, and the inferior vena cava brings blood from the belly and legs into the heart.

This vast system of blood vessels -- arteries, veins, and capillaries -- is over 60,000 miles long. That'due south long plenty to become around the world more than twice!

Blood flows continuously through your torso's blood vessels. Your heart is the pump that makes it all possible.

Where Is Your Heart and What Does It Look Like?

The heart is located under the rib muzzle, nether and to the left of your breastbone (sternum), and betwixt your lungs.

Looking at the outside of the heart, you can come across that the centre is fabricated of muscle. The potent muscular walls contract (clasp), pumping blood to the arteries. The major blood vessels that are connected to the middle include the aorta, the superior vena cava, the inferior vena cava, the pulmonary artery (which takes oxygen-poor blood from the heart to the lungs, where it is oxygenated), the pulmonary veins (which bring oxygen-rich blood from the lungs to the centre) and the coronary arteries (which supply claret to the heart muscle).

On the inside, the eye is a four-chambered, hollow organ. It is divided into the left and right side by a muscular wall called the septum. The correct and left sides of the middle are farther divided into ii top chambers called the atria, which receive blood from the veins, and two lesser chambers chosen ventricles, which pump blood into the arteries.

The atria and ventricles work together, contracting and relaxing to pump claret out of the heart in a coordinated and rhythmic way. As blood leaves each chamber of the eye, it passes through a valve. There are 4 heart valves within the heart:

• Mitral valve
• Tricuspid valve
• Aortic valve
• Pulmonic valve (likewise called pulmonary valve)

The tricuspid and mitral valves prevarication between the atria and ventricles. The aortic and pulmonic valves prevarication betwixt the ventricles and the major claret vessels leaving the middle.

The middle valves work the aforementioned way as one-style 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 chosen the annulus. The annulus helps to maintain the proper shape of the valve.

The leaflets of the mitral and tricuspid valves are likewise supported by tough, gristly 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.

How Does Blood Flow Through the Center?

The right and left sides of the heart work together. The design described below is repeated over and over, causing blood to flow continuously to the heart, lungs, and body.

Right side of the centre

• Blood enters the middle through two large veins, the inferior and superior vena cava, emptying oxygen-poor claret from the trunk into the correct atrium.
• As the atrium contracts, claret flows from your correct atrium into your right ventricle through the open up tricuspid valve.
• When the ventricle is total, the tricuspid valve shuts. This prevents blood from flowing backward into the right atrium while the ventricle contracts.
• Every bit the ventricle contracts, blood leaves the center through the pulmonic valve, into the pulmonary artery and to the lungs, where it is oxygenated. The oxygenated blood and so returns to the heart through the pulmonary veins.

Left side of the heart

• The pulmonary veins empty oxygen-rich blood from the lungs into the left atrium.
• As the atrium contracts, blood flows from your left atrium into your left ventricle through the open mitral valve.
• When the ventricle is full, the mitral valve shuts. This prevents blood from flowing backward into the atrium while the ventricle contracts.
• As the ventricle contracts, blood leaves the middle through the aortic valve, into the aorta and to the body.

How Does Blood Menstruum Through Your Lungs?

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 arteries and somewhen to tiny capillary vessels in the lungs.

Hither, oxygen travels from the tiny air sacs in the lungs, through the walls of the capillaries, into the claret. At the same time, carbon dioxide, a waste product product of metabolism, passes from the claret into the air sacs. Carbon dioxide leaves the body when y'all exhale. Once the blood is oxygenated, it travels back to the left atrium through the pulmonary veins.

What Are the Coronary Arteries?

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 claret from a network of arteries, chosen the coronary arteries.

Ii major coronary arteries co-operative off from the aorta near the point where the aorta and the left ventricle meet:

• Right coronary artery supplies the correct atrium and right ventricle with blood. It branches into the posterior descending avenue, which supplies the lesser portion of the left ventricle and dorsum of the septum with blood.
• Left primary coronary avenue branches into the circumflex artery and the left anterior descending artery. The circumflex avenue supplies blood to the left atrium, every bit well equally the side and dorsum of the left ventricle. The left anterior descending avenue supplies the forepart and bottom of the left ventricle and the front end of the septum with blood.

These arteries and their branches supply all parts of the heart muscle with claret.

When the coronary arteries narrow to the point that blood flow to the eye muscle is limited (coronary artery disease), a network of tiny claret vessels in the heart that aren't usually open up (called collateral vessels) may overstate and become active. This allows blood to menstruum around the blocked avenue to the eye muscle, protecting the centre tissue from injury.

How Does the Heart Beat?

The atria and ventricles work together, alternately contracting and relaxing to pump blood through your heart. This is your heartbeat. The electric system of your heart is the power source that makes this possible.

Your heartbeat is triggered by electrical impulses that travel down a special pathway through your centre.

• The impulse starts in a pocket-size parcel of specialized cells called the SA node (sinoatrial node), located in the right atrium. This node is known as the heart'south natural pacemaker. The electric activity spreads through the walls of the atria and causes them to contract.
• A cluster of cells in the center of the heart between the atria and ventricles, the AV node (atrioventricular node) is like a gate that slows the electrical signal earlier information technology enters the ventricles. This delay gives the atria fourth dimension to contract before the ventricles practise.
• The His-Purkinje network is a pathway of fibers that sends the electrical impulse from the AV node to the muscular walls of the ventricles, causing them to contract.

At residuum, a normal middle beats around fifty to ninety times a infinitesimal. Do, emotions, anemia, an overactive thyroid, fever, and some medications tin cause your heart to beat faster, sometimes to well over 100 beats per minute.

Heart Wellness Resources

You lot can learn more than almost your heart and eye health from these organizations and resource:

American Higher of Cardiology

world wide web.acc.org

American Heart Association

www.centre.org

Food and Drug Assistants

www.fda.gov

National Heart, Lung and Blood Institute Health Data Middle

www.nhlbi.nih.gov

CardioSmart

www.cardiosmart.org

The Heart.org

www.theheart.org

harrelltrailtandes.blogspot.com

Source: https://www.webmd.com/hypertension-high-blood-pressure/hypertension-working-heart

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