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How the Healthy Heart Works. The normal heart is a strong, hard-working pump made of muscle tissue. It's about the size of a person's fist. The heart has four chambers. The upper two chambers are the atria, and the lower two are the ventricles (Figure A). The chambers are separated by a wall of tissue called the septum. Functions of the Heart. Pumping blood is the chief and only function of the heart! Freshly oxygenated blood from the lungs enter the heart which is then pumped out to the rest of the body. After delivering oxygen to all tissues, the de-oxygenated blood returns to the heart, which the heart sends back to the lungs to get re-charged with oxygen.
Your heart is roughly the size of a fist and sits in the middle of your chest, slightly to the left. This blood sends oxygen and nutrients to all thr of your body, and carries away unwanted carbon dioxide and waste products. The two small upper chambers are the atria. The two larger lower chambers are the ventricles. These left and right sides of the heart are separated by a wall of muscle called the septum.
Your heart pumps blood around the body all the time - about five litres eight pints of it - and this is called circulation. Your heart, blood and blood vessels together make up your cardiovascular system or heart and circulatory system. The right side of the heart receives blood that is low in oxygen because most has been used up by the brain and body.
It pumps this to your lungs, where it picks up a fresh supply of oxygen. The blood then returns to the left side of the heart, ready to be pumped back out to the brain and the rest of your body. Blood what are the functions of heart are able to widen or narrow depending on how much blood each part of your body requires. This action is partly controlled by hormones. Your heart has four valves. They act like gates, keeping the blood moving in the right direction:.
For your heart to keep pumping regularly, it needs electrical signals which are sent to the heart muscle telling it when ard contract and relax.
This signal crosses the atria, making them contract. Blood is pumped through the valves into the ventricles. Where the atria meet the ventricles, there is an area of special cells - called the atrio-ventricular node - which pass the electrical signals throughout your heart muscle by a system of electrical pathways, known as the conducting system.
The what are the functions of heart of the ventricles then contract, and blood is pumped through the pulmonary and aortic valves into the main arteries. This is the measurement of the pressure within the arteries.
It plays a vital role funftions the way your heart delivers fresh blood to all your blood vessels. For blood to travel throughout your body quickly enough, it has to be under pressure. This is created by the relationship between three things:. One heartbeat is a single cycle in which fhe heart contracts and relaxes to pump blood.
At rest, the normal heart beats approximately 60 to times every minute, and it increases when you exercise. To ensure an adequate blood supply around your body, the four chambers of your heart have to pump regularly and in the right functione.
Watch this British Heart Foundation clip on how a healthy heart works. Some people are born with a heart that has not developed properly in the womb before birth - this is called congenital heart disease.
Sometimes you can inherit a heart condition from your family. Heart disease can happen when your coronary arteries become narrowed by a gradual build-up of fatty material - called atheroma. If your coronary arteries are narrowed or blocked, the blood supply to your heart will be impaired. This is the most common form of heart disease, known as coronary heart disease sometimes called coronary artery disease or ischaemic heart disease.
This can cause angina - a pain or discomfort in your chest, arm, neck, stomach or jaw. If the fatty material breaks off or ruptures, a blood clot will form, which can cause heart attack or stroke, if functionss artery affected is carrying blood to your brain.
Normally your heart will beat between 60 to times per minute. This regular rhythmic beating is dependent upon electrical signals being conducted throughout your heart. There are some conditions which can damage your heart muscle, making it weak and unable to pump as efficiently as before:. There are also conditions - like high blood pressure hypertension - which mean your heart has to work harder.
This is called heart failure because of the functikns of your heart to pump blood around what is the official length of the iditarod race body and work efficiently. Home Illnesses and conditions Heart and blood vessels About the heart Understanding how your heart functions. Understanding how your heart functions.
Structure of your heart Your heart is made up of three layers of tissue: epicardium myocardium endocardium. How does a healthy heart work? What can thf wrong? Structure Some people are born with a heart that has not developed properly in the womb before birth - this is called congenital heart disease. Cardiovascular system Problems with your heart and how to clean ceramic cooktop stains system include: heart attack angina stroke.
Sometimes these diseases are inherited from your family. Sometimes they are caused by other things, like viral infections. Share Tweet Print. Last updated:. How can we improve this page? Help us improve NHS inform. Email e. Message Maximum of characters. Send feedback. Community content from Health Unlocked.
Jul 31, · Function of the heart The heart is the main organ in the circulatory system, the structure is primarily responsible for delivering blood circulation and transportation of nutrients in all parts of. Sep 09, · The heart is an essential, powerful organ that constantly pumps oxygen and nutrients around the body. If a person is born with congenital heart disease, or . Functions of the heart: circulate blood throughout the body Cardiovascular system: heart and blood vessels Circulatory system: heart, blood vessels, and the blood Major divisions of the circulatory system 1. Pulmonary circuit – right side of heart a. Carries blood to lungs for gas exchange and back to heart 2. Systemic circuit – left side of heart a.
Pumping 2, gallons blood with , beats a day, the heart tirelessly works till your last breath. Larger hearts beat slower. Read on to discover fascinating facts about the function of heart.
In addition to elaborating on the heart function, the present article also provides an easy account of human heart structure, parts, diagram, location, and facts. To understand the heart structure and function, you can call it a muscular pump that contracts at regular intervals in order to squeeze the blood through it into the blood vessels. The location of the heart is in the same compartment which houses and safeguards the lungs — the thorax. Also called the chest, the thorax sits between the neck and the diaphragm and is partially encased by the ribcage.
Resting on the superior surface of the diaphragm , the heart is located posterior to the costal cartilages and the sternum. And the middle mediastinum can be defined as the space inside the pericardium, which forms a covering around the heart. According to Arthur Selzer, the heart is in the center of the chest , located slightly more to the left than to the right.
Two-thirds of the organ lies to the left of the midline while the remaining one-third goes to the right of the middle. The pulmonary component of the circulatory system begins at the junction between the right ventricle and the pulmonary artery. The purpose of this system is to purify the blood , i. The blood that the superior and inferior vena cavae collect from the upper and lower halves of the body, respectively, is deficient in oxygen.
Here it is to be noted that the pulmonary arteries are one of the two arteries that carry deoxygenated blood, the other being the umbilical arteries. A pulmonary artery shunts the blood away from the heart to the lung to re-saturate it with oxygen.
Numerous pulmonary capillaries diverged from the right and left pulmonary arteries help the blood take up oxygen and unload carbon dioxide in the lungs.
The upper left chamber then pushes it into the left ventricle via the left atrioventricular or mitral valve. The oxygen-rich blood leaves the heart and enters the aorta through the aortic valve, which marks the starting point of the systemic circulation. It starts at the aortic valve where the aorta — the largest artery in your body — joins the left atrium and ends at the junction of the superior and inferior vena cavae with the right atrium. Its job is to supply the peripheral organs and tissue beds with oxygen-rich blood and return the venous or oxygen-depleted blood back to the pumping organ.
While large and small arteries distribute the blood throughout the body, a network of veins recollects and brings it back for oxygenation. Serving as a connecting link between the arteries and veins, the capillaries are the exchange vessels. The main job of the capillaries is to facilitate the exchange of nutrients and fluid between the blood and the interstitial space. The pulmonary and coronary vascular circuits contain and percent of the total blood volume, respectively. It begins at coronary ostia where the ascending aorta starts branching off and ends at the junction between the coronary sinus and the right atrium.
Coronary arterial circulation and coronary venous circulation are the two subdivisions of this system. The former supplies the cardiac muscle tissue with oxygen and nutrients while the latter is concerned with the removal of carbon dioxide and waste products. So, the first destination of the oxygenated blood that leaves the left ventricle is the heart itself.
The right coronary artery divides to form conus branches anteriorly and the sinoatrial branch posteriorly. Many divisions and sub-divisions of the right and left arteries terminate in the capillary beds of the myocardium.
Most of the large veins converge to form the coronary sinus — the main venous channel. Other veins directly empty into the right atrium. But it differs in that it does not go through the vena cava and directly empties into the upper right chamber. Splanchnic circulation refers to the circulatory circuit committed to the blood supply to the splanchnic organs like the spleen, pancreas, liver, and gastrointestinal tract.
It involves all blood flow originating from three major arteries, viz. The components of the splanchnic circulation include splenic, pancreatic, hepatic, small intestinal, and gastric circulations. The splanchnic circulation can act as a blood reservoir and help regulate cardiac output. Maintenance of the body temperature is the primary job of the cutaneous circulatory circuit. The metabolically active regions of the brain are irrigated by this circulatory network. Involving the internal carotid and vertebral arteries, this supply network is tasked with the selectively and specifically pushing the blood to the master organ.
Another job of the cerebral circulation is to defend the brain from fluctuations in the concentrations of oxygen, carbon dioxide, and cerebral perfusion pressure. Researchers have recognized and appreciated the role of the heart in pumping the interstitial fluid from the blood into the extracellular space.
Afterwards, the lymphatic system is tasked with returning the excess fluid in the interstitial space back to the heart. A well-organized contraction of various parts of the organ is essential for the proper functioning of the circulatory system.
Specialized cells distributed through the heart serve as the sites for the origination and conduction of electrical impulses. While the pacemaker is responsible for the initiation of cardiac action, the conducting system is tasked with the distribution of the electrical impulses throughout the heart.
The specialized cardiac cells can be grouped into 3 types of structures: nodes, bundles with branches, and the terminal part of the branches. Here the 2 nodes consist of larger accumulations of cells and the bundles are nerve-like conduits. While all the specialized cells have the capacity to generate an electrical impulse, it is the S-A node that acts as the primary pacemaker and has the fastest rate of discharge.
The process involved in the regulation of electrical impulses is analogous to the discharge and recharge of a battery. Delivering a required amount of nutrients is one of the principal tasks assigned to the cardiovascular system.
After breakdown in different segments of the gastrointestinal canal, the digested food particles enter the bloodstream from the small intestine. The nutrients are also used as raw materials for growth, reproduction , and maintenance of various systems. Oxygen is the most essential fuel for all the tissues in your body. The hormones produced by a specific type of tissue need to be distributed to all cells of the body. Secreted into the extracellular fluid, hormones readily enter the blood through passive diffusion caused by steep concentration gradients.
As the principal organ of the circulatory system, your heart plays an important role in the transportation of the unwanted substances to the point of their removal. As you can see in the human heart diagram, there are 4 chambers in this tireless pumping organ. All the chambers work in a perfectly coordinated manner for the successful execution of different heart functions. Just look at the different parts of the heart to get a better understanding of the heart function. The heart structure consists of connective tissue and cardiac muscles.
The cardiac muscle contracts and relaxes on its own without requiring you to deliberately apply force. It measures 12 cm, 8 cm, and 6 cm along the length, width, and thickness, respectively. The effect of the exercise on the muscles of the heart organ is the same as shown by the skeletal muscles. The right atrium and ventricle contain oxygen-depleted blood collected from the upper and lower parts of the body through the superior and inferior vena cavae.
On the other hand, the left atrium and ventricle contain oxygen-rich blood, which is pumped through the whole body through the aorta. An inner lining, the heart muscle, and the outer covering are the 3 major layers of the heart.
The outer layer or pericardium can be distinguished into an outer lining or epicardium and a loose sac. While some are actively involved in the rhythmic contractions, others usually serve as standby pacemakers. In other words, different accumulations of cells or pacemakers are activated at different times in priority order.
Researchers have identified three types of pacemakers existing in your heart, i. Owing to the highest discharge rate, the SA node has been designated as the leading primary pacemaker. The SA or sinoatrial node is found at the junction of the right atrium and the superior vena cava. The discharge of the electrical potential from the SA node or the primary pacemaker activates the conduction system. An electrical impulse traveling through the conducting system induces contraction of the cardiac muscle.
After depolarization, the specialized cells in the SA node start rebuilding electrical potential for the next impulse. You can note that the process of the depolarization and repolarization in the heart is analogous to the discharge and recharge of a battery! The secondary pacemaker consists of the lower part of the AV node at its junction with the bundle of His. And the bundle of His emerges from the lower part of the AV node and enters the junction between the ventricles and the atria.
When the primary and secondary impulse formation systems stop working, the tertiary pacemaker is tasked with assuming their role. The tertiary pacemaker acts as the 3rd line of defense against the failure of the impulse to reach the lower chambers of the heart. The tertiary pacemaker consists of the lower divisions of the conducting system, including the Purkinje network.
The Purkinje network is formed from the division and subdivision of the principal branches left and right bundle branches of the bundle of His. Being slower than that of both the primary and secondary pacemakers, its rate of discharge is just about 30 to 40 times per minute. An interruption in the connection between the Purkinje system and the AV node serves as a trigger for the activation of the tertiary impulse formation unit.
It is because, obeying the primary pacemaker, the atria contract at a faster rate. And, under the influence of the tertiary pacemaker, the ventricles contract at a slower pace. To separately manage systemic and pulmonary circulations , your heart needs to maintain the unidirectional flow of the blood.
Two of them are located between the heart chambers to control the flow of the blood from the atria to the ventricles. The remaining two valves — pulmonary and aortic — control the flow of the blood out of the ventricles.
The mitral valve prevents the backflow of blood from the lower left chamber to the upper left chamber. Having 3 leaflets, the tricuspid valve is located between the right atrium and the right ventricle.
It stops the flow of deoxygenated blood back from the lower right chamber to the upper right chamber.
This check valve is located at the junction between the pulmonary artery and the right ventricle. In the presence of this valve, the oxygen-depleted blood from the pulmonary artery does not leak into the lower right chamber of the heart. Located between the largest artery — the aorta — and the left ventricle, the aortic valve regulates the flow of the oxygen-rich blood from the heart to the various tissues and organs of the body.
The coronary arteries and veins collectively make up the blood circulatory network dedicated to the heart muscle. Similarly, the coronary veins collect deoxygenated blood from the heart tissue and carry it to the right atrium for oxygenation.