Where is the heart of a person, where it is located, photo

Regular heart examinations can help determine the severity of heart symptoms in time and seek urgent medical attention if needed. The organ is located in a person's chest. To determine the causes of ailments, ECG diagnostics are used.

The heart is located in a person in the mediastinum and is the center of the circulatory system. It is located in the middle of the chest, tilted slightly to the left, and fits snugly against the lungs. The pointed end in the lower part touches the anterior chest wall. Every time the heart beats, it hits the chest wall.

Shape and dimensions

The heart has the shape of an obtuse cone, the base of which faces the posterior chest wall, and the apex faces the anterior chest wall. In an adult, the organ is about 12 cm long, 8 to 9 cm wide at its widest part, and about 6 cm thick. Weight ranges from 280 to 340 g for a man and from 230 to 280 g for a woman.

A normal healthy heart is about the size of an adult's fist. However, with some heart conditions, the heart can grow in size (dilate) and increase in weight and size with age. After age 65, the heart usually decreases, especially in people who are not physically active.

Anatomy

The heart is in a person in the heart bag, which consists of 2 layers: the outer layer (pericardium) and the inner layer (epicardium). Between them is a space containing a thin layer of liquid. Inside the heart, a muscular septum divides it into the left and right halves and separates the blood going to the lungs from the blood going to the rest of the body. Another wall separates the rounded top of the heart from the tapered bottom.

Cameras

There are 4 chambers (spaces) inside the organ: 2 left (atrium and ventricle) and 2 right (atrium and ventricle). Each upper chamber is called the atrium. The lower chambers are called the ventricles. The atria are often called the confinement chambers, and the ventricles are the pumping chambers. Thus, each side of the heart forms its own separate system, which do not communicate with each other. Blood flows from the upper to the lower chamber or ventricle, but not between the two sides.

Valve structures

Blood flows from the atria down to the ventricles because there are valves in the walls. They open in one direction like hatches. They then close so that blood cannot flow back into the atria. In this system, blood always flows in only one direction inside the heart. There are also valves at the bottom of the large arteries that carry blood from the heart: the aorta and pulmonary arteries.

These valves prevent blood from flowing back to the heart after being pumped out.

• The aortic valve consists of 3 sickle pockets. This ensures that blood is pumped into the aorta and not back into the left ventricle.
• The pulmonary valve also consists of 3 sickle pockets. The blood is pumped into the pulmonary artery and does not flow back to the right ventricle.
• The mitral valve consists of 2 cusps. This ensures that the left ventricle fills and that blood does not return to the left atrium.
• The tricuspid valve consists of 3 leaflets that allow the right ventricle to fill with blood and prevent it from returning to the right atrium.

Organ vascular system

The heart is in a person's chest and works like a pump. It pumps blood through the connections between arteries and veins known as the cardiovascular system.

The thick muscles that make up the heart can contract to allow blood to flow out. Blood does not spill everywhere when it comes out of the heart. It flows smoothly through the tubes, blood vessels. First, it flows through the arteries, vessels that leave the heart, which are thick tubes. They then branch out over and over again to form smaller tubes.

The smallest blood vessels, called capillaries, form a thin network of tiny ramifications throughout the body. The capillaries join together to form small veneules. These, in turn, connect to each other to form larger veins, until blood from the body finally collects into large veins that flow back into the heart. All blood from the body ultimately collects into the 2 largest veins: the superior vena cava, where blood flows from the upper body, and the inferior vena cava, into which blood flows from the lower part. Both vena cava drain blood flow into the right atrium of the heart.

Innervation

Heart organs and tissues are innervated by 3 sources:

Parasympathetic. (cholinergic system)	The neurons of the cardiac ganglia, which are second-order parasympathetic neurons, migrate directly from the neural crest to the heart. Parasympathetic nerve fibers slow down the heartbeat, narrow the lumen of the coronary arteries.
Sympathetic (adrenergic system)	Sympathetic nerve fibers arise from the thoracic sympathetic ganglia, which in turn originate from the cells of the thoracic crest. Sympathetic fibers transmit impulses that accelerate the heartbeat, expand the space of the coronary arteries.
Sensory nerves	The third component of innervation comes directly from the vagus nerve. Sensory fibers are part of the nerves of the spinal cord and brain.

The innervation heart apparatus is represented by a complex formation, which includes:

• nerve ganglia (clusters of nerve cells) located in the walls of an organ;
• cardiac nerves emanating from the thoracic aortic plexus;
• nerve endings (effectors and receptors).

Histological structure of the heart

The heart consists of 3 layers: epicardium, myocardium and endocardium.

• The inner wall of the organ is lined with an endocardium.
• The myocardium is made up of heart muscle cells that make up the middle layer and the bulk of the heart wall.
• The outer layer of cells is called the epicardium, the second layer of which is a layered membrane structure (pericardium) that surrounds and protects the heart. The pericardium leaves ample room for vigorous pumping, but it also holds the heart in place by reducing friction between the heart and other structures.

Physiology of cardiac activity

The physiology of cardiac activity includes the circulatory system, the automatism of the heart, cyclicity and regulation.

Cardiac activity

Heartbeats are caused by the heart's electrical conduction system. This system does not depend on the nervous system, which can only slow down or speed up contractions.

Conductivity cells are capable of generating cyclic electrical impulses. These electrical impulses originate in the wall of the right atrium, in the sinus node of the heart, and from there they are sent to other cells in the system.

The electrical activity of the heart is measured during the period of the ECG.

In a very simplified form, the work of the heart can be divided into 2 phases: systole, when it contracts to pump blood, and diastole, when the heart relaxes and fills with blood.

Each electrical pulse takes about 0.22 seconds to complete a cycle. On average, the heart beats about 100 thousand. once a day. During the average life of a person, the heart will beat more than 2.5 billion times.

Circulation

The circulatory system works due to the fact that the heart, supports the movement of blood in a closed circuit, which begins and ends in the heart itself.

The closed circuit consists of 2 parts, the systemic cycle and the pulmonary loop. In the systemic cycle, blood circulates in the systems of the body, delivering oxygen to all its organs, structures and tissues and collecting waste carbon dioxide. In the pulmonary loop, blood circulates to and from the lungs, releasing carbon dioxide and taking in new oxygen. The systemic cycle is controlled by the left side of the heart, the pulmonary cycle is controlled by the right side of the heart.

Each heartbeat causes a constant movement of blood, so it is pushed back to the heart, where the process repeats.

Heart cycle

Heart rate is a sequence of events that occurs when the heart beats. It includes diastole, systole and intermediate pause. In the diastole phase, the heart ventricles relax and the heart fills with blood. During the systole phase, the ventricles contract and pump blood from the heart to the arteries.

The contraction of the heart muscle begins in the two atria, which push blood into the ventricles. The walls of the ventricles then contract and push blood into the arteries: the aorta to the body and the pulmonary artery to the lungs. The heart muscle then relaxes, allowing blood to flow from the veins and refill the atria. In healthy people, a normal heart rate (at rest) is about 72 beats per minute, but it can be much higher during exercise. Scientists have calculated that it takes about 30 seconds to complete the entire cycle of 1 portion of blood: from the lungs to the heart and to the body, back to the heart and then to the lungs.

Automatism

Part of the heart muscle works in such a way that it gives out signals or impulses to all other parts. The system is called conductive. Consists of a number of nodes and bundles of fibers, and each electrical impulse travels the same path.

• The sinoatrial node is where the impulse is initiated.
• The impulse then travels to the atrioventricular node (where it pauses).
• Then it goes to the His bundle.
• Culminates in Purkinje fibers.

Between the sinoatrial and atrioventricular nodes, the atria contract, pumping blood into the ventricles.

From the bundle of His, the impulse passes through the bundle branches of each ventricle. Between the branches of the bundles and the Purkinje fibers, the ventricles contract, pumping blood out of the heart.

Conjugation of excitement and contraction

Excitation-contraction is a physiological process of converting an electrical stimulus into a mechanical response. The fibers of the heart muscle contract through the interaction of excitation and contraction using a mechanism unique to the heart muscle called the release of calcium ions by calcium.

The excitation-contraction relationship describes the process of converting an electrical stimulus (action potential) into a mechanical response (muscle contraction).

Calcium-induced ion release involves the transport of calcium ions into the cardiomyocyte, the muscle cells of the heart that make up the heart of the myocardium.

Regulation of the work of the organ

Certain mechanisms regulate cardiac activity and are responsible for the smooth functioning of the organ.

Intracardiac

The work consists in increasing the stroke volume of the heart in response to the increasing volume of blood in the ventricles before systole. This is necessary to maintain an equal level of blood passing through the ventricles, right and left.

 Extracardiac

The human heart is the main working link of reflexes that originate in blood vessels, organs, muscles, and skin. All reflexes are performed at different levels of the autonomic nervous system. The vasomotor nerve, which is located in the medulla oblongata, is part of the autonomic nervous system. It receives signals from receptors that help it regulate cardiac activity or cardiac reflexes.

Hormonal influences are also referred to regulation. Thus, thyroid hormones enhance cardiac activity.

Instrumental methods for diagnosing the work of the heart

Instrumental methods include the study of the function of cardiac activity using various devices.

Ultrasound examination of the heart

Ultrasound is used to study the structure of an organ, its pathological changes, hemodynamics.

Electrical phenomena

The heart muscles, during their work, cause the appearance of an electromagnetic field. With the help of an electrocardiograph, the electrical activity of the heart is studied. The technique is used in the diagnosis of heart attacks and other diseases.

Acoustic phenomena

Auscultation is necessary when examining heart sounds that are associated with valve closure.

Mechanical activity

Methods that give an idea of ​​the dynamics of the heartbeat include:

• kinetocardiography;
• electrokymography;
• dynamocardiography;
• photocardiography.

How and where the heart hurts, irradiation, prevalence, duration of pain

The heart is in a person's chest. With pain, a person feels a dull, oppressive feeling. If the pain is aching, sharp, burning, or stabbing, it could be caused by a condition such as acid reflux or heartburn, pleurisy, costal chondritis, or aortic dissection.

If the pain is on the right side, a heart attack is unlikely (unless there is a rare condition called dextrocardia). Heart attack pain usually appears vague and non-localized. If it has a pinpoint location, then it is unlikely to be a heart attack. The nerves in the region of the heart overlap, so heart pain can occur in the left side of the neck and left arm. This is called reflected pain.

Heart attack pain can be intermittent or constant. Heart attack symptoms can last from a few minutes to several hours. If chest pain is present continuously for days, weeks, or months, it is unlikely to be caused by a heart attack. Pain during a heart attack is usually relieved at rest.

Angina pectoris

Angina is a feeling of tightness, discomfort, or pain in the middle of the chest. Such complaints arise from narrowing of the coronary arteries and indicate that the heart is poorly supplied with blood.

The symptoms of angina pectoris vary.

• With stable angina pectoris, suffocation or burning pain occurs behind the sternum, which, as a rule, radiates to the left arm, but sometimes to the shoulder, neck, chin and back. The pain decreases after a few minutes or disappears after taking nitrate-like drugs.
• With unstable angina, symptoms develop over several hours or days, worsen rapidly, and last more than 15 minutes. Complaints occur for no apparent reason, as well as at night or at rest. Unstable angina is a precursor to a heart attack and therefore requires urgent care.

Unlike a heart attack, this decrease in blood flow does not usually cause permanent damage to the heart muscle, but means that there is a high risk of a heart attack.

Heart attack

A myocardial infarction or heart attack occurs when blood flow to the heart tissue through the coronary arteries is obstructed (usually due to a buildup of plaque). If oxygenated blood cannot reach the tissue, the tissue will die, weakening the heart and leaving scarring.

Inflammatory processes

Inflammation is differentiated depending on which part of the heart is affected. Most inflammation is due to external stimuli, such as those caused by bacteria, viruses, fungi, or parasites.

Inflammation can be caused by the body itself, such as an autoimmune disease. Depending on which part of the heart is affected, they speak of endocarditis, myocarditis or pericarditis.

Endocarditis affects the inner wall of the heart, myocarditis affects the heart muscle, and pericarditis affects the pericardium.

• Endocarditis It is caused by bacteria, less commonly fungi, that enter the bloodstream through damage to the skin or mucous membrane and colonize the endocardium. The heart valves are most commonly affected. Endocarditis is rare but can be life threatening. People with heart disease, artificial heart valves, or congenital heart disease are at increased risk of endocarditis. The best prevention of endocarditis is good dental and skin hygiene.
• Myocarditis Is an inflammation of the heart muscle. The causes of the myocardium are mainly viruses, less often autoimmune diseases, bacteria and parasites. In most cases, this is accompanied by mild malaise, as with other viral infections, or even goes unnoticed. If myocarditis is suspected, physical rest is usually sufficient.
• Pericarditis Is an inflammation of the heart sac. Like myocarditis, pericarditis is usually caused by a viral infection. In most cases, pericarditis resolves spontaneously.

Arterial pathology

Atherosclerosis, or hardening of the arteries, is an inflammatory process that damages the inner layer of the arteries. The walls of the arteries lose elasticity and thicken. Deposits of cholesterol - fat in the blood - and calcium form cushions, called plaques, and constrict blood flow. If these plaques break off, blood clots form at the point of rupture, which can completely block blood flow.

Valve lesions

Any of the four heart valves can get sick. However, the aortic and mitral valves are most commonly affected.

Diseases are divided into 2 groups:

• Stenosis. The heart valve thickens and calcifies. It becomes dense, does not open properly, and can no longer pass enough blood.
• Insufficient valve. The heart valve, for example, after inflammation, does not close completely. The valve does not work stably, the blood flows back.

Valve disease is the result of wear and tear and is more common with age. Other causes include enlargement of the chambers of the heart in the case of heart failure, rheumatic or bacterial inflammation with destruction of parts of the valves.

Cardiomyopathy

There are 3 main forms of cardiomyopathy development:

Dilation. (DCMP)	In DCM, the left ventricle expands and becomes thinner. About half of the cases are caused by a hereditary predisposition. Other causes include severe viral infections, alcoholism, or, in rare cases, pregnancy.
Hypertrophic cardiomyopathy (HCMP)	With HCM, the left ventricle thickens. The reason is hereditary predisposition.
Restrictive cardiomyopathy (RCM)	In RCM, the left ventricle becomes stiff because normal muscle tissue is replaced by scar tissue. The reasons are rare connective tissue diseases or metabolic disorders, as well as hereditary predisposition.

In addition to the 3 main forms, there are other forms of cardiomyopathy. They are caused by certain triggers such as infections, high blood pressure, heart defects, or metabolic disorders.

In cardiomyopathy, the function of the heart muscle is limited. There are also cardiac arrhythmias up to sudden cardiac death. Usually people under the age of 50 get sick, and more often men than women. Cardiomyopathies are the leading cause of sudden cardiac death in young men.

How to distinguish heart pain from neuralgia?

The most common diagnoses are intercostal neuralgia and cardiology (cardiac neuralgia), with the first the disease proceeds relatively well, and the second can be complicated by serious pathological states.

Both types of neuralgia are characterized by chest pain. But there are other clinical signs that help distinguish one disease from another.

For chest pain with cardiac neuralgia, the following features are characteristic:

• pain occurs periodically;
• defined as dull, oppressive, suffocating;
• eliminated by "heart" drugs (nitroglycerin);
• not associated with body movements;
• often occurs without clear localization;
• can be given to the lower jaw, left hand;
• most often defined on the left side, where the heart is.

In addition, with cardiac neuralgia, there may be a violation of the heart (arrhythmia) or an increase or decrease in blood pressure.

Distinctive signs of chest pain that develops with intercostal neuralgia:

• pain depends on body movements, especially when sneezing, laughing, coughing;
• in general, it is constant, although sometimes patients note its episodicity;
• not removed by nitroglycerin or other "heart" drugs;
• when palpating the affected area, pain increases.

What is the difference between heart pain and stomach pain?

The heart is located in a person in the immediate vicinity of the esophagus. They receive very similar nervous nourishment. Thus, pain from any organ travels through the same sensory nerve fibers to the brain. As a result, pain in any organ can have very similar features, making it difficult to differentiate heart pain from pain in the esophagus.

A heart attack is usually caused by a blood clot that forms in a coronary artery. This blocks blood flow to the heart and often causes cramping or constricting pain in the center of the chest. Sometimes this pain can spread to the left arm, neck, sternum.

 Disorders with pain similar to a heart attack:

• Heartburn, a burning sensation in the abdomen or behind the breastbone.
• Peptic ulcer, destruction of the lining of the stomach or upper part of the small intestine.
• Gastritis.
• Pancreatitis
• Diseases of the gallbladder, including cholecystitis.
• Hepatitis, infection or inflammation of the liver.

If there is sudden abdominal pain and additional symptoms described below appear, this could indicate a heart attack:

• feeling dizzy or fainting;
• weakness;
• pain in the shoulder, neck, arms, back, teeth, or jaw;
• pain, squeezing, or any unpleasant sensation in the chest;
• dyspnea.

Some possible signs of heart disease include rapid heart rate, dizziness, and fatigue. While these may be symptoms of other medical conditions, it is best to consult a doctor for a diagnosis. Treatment can help slow the progression of heart disease and reduce the risk of complications.

Author: Belyaeva Anna

Video about heart anatomy

Anatomy of the heart: