How to draw a real heart. Anatomy and physiology of the heart: structure, functions, hemodynamics, cardiac cycle, morphology

The human heart has four chambers: two ventricles and two atria. Arterial blood flows through the left sections, venous blood flows through the right. The main function is transport; the heart muscle works like a pump, pumping blood to peripheral tissues, supplying them with oxygen and nutrients. When cardiac arrest occurs, it is diagnosed clinical death. If this condition continues for more than 5 minutes, the brain shuts down and the person dies. This is the whole importance of the proper functioning of the heart; without it, the body is not viable.

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Diagram of the structure of the heart

The heart is an organ consisting of to a greater extent from muscle tissue, it provides blood supply to all organs and tissues and has the following anatomy. Located in the left half of the chest at the level of the second to fifth rib, the average weight is 350 grams. The base of the heart is formed by the atria, pulmonary trunk and aorta, turned towards the spine, and the vessels that make up the base fix the heart in the chest cavity. The apex is formed by the left ventricle and is a rounded area facing down and to the left towards the ribs.

In addition, the heart has four surfaces:

Anterior or sternocostal.
Lower or diaphragmatic.
And two pulmonary: right and left.

The structure of the human heart is quite complex, but it can be described schematically as follows. Functionally, it is divided into two sections: right and left or venous and arterial. The four-chamber structure ensures the division of blood supply into a small and large circle. The atria are separated from the ventricles by valves that open only in the direction of blood flow. The right and left ventricles are separated by the interventricular septum, and the interatrial septum is located between the atria.

The heart wall has three layers:

The epicardium is the outer membrane, tightly fused with the myocardium, and covered on top with a pericardial sac - the pericardium, which delimits the heart from other organs and, due to its contents, large quantity fluid between its leaves provides a reduction in friction during contraction.
Myocardium - consists of muscle tissue, which is unique in its structure; it provides contraction and carries out excitation and conduction of impulses. In addition, some cells have automatism, that is, they are able to independently generate impulses that are transmitted along pathways throughout the myocardium. Muscle contraction occurs - systole.
Endocardium - covers inner surface atria and ventricles and forms the heart valves, which are folds of the endocardium consisting of connective tissue with a high content of elastic and collagen fibers.

The structure of the myocardium

The thickest layer of the heart is the muscular layer; in the area of the left ventricle it reaches a thickness of 11 to 14 mm, which is 2 times greater than the wall of the right ventricle (4 to 6 mm). In the area of the atria, the muscle layer is even smaller - 2–3 mm. The myocardium of the atria and ventricles is separated by a fibrous ring; it surrounds the right and left atrioventricular orifices. The structure of the myocardium of the atria and ventricles is also different; the former have two muscle layers, and the latter three. This indicates a greater functional load on the lower parts of the heart.

The muscle fibers of the atria form the so-called ears, which are a continuation of the chambers of the upper parts of the heart. The right and left ears are distinguished. The ventricular myocardium forms papillary muscles, from which chords extend to the mitral and tricuspid valves. They are needed so that the high pressure of the ventricles does not bend the valve leaflets into the atria and does not push blood in the opposite direction.

The interatrial and interventricular septum are formed by muscle tissue. Only the latter has a membranous part, in which there are practically no muscle fibers; it occupies 1/5 of the entire surface, the remaining 4/5 of the surface is the muscular section, reaching a thickness of up to 11 mm.

Heart valves and hemodynamics

Diagram of blood flow through the chambers of the heart

To ensure the correct sequence of blood flow, valves are placed between the chambers. The right atrium and ventricle are separated by the tricuspid valve (tricuspid), and the left by the mitral valve (bicuspid). In addition, there are valves in both the pulmonary trunk and the aorta, their function is the same - to prevent the reverse flow of blood from the arteries to the heart.

When the atria contract, blood is pushed into the ventricles, after which the tricuspid and mitral valves close, and the latter begin to contract, carrying blood into the pulmonary trunk and aorta. This is how the large and small circles of blood circulation begin, the hemodynamic mechanism for them looks as follows.

The pulmonary trunk emerges from the right ventricle, it divides into the right and left pulmonary arteries, they carry venous blood to the lungs for oxygenation. The oxygenated blood then returns through the four pulmonary veins to the left atrium. This is what the pulmonary circulation looks like.

The division of vessels into arteries and veins depends not on what kind of blood they carry, but on the direction relative to the heart. An artery is any vessel coming from the heart, and a vein is called any vessel leading to it. Therefore, in the pulmonary circulation, arteries carry venous blood, and veins carry arterial blood.

Then from the left atrium the blood enters the left ventricle, and from it into the aorta - the beginning of the great circle. Blood carries oxygen and nutrients through the arteries to the tissues; as it approaches the periphery, the diameter of the vessels decreases and gas exchange and release of nutrients occur at the capillary level. After these processes, the blood becomes venous and is directed through the veins to the heart. Two vena cava flow into the right atrium - superior and inferior. And the big circle ends.

The heart has about 60–80 such cycles per minute, with a volume of about 5–6 liters. During its entire life, it carries about 6 million liters of blood. This is a colossal work performed every second to ensure the normal life of the body.

Conducting system

Conduction system of the heart

The conduction system is responsible for the correct and consistent contraction of the myocardium by transmitting excitation along muscle fibers. It consists of a complex of formations consisting of atypical muscle cells capable of automaticity, conduction and excitation. Includes the following entities:

Sinus node (Kisa-Flaca) - it is located in the right atrium at the mouth of the vena cava, and is the main pacemaker of the human heart. It consists of specialized muscle cells (Pacemakers) capable of generating impulses at a frequency of 60–80 per minute.
Three internodal tracts and one interatrial tract arise from the sinus node (SU). The first ones transmit the impulse from the suture block to the atrioventricular one, and the second one ensures its conduction to the left atrium.
Atrioventricular node (AVN) - its task is to transmit excitation to the ventricles, but it does not do this immediately, but after such a phenomenon as atrioventricular delay. It is necessary so that the atria and ventricles do not contract at the same time, since the latter simply will not have anything to pump into the vessels.
The Hiss bundles are divided into right and left according to their location in the heart. The first innervates the right ventricle, and the left is divided into two branches - anterior and posterior and is responsible for excitation of the left ventricle.
The latest and greatest small elements The conduction system is Purkinje fibers - they are diffusely separated in the thickness of the myocardium and directly transmit the impulse to the muscle fiber.

The existence of such a clear sequence ensures normal cardiac cycle and blood supply to tissues.

Blood supply to the myocardium

Coronary arteries

The heart is an organ like others, and it also needs blood, the myocardium does not feed on blood from the cavities of the heart, for this there is a separate circulatory system, which some authors even call the third circle of blood circulation. At the beginning of the aorta, two coronary (coronary) arteries branch off to the heart: the right and left. They divide dichotomously and give off smaller branches to the myocardium. The left coronary artery supplies the anterior wall of the heart, the interventricular septum and the apex, while the right one supplies the posterolateral part of the myocardium. The outflow of blood occurs through the capillaries and then through the coronary veins to the right atrium.

A feature of the coronary circulation is that the arteries fill at the moment the myocardium relaxes, so during diastole the heart not only “rests”, but also nourishes. Disturbances in the blood flow of the heart lead to diseases such as coronary heart disease, angina pectoris and myocardial infarction.

Work of the heart

The cardiac cycle (CC) is the successive phases of systole (contraction), diastole (relaxation) and the subsequent general pause. During diastole, the heart fills with blood, first the atria and then the ventricles. After which myocardial contraction occurs, and the chambers are freed of blood. On average, the duration of atrial systole is from 0.1 to 0.17 seconds, and ventricular systole is 0.33–0.47 seconds.

Phases of the cardiac cycle

The ventricles account for more hard work, since they must push blood into vessels of smaller diameter and with such force that it reaches the periphery. Therefore, the muscle wall in them is much thicker.

The duration of the cardiac cycle depends on the number of heartbeats. So at rest it will be larger, but at physical activity less. On average, one SP lasts 0.8 seconds if the heart rate is 75 beats per minute.

Schematically, this process can be described as follows: from the superior and inferior vena cava and pulmonary veins, blood enters the atria, where pressure begins to increase and the myocardium stretches. Under the influence of these factors, atrial systole occurs. Next, the blood enters the ventricles and, according to the same principle, is pushed into the pulmonary trunk and aorta.

When the ventricles contract, the atrium is in diastole, and vice versa. But there is also certain time, in which both the ventricles and atria are simultaneously in the relaxation phase, and then in a general pause.

To ensure adequate nutrition internal organs, the heart pumps an average of seven tons of blood per day. Its size is equal to a clenched fist. Throughout life, this organ makes approximately 2.55 billion beats. The final formation of the heart occurs by the 10th week of intrauterine development. After birth, the type of hemodynamics changes dramatically - from feeding on the mother’s placenta to independent, pulmonary breathing.

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Muscle fibers (myocardium) are the predominant type of heart cells. They make up its bulk and are located in the middle layer. The outside of the organ is covered with epicardium. It wraps at the level of the attachment of the aorta and pulmonary artery, heading downwards. In this way, the pericardial sac is formed. It contains about 20 - 40 ml of clear liquid, which prevents the leaves from sticking together and being injured during contractions.

The inner membrane (endocardium) folds in half at the transition of the atria into the ventricles, the mouths of the aortic and pulmonary trunk, forming valves. Their valves are attached to a ring of connective tissue, and the free part moves with the blood flow. In order to prevent the parts from everting into the atrium, threads (chords) are attached to them, extending from the papillary muscles of the ventricles.

The heart has the following structure:

three membranes - endocardium, myocardium, epicardium;
pericardial sac;
chambers with arterial blood - left atrium (LA) and ventricle (LV);
sections with venous blood - right atrium (RA) and ventricle (RV);
valves between the LA and LV (mitral) and tricuspid on the right;
two valves separate the ventricles and large vessels (aortic on the left and pulmonary artery on the right);
the septum divides the heart into right and left halves;
efferent vessels, arteries - pulmonary (venous blood from the pancreas), aorta (arterial from the left ventricle);
afferent veins - pulmonary (with arterial blood) enter the LA, vena cava flow into the RA.

Internal anatomy and structural features of valves, atria, ventricles

Each part of the heart has its own function and anatomical features. In general, the LV is more powerful (compared to the right), as it forces blood into the arteries, overcoming the high resistance of the vascular walls. The PP is more developed than the left, it receives blood from the whole body, and the left one only from the lungs.

Which side of a person's heart is on?

In humans, the heart is located on the left side in the center of the chest. The main part is located in this area - 75% of the total volume. One third extends beyond the midline into the right half. In this case, the axis of the heart is inclined (oblique direction). This situation is considered classic, as it occurs in the vast majority of adults. But options are also possible:

dextrocardia (right side);
almost horizontal - with a wide, short chest;
close to vertical - for thin people.

Where is a person's heart located?

The human heart is located in the chest between the lungs. It is adjacent to the sternum from the inside, and is limited below by the diaphragm. It is surrounded by the pericardium, the pericardium. Pain in the heart area appears on the left near the mammary gland. The top is projected there. But with angina, patients feel pain behind the sternum, and it spreads along the left side of the chest.

Where is the heart located in the human body?

The heart in the human body is located in the center of the chest, but its main part goes into the left half, and only one third is located on the right side. For most it has an angle of inclination, but for fat people its position is closer to horizontal, and for thin people it is closer to vertical.

Location of the heart in the human chest

In humans, the heart is located in the chest in such a way that its anterior and lateral surfaces are in contact with the lungs, and its posterior and inferior surfaces are in contact with the diaphragm. The base of the heart (from above) passes into large vessels - the aorta, pulmonary artery. The apex is the lowest part, it approximately corresponds to the 4-5 space between the ribs. It can be found in this area by lowering an imaginary perpendicular from the center of the left collarbone.

The external structure of the heart refers to its chambers; it contains two atria and two ventricles. They are separated by partitions. The pulmonary veins, the vena cava, enter the heart, and the arteries of the lungs, the aorta, carry the blood out. Between the large vessels, at the border of the atria and ventricles of the same name, there are valves:

aortic;
pulmonary artery;
mitral (left);
tricuspid (between the right parts).

The heart is surrounded by a cavity containing a small amount of fluid. It is formed by the pericardial layers.

If you clench your fist, you can imagine exactly the appearance of a heart. In this case, the part that is located at the wrist joint will be its base, and the acute angle between the first and thumb- the top. What is important is that its size is also very close to a clenched fist.

This is what a human heart looks like

Borders of the heart and their projection onto the surface of the chest

The boundaries of the heart are found by percussion, by tapping; radiography or echocardiography helps to determine them more accurately. The projections of the cardiac contour onto the surface of the chest are:

right – 10 mm to the right of the sternum;
left – 2 cm inward from the perpendicular from the center of the collarbone;
apex – 5th intercostal space;
base (upper) – 3rd rib.

What tissues make up the heart?

The heart consists of the following types of tissue:

muscle - the main one, is called the myocardium, and the cells are cardiomyocytes;
connective – valves, chords (threads that hold the valves), outer (epicardial) layer;
epithelium – inner lining (endocardium).

Surfaces of the human heart

The human heart has the following surfaces:

ribs, sternum – anterior;
pulmonary – lateral;
diaphragmatic – lower.

Apex and base of the heart

The apex of the heart is directed down and to the left, its localization is the 5th intercostal space. It represents the top of the cone. Wide part(base) is located on top, closer to the collarbones, and is projected at the level of the 3rd rib.

Human heart shape

Heart shaped healthy person looks like a cone. Its tip is directed at an acute angle down and to the left of the center of the sternum. The base contains the mouths of large vessels and is located at the level of the 3rd rib.

Right atrium

Receives blood from the vena cava. Next to them is the foramen ovale, which connects the RA and LA in the fetal heart. In a newborn, it closes after the pulmonary blood flow opens, and then completely heals. During systole (contraction), venous blood passes into the pancreas through the tricuspid valve. The RA has a fairly powerful myocardium and a cubic shape.

Left atrium

Arterial blood from the lungs passes into the LA through 4 pulmonary veins and then flows through the opening into the LV. The walls of the LA are 2 times thinner than those of the right one. The shape of the LP is similar to a cylinder.

Right ventricle

It looks like an inverted pyramid. The capacity of the pancreas is about 210 ml. It can be divided into two parts - the arterial (pulmonary) cone and the ventricular cavity itself. In the upper part there are two valves: the tricuspid and the pulmonary trunk.

Left ventricle

It looks like an inverted cone, its lower part forms the top of the heart. The thickness of the myocardium is the largest - 12 mm. There are two openings at the top - for connection with the aorta and LA. Both of them are covered by valves - the aortic and mitral.

Why are the walls of the atria thinner than the walls of the ventricles?

The thickness of the walls of the atrium is less, they are thinner, since they only need to push blood into the ventricles. The right ventricle follows them in strength; it throws its contents into the neighboring lungs, and the left one is the largest in terms of the size of its walls. It pumps blood to the aorta, where there is high pressure.

Tricuspid valve

The right atrioventricular valve consists of a sealed ring that limits the opening and leaflets; there may be not 3, but from 2 to 6.

Half of the people have a tricuspid configuration.

The function of this valve is to prevent the reflux of blood into the RA during RV systole.

Pulmonary valve

It prevents blood from passing back into the pancreas after it contracts. The composition contains valves similar in shape to a crescent. In the middle of each there is a knot that seals the closure.

Mitral valve

It has two doors, one is in the front and the other is in the back. When the valve is open, blood flows from the LA to the LV. When the ventricle contracts, its parts close together to allow blood to pass into the aorta.

Aortic valve

Formed by three semilunar-shaped flaps. Like the pulmonary one, it does not contain threads that hold the valves in place. In the area where the valve is located, the aorta expands and has depressions called sinuses.

Adult heart weight

Depending on body type and total weight body weight of the heart in an adult varies from 200 to 330 g. In men, it is on average 30-50 g heavier than in women.

Diagram of blood circulation

Gas exchange occurs in the alveoli of the lungs. They receive venous blood from the pulmonary artery emerging from the pancreas. Despite the name, the pulmonary arteries carry venous blood. After the release of carbon dioxide and oxygen saturation through the pulmonary veins, the blood passes into the left atrium. This is how a small circle of blood flow, called pulmonary, is formed.

The large circle covers the entire body as a whole. From the LV, arterial blood spreads to all vessels, nourishing the tissues. Deprived of oxygen, venous blood flows from the vena cava into the RA, then into the RV. The circles close together, ensuring a continuous flow.

In order for blood to enter the myocardium, it must first pass into the aorta and then into the two coronary arteries. They are named so because of the shape of the branches, reminiscent of a crown (crown). Venous blood from the heart muscle predominantly enters the coronary sinus. It opens into the right atrium. This circle of blood circulation is considered the third, coronary.

Watch the video about the structure of the human heart:

What is special about the structure of a child’s heart?

Until the age of six, the heart is spherical due to the large atria. Its walls are easily stretched, they are much thinner than those of adults. A network of tendon threads is gradually formed, fixing the valve leaflets and papillary muscles. Full development of all heart structures ends by age 20.

The position of the newborn's heart in the chest is initially oblique, adjacent to the anterior surface. This is caused by an increase in the volume of lung tissue and a decrease in the mass of the thymus gland.

Until two years of age, the heart impulse forms the right ventricle, and then part of the left. The atria are the leaders in growth rate up to 2 years, and the ventricles after 10 years. Up to ten years, the LV is ahead of the right.

Basic functions of the myocardium

The heart muscle differs in structure from all others, as it has several unique properties:

Automatism is excitation under the influence of one’s own bioelectric impulses. They first form in the sinus node. He is the main pacemaker, generating about 60 - 80 signals per minute. The underlying cells of the conducting system are nodes of the 2nd and 3rd order.
Conduction - impulses from the site of formation can spread from the sinus node to the RA, LA, atrioventricular node, and along the ventricular myocardium.
Excitability - in response to external and internal stimuli, the myocardium is activated.
Contractility is the ability to contract when excited. This function creates the pumping capabilities of the heart. The force with which the myocardium reacts to an electrical stimulus depends on the pressure in the aorta, the degree of stretching of the fibers in diastole, and the volume of blood in the chambers.

The functioning of the heart goes through three stages:

Contraction of the RA, LA and relaxation of the RV and LV with the opening of the valves between them. Transition of blood into the ventricles.
Ventricular systole - the valves of the blood vessels open, blood flows into the aorta and pulmonary artery.
General relaxation (diastole) - blood fills the atria and presses on the valves (mitral and tricuspid) until they open.

During the period of contraction of the ventricles, the valves between them and the atria are closed by blood pressure. In diastole, the pressure in the ventricles drops, it becomes lower than in large vessels, then parts of the pulmonary and aortic valves close so that the blood flow does not return.

Heart cycle

There are 2 stages in the heart cycle: contraction and relaxation. The first is called systole and also includes 2 phases:

compression of the atria to fill the ventricles (lasts 0.1 sec.);
the work of the ventricular part and the release of blood into large vessels (about 0.5 sec.).

Then comes relaxation - diastole (0.36 sec). Cells change polarity to respond to the next impulse (repolarization), and the blood vessels of the myocardium bring nutrition. During this period, the atria begin to fill.

The heart ensures the movement of blood through the large and small circles thanks to the coordinated work of the atria, ventricles, great vessels and valves. The myocardium has the ability to generate an electrical impulse and conduct it from the nodes of automaticity to the cells of the ventricles. In response to the signal, muscle fibers become active and contract. The cardiac cycle consists of a systolic and a diastolic period.

Useful video

Watch the video about the work of the human heart:

Simple ways

And so, let's figure out how to beautifully draw a heart with a pencil step by step for beginners. All we need is a sheet of paper, a simple pencil, and, of course, due perseverance in this endeavor. To make the heart cute, you need to make it symmetrical, and to do this, do a couple of simple steps:

Draw two identical circles on a piece of paper in the same horizontal plane so that both circles intersect slightly. Let’s immediately say that the upper halves of the circles will help create beautiful symmetrical edges of the heart. Accordingly, those parts that make up the main drawing can be drawn boldly, and those that need to be removed can be made weaker. It is advisable to draw circles by hand, it’s okay if at first the circle doesn’t turn out very round, this will improve with practice. But if you are not initially satisfied with the quality of the circles, you can resort to auxiliary means.

The next figure in the figure is a cross. The vertical line of the cross should pass along the intersection of the circles; to form it, it is enough to draw a line through two points at which the circles from the first point intersected. It doesn’t make sense to raise the vertical line high in length; its lower part is more useful for the drawing, so don’t skimp and lower it down. In order to understand how low you should go, ask yourself: how to draw a heart beautifully, what proportions in height will be optimal for you so that the drawing turns out beautiful. The horizontal line is drawn perpendicular to the vertical in the middle of both circles.

From extreme points At the intersection of the circles with a horizontal line, lower two smooth symmetrical lines to the bottom point of the heart. You should determine the position of this lowest point yourself, because because of this
parameter the heart will turn out to be more elongated or more flattened.

Point thick line semicircles of each circle upward from horizontal line and to the first intersection point.

At this stage, drawing the heart is complete. All that remains is to remove the extra lines used in the construction and create the resulting drawing.

The perfect heart in terms of symmetry and shape is already in front of you. Of course it's not the only way, allowing you to draw a heart.

An easier option for advanced artists

If the previous version seemed boring and unattractive to you due to the presence of a large number of additional constructions, if you need to complete the drawing much faster and there is no way to build circles, if you feel you have sufficient level and skills, we bring to your attention the second method of how to draw a heart pencil step by step. But let’s make a reservation right away: you must be good at drawing symmetrical circles, otherwise the heart will turn out to be asymmetrical.

Divide the sheet into four parts with two perpendicular lines, in other words, draw the same cross.
Mark on vertical line the position of the upper and lower points of the heart, and on the horizontal the same segment to the left and right of the intersection point.
Connect the top point with a smooth semicircular line to the leftmost point on the horizontal axis and the same smooth semicircular line with the right point.
From the extreme left and right points, lower two smooth symmetrical lines to the bottom edge.

For more experienced artists

The next method of depicting a heart is even simpler; it will help to depict a heart in just a couple of steps and with the effect of rotation around its axis. But this method is only suitable for experienced specialists who can easily draw symmetrical semicircular lines by hand, without using additional constructions.

draw the most ordinary oval, the edges of which are elongated in a horizontal plane.
divide the oval with a line in the middle; if the heart should turn out at an angle, the line should be curved in the desired direction. This frame will show you how to draw a heart step by step and quickly.
select a point just below top point oval on a vertical line and, starting from this position, draw two lines on the upper part of the heart. These lines can completely fit into the oval, or they can protrude beyond its limits, it all depends on your wishes and vision perfect shape for drawing.
repeat the previous point with the bottom of the heart - lower two symmetrical lines to the bottom point.
add Cupid's arrow.

As a result, we get the following picture:

Let's add details

The drawing can be equipped with additional effects, such as wings, horns, halos, inscriptions, fire and similar additions that give additional effects and allow you to harmoniously include the image in one or another motif of the drawing, depending on your ideas. Today we will look at several options for drawing hearts with wings, as the most romantic version of this image. Wings give the hearts a special romanticism and sublime tones. It should be noted that the position of the wings in relation to the heart determines the nature of what the author wants to convey: raised, spread wings show strong intentions, pure feelings, desire for a loved one. On the contrary, the more the wings go down (and possibly connect downwards), the more this shows the heart’s attempt to close itself off from some external factors and problems, an attempt to hide something under its care and care.

Wings on the heart will tell you a lot

So, let's look at how to draw a heart with wings step by step with a pencil. Such a drawing will require you to first study the topic of how to draw a heart or ready-made template with the image of a heart. So, to begin with, we start from the fact that we already have a ready-made drawing. It is clear that the simplest and most uncomplicated way is to draw the wings by hand without any frames or additional constructions. This method may seem to be the most common of the above, but at the same time the most difficult, since it will require the author to have practical skills in drawing symmetrical lines and curvilinear figures by hand. Several options for depicting wings from the heart should be highlighted. Wings can be depicted from the sides or from the top. The position of the wings themselves in this case does not matter at all; what matters is from which part they grow, so to speak.

Wings with feathers in one row

If you decide to depict wings growing from the top of the heart, then it is better to depict them as small, decorative, this gives a certain sophistication and sophistication when in visual contact with the picture. When depicting wings on the sides of the heart, excellent option there will be wings spread to the sides. We do the following:

Chic wings with feathers in several rows

If you want to get a heart effect with huge wings, a span reminiscent of a flying eagle, then it is better to use a multi-level version of the wings rather than a single-level one. The more rows of feathers there are on the wings, the more spectacular the design will seem and the nobler the impulse of the heart itself, as if an eagle’s wings are carrying it towards its lover. So, let's figure out step by step how to draw a heart with wings with a pencil, depicting a rich pattern of feathers or other additional effects on the wings.

As in previous cases, we begin the drawing with the most ordinary frame of the future heart. He can be portrayed as different ways, but it is better to choose one of the above.
To the frame of the heart itself or its finished drawing we add the frame of future wings. There is no need to skimp on space here; the span and size of the wings themselves should be truly royal. Don’t skimp on space; it’s better to draw a smaller heart. Form the frame with several levels at once: the smallest is closest to the heart, the largest is the farthest.

Then start drawing each feather, starting with the smallest at the base and ending with the longest and largest at the edges. In principle, you can start applying layers, gradually depicting each row of feathers separately, superimposing the next one on top of it without a frame. Repeat the steps described with the second wing.

The heart means a lot to a person. A real heart is the basis of our body, and valentines or simple drawn hearts help us express our feelings. This is a manifestation of warmth, love and tender feelings to a person. Below we will give a few simple tips how to draw a heart. There are several drawing options, you can use them or come up with your own.

Simplified version

Before you draw a heart with a pencil (or rather, start), prepare all the tools (paper, eraser, pencils). Place a piece of paper in front of you. First you need to think through the details if you want to add something to the heart. Make sure that all parts of the drawing fit on the sheet. It is better to draw all the main elements schematically (in squares, circles). Now take a pencil and get started. There are three options for how to draw a Valentine heart

First way

Place a dot in the center of the sheet, it will be the base of the heart. Draw a semicircular line, directing it first up to the right and then down. The end point of the arc should be under the base point. You should end up with something that looks like a question mark. Repeat the steps on the left half of the sheet. The lines should converge at one point.

Second way

Draw upside down isosceles triangle(the base should be at the top). Draw a bisector from the bottom vertex. Then “write” half a heart into each of the resulting triangles. Use an eraser to remove unnecessary lines.

Third way

Draw two intersecting circles (you can use stencils) and draw a heart based on them. If it turns out to be asymmetrical, then fold a sheet of paper in half and draw one half at the fold line, then cut it out. Now you know how to draw beautiful heart in its simplified version. When you have the base ready, you can use your imagination: pierce the heart with arrows, thorns, draw roses or wings around it. You can color it or outline it with a marker, leaving it in black and white. Do not overload the drawing with many unnecessary details.

How to draw a human heart

You will also need tools, prepare yourself a space. It is better to use a vertically oriented sheet. In this matter, you need to thoroughly study the anatomy of the human heart. You can copy it from a textbook or medical reference book.

Brief description of the process:

You need to draw an oval that tapers downwards. It should be slightly tilted. Then draw the right atrium. An important part of the heart is the aorta, don’t forget about it. This is a large “tube” that will be located at the top of the picture, with three more vessels coming out of it. Add the veins, don't forget the left atrium. Also trace the drawing and color it if desired. Don't forget to erase extra lines.

Conclusion

Now you know several ways to draw a heart. If you don't get the drawing, don't give up. When everything starts to work out for you, you can please your loved one with a beautiful handmade valentine.

Heart, cor, It is a hollow muscular organ that receives blood from the venous trunks flowing into it and drives the blood into the arterial system. The heart cavity is divided into 4 chambers: 2 atria and 2 ventricles. The left atrium and left ventricle together constitute the left, or arterial, heart according to the properties of the blood in it; the right atrium and right ventricle make up the right, or venous, heart. The contraction of the walls of the heart chambers is called systole. their relaxation - diastole.

The heart has the shape of a somewhat flattened cone. It distinguishes top, apex, base, basis, anterior superior and inferior surfaces and two edges - right and left, separating these surfaces.

Rounded apex of the heart, apex cordis, facing down, forward and to the left, reaching the fifth intercostal space at a distance of 8 - 9 cm to the left of the midline; the apex of the heart is formed entirely by the left ventricle. Base, basis cordis, facing up, back and to the right. It is formed by the atria, and in front by the aorta and pulmonary trunk. In the upper right corner of the quadrangle formed by the atria, there is a place - the entry of the superior vena cava, in the lower - the inferior vena cava; now the entry points of two right pulmonary veins are located to the left, and on the left edge of the base there are two left pulmonary veins. The anterior, or sternocostal, surface of the heart, facies sternocostalis. facing anteriorly, upward and to the left and lies behind the body of the sternum and the cartilages of the ribs from III to VI. The coronary groove, sulcus coronarius, which runs transversely to the longitudinal axis of the heart and separates the atria from the ventricles, the heart is divided into an upper section formed by the atria and a larger lower section formed by the ventricles. Walking on facies sternocostalis anterior longitudinal groove, sulcus interventricularis anterior. passes along the border between the ventricles, and most the anterior surface forms the right ventricle, the smaller - the left.

The lower, or diaphragmatic, surface, facies diaphragmatica, adjacent to the diaphragm, to its tendon center. It goes through posterior longitudinal groove, sulcus interventricularis posterior. which separates the surface of the left ventricle (larger) from the surface of the right (smaller). The anterior and posterior interventricular grooves of the heart with their lower ends merge with each other and form on the right edge of the heart, immediately to the right of the apex of the heart, heart tenderloin, incisura apicis cordis. The edges of the heart, right and left, are of unequal configuration: the right is sharper; the left edge is rounded, more blunt due to the greater thickness of the wall of the left ventricle.

It is believed that the heart is equal in size the fist of the individual concerned. Its average dimensions are: length 12-13 cm, largest diameter 9-10.5 cm, anteroposterior size 6 - 7 cm. The weight of the heart of a man is on average 300 g (1/215 of body weight), of a woman - 220 g (1/250 body weight).

Anatomy of the heart (illustrations, three-dimensional images, photographs of sections)

Images and anatomical links

Human Heart, Anatomy and Physiology

Human heart is a muscle pump that has been baffling people's minds for hundreds of years. In 2725 BC e. In Egypt, Imhotep came to the conclusion that the pulse was related to cardiac function. In 400 BC e. Hippocrates wrote about the heart as a strong muscle.

In 1628 William Harvey published an explanation of the process of blood circulation. Between 1857 and 1882, Marey and Dudgeon, independently of each other, created a machine for measuring blood pressure when hypertension was detected in a person.

IN last years molecular biology helped to discover even more complex functions of this engineering masterpiece - human heart. which confirms the words of the psalmist that you and I are “wonderfully made” (Psalm 139:14).

The term "cardiovascular" describes the heart and blood vessels of the body. Blood vessels are also sometimes called the vascular tree, or bed. In this article we will look at the structure and functions human heart .

The heart is a hollow muscular organ that is located in the central part of the chest, but most of it is to the left of the midline.

A person's heart consists of two upper chambers called atria and two lower chambers called ventricles. Structurally and functionally, the heart is divided into right and left parts; the right side pumps blood to the lungs, the left side pumps blood throughout the body.

The upper chamber, or atrium, collects blood and pumps it into the ventricle, which then expels it from the human heart into large vessels. To ensure blood flows in one direction, each ventricle has inlet and outlet valves.

Left ventricle.

Blood enters the left ventricle from the left atrium through the mitral valve, which consists of two large leaflets that open when the ventricle is relaxed (diastole).

When the filling of the ventricle is completed and it contracts, the force of contraction “presses” the blood to the bottom of the mitral valve leaflets, causing the valve to close. Thanks to this mechanism, blood flows in one direction - from the ventricle to the aorta.

The outlet valve of the left ventricle is called the aortic valve. It has three leaves, or leaflets, that open during contraction of the ventricle, allowing blood to enter the systemic circulation.

As the ventricle relaxes and its pressure drops below the pressure in the aorta, blood begins to flow back (from the aorta into the ventricle).

This reverse flow of blood causes the aortic valve leaflets to fill from above and thus move closer to each other (touching each other) and slam shut. The valve closes and blood does not flow back into the left ventricle.

Right ventricle.

The inlet valve is a tricuspid valve, which by definition consists of three leaflets. It provides one-way blood flow from the right atrium to the right ventricle.

The blood is then released into the pulmonary artery through the pulmonary valve (consists of three leaflets) and flows to the lungs. The tricuspid and pulmonary valves close and open according to the same principles as the mitral and aortic valves, respectively.

The cusps of the mitral and tricuspid valves are attached to the walls of the ventricles by “cords” of tissue and muscle called chordae tendineae and papillary muscles.

These structures keep the valves from opening in reverse side, which would cause the blood to flow in the opposite direction. If these valves, threads or muscles are damaged due to disease processes, then the valves do not close completely and may “leak” (valve insufficiency).

There are also diseases that cause the valves to narrow, which in turn causes a reduction in blood flow through the valves.

As a result human heart The increased resistance is constantly overcome and it increases in size. However, over time, it depletes its reserve of strength and can no longer pump blood as efficiently, which affects the health of the entire body.

The valves can also be affected by both processes at the same time (narrowing and leaking), resulting in weakened cardiac function and impaired circulation.

Cardiac function.

The function of the heart is to pump blood through big circle blood circulation (whole body) and small (pulmonary). Right part The heart pumps blood to the lungs, where carbon dioxide is removed from it and it is saturated with oxygen.

The left side of the heart pumps blood to the rest of the organs; in this way oxygen and nutrients are delivered to them. Waste also enters the bloodstream, but this time through the venous system, so that it is subsequently removed from the body by organs such as the lungs, kidneys and liver.

The contraction and relaxation of the heart is a cardiac cycle that can be felt by feeling the pulsation of blood flowing through the arteries. This can be done by pressing the arteries against the bone, for example in the wrist, lower leg, neck.

Arterial pulsation is created by the build-up of a pressure wave that flows through human arteries from the heart and causes pulsatile expansion of the arterial walls. If we count this pulsation for 60 seconds, we get the pulse rate. In a healthy adult, it is approximately 72 beats per minute (normal range is 65 to 90).

Each cardiac cycle consists of two phases: diastole and systole.

Diastole (or relaxation of the heart muscle) During this phase, the heart muscle relaxes in order to accept a certain volume of flow into the lumen heart, human blood. The atria then contract to move blood into the ventricles.

The next phase is called systole, or ventricular contraction, during which blood is pumped out of the heart. The atria begin to relax in order to accept additional blood to repeat the cycle.

You can not only feel the pulse, but also monitor the cardiac cycle by listening to heart sounds through the chest wall using a stethoscope. These sounds are described as "lub-dub", where the first "lub" sound indicates the closure of the mitral and tricuspid valves, and the second "dub" sound indicates the closure of the aortic and pulmonary valves.

Additional sounds usually indicate some kind of abnormality of the heart valve and/or muscle function. The most common sounds that indicate valve dysfunction are called murmurs.

These sounds are produced when turbulent blood flow occurs due to structural changes in the valve apparatus. Normally, blood flow is smooth, linear and non-turbulent (non-swirling).

Electrical activity of the heart in humans.

In order for the heart to beat in an orderly manner, it is equipped with nerve pacemakers (a collection of nerve cells in the atria) and a special conduction system that delivers nerve impulses to the heart muscle.

Different parts of the conduction system and even parts of the heart itself are capable of beating at different rates. The conduction system provides sequential, coordinated activation from the atria to the ventricles.

This electrical system ensures that impulses reach all parts of the heart muscle. The electrical axis of the heart is determined using electrocardiogram (ECG) data.