What does the human heart look like?
Author Ольга Кияница
The human heart is a hollow body, mainly consisting of muscle fibers. Large vessels in the form of veins, through which blood flows into the heart cavity, are suitable for it. After a regular cut through the aorta, blood is released into the bloodstream. Such a closed cycle is observed throughout the period of human existence.
Normally, in an adult, the heart is reduced from 60 to 90 beats per minute. With physical training or excitement, the heartbeat increases, while during sleep or rest, the heart rate decreases.
Studying the appearance of the heart is directly related to the organ's anatomy. For three centuries, various studies have been conducted that allowed us to explore many of the features of this amazing body. Both inside and outside the human heart looks very interesting and well thought out, so it is worth taking time and finding out about this body unusual details.
Video Anatomy of the Man - Heart
Appearance of the heart in the fetus
The appearance of the heart depends a lot on the period of human development. For example, at the very beginning of the fetal development, the heart looks like a tube, which in principle resembles a blood vessel. In the course of the development of the embryo, the walls of this formation thicken, as muscle fibers begin to actively form, which are further included in the structure of the myocardium. At the same time the heart of the fetus appears to be reduced.
The first contractile activity of the heart tube is observed on the 22nd day after conception. At first, it is weak, but gradually the strength of the contractions increases and after a couple of days the embryo begins to circulate blood through blood vessels. Thus, on the 28th day from the onset of development of the fetus, a primitive blood supply system is observed.
The proper laying of the heart during the development of the fetus helps to avoid many congenital diseases of this organ. That is why it is extremely important in the first months of pregnancy to avoid various nervous shocks, physical stresses, harmful effects of alcohol, smoking, drugs, infections, which often lead to various cardiac pathologies.
What does an adult look like?
At an external examination of the formed and fully developed human heart, an expanded part, or a base, and a narrowed, or top, is immediately observed. The edges of the heart also differ from one another: the left is more blunt, and the right is vice versa, pointed. The furrows located on the surface of the heart point to the boundaries inside the cavities. The furrows themselves are often covered with fatty fiber, which in pathological cases (in obesity or fatness) is determined throughout the muscle of the organ, which does not allow him to work properly.
In the normal state, the weight of the heart is on average from 250 to 350 g. In this case, the length of the organ is equated to an average of 12-13 cm, width - to 9-10 cm, and the transverse dimension - to 6-7 cm.
The heart is located and its whole life is reduced in an ozoloserdechnoy bag - pericardium. His role is to guard the heart from other organs. Also, in a pericardial bag there is a certain volume of fluid, which in the normal state performs the role of "lubricant", which allows the heart to smoothly work.
In the thorax, the heart is placed asymmetrically, so it looks like this: 2/3 of the body from the center line is to the left, and 1/3 to the right. Also, with respect to longitudinal projection, the heart may have different positions: horizontal, vertical, and oblique.
Video How the human heart works
The anterior part of the heart mainly refers to the right ventricle, in comparison with which the left ventricle is directed backwards. Also, the right atrium is determined in the front and the adnexa cavity, called the ear, which covers the ascending part of the aorta, is especially noticeable. In the front, the left atrium is practically imperceptible, with the smaller size of the ear more in contact with the pulmonary trunk.
Heart from inside
The longitudinal section of the body provides an opportunity to see its structure from the inside. The main components of the heart are chambers or cavities, for separation there are partitions. Each portion of the blood comes from or comes from certain vessels:
- the blood from the hollow veins is directed to the right atrium;
- pulmonary veins approach to the left atrium;
- Arterial blood from the right ventricle passes through the pulmonary trunk (small circle of blood circulation);
- from the left ventricle the blood passes into the aorta (a large circle of blood circulation begins).
In this way, it turns out that the small circle of blood circulation starts from the right ventricle and ends with the left atrium. The large circle of blood circulation, respectively, begins with the left ventricle and ends with the right atrium.
In addition to the heart chambers on the longitudinal section, valves are visible which are necessary to ensure normal blood flow. These structures of the heart are opened only in one direction, and, as a rule, blood should not pass between the openings. For the exact distinction, each valve has its own name:
- mitral - has two flaps and is defined between the atrium and the ventricle on the left side;
- three-winged - is three-winged and located on the border between the atrium and the ventricle on the right side;
- Pulmonary valve - controls the flow of blood from the right ventricle in the pulmonary trunk;
- aortic valve - regulates the blood flow from the left ventricle to the aorta.
Around the heart there are coronary arteries, which provide coronary blood supply. They look like a crown, so they got a name like "crown arteries."
Unusual facts about the heart
- The frequency of heart contractions in a fetus is several times greater than that of an adult and is approximately 140 beats per minute, and after 10 weeks the volume of circulating blood equals to 60 l / day.
- Adult heart rate is approximately 72 times / day, so over 2 million heart rate is defined in approximately 65 years.
- The total length of all blood vessels is more than 120 million meters, which allows three times to circumvent the Earth along the equator.
- On the adipose tissue, blood vessels also pass and in case of obesity the heart has to pump blood over vessels of length more than 8 thousand. kilometers
- One cycle of blood supply lasts about 23 seconds and approximately the same amount is needed for a person to run 200 meters.
- In one cubic milliliter of blood, about 5.5 million red blood cells, which are also called red blood cells, are detected. It takes 120 days to complete their update.
- Diseases of the heart are the most common cause of human death. It has been proved that cardiovascular diseases have claimed more lives than all wars in the history of mankind.
Video of 10 unknown facts about the human heart. I Vam Nauka
The presence of diseases of the coronary vessels may suggest the performance of such an operation as heart bypass. With its help, the normal blood supply to the myocardium is restored, which reduces the risk of developing a heart attack. There are various indications and contraindications for this surgery.
In diagnostics of cardiovascular diseases an important role is played by timely diagnostics. It is often enough to conduct a standard ECG to make a correct diagnosis. In other cases, a diverse study of the heart is required, which allows you to establish the exact cause of the illness and conduct an effective treatment.
The development of heart failure is mainly accompanied by the appearance of a symptom such as shortness of breath. Depending on its severity, the patient's condition may be disturbed to a greater or lesser extent. The occurrence of shortness of breath often indicates the progression of the underlying disease and the need for emergency medical treatment.