Heart (Latin: cor, Greece: καρδια – chard) is a muscle that is constantly pumped (pumping) blood to the cells of your body. Thus the supplies life essential oxygen and nutrients. The heart is divided into four sections: the left atrium, left ventricle, right atrium and right ventricle.
The heart works like a mechanical pump and an electrical organ at the same time. Electrical pathways of the heart undergoing pulses causing contractions of the cardiac muscle, thereby pumping blood through the body.
In mammals, the heart is placed in the chest between the lungs, breastbone (sternum axis) and the diaphragm. Externally it is covered by a fibrous sheath called the pericardium (pericardium).Inside the pericardium is a thin double membrane. In this narrow double bag is pericardial space filled with a small amount of fluid (liquor pericardii) which protects the heart from friction and impact.
Heart wall consists of three layers:
The walls of the atrial muscle have less than the chamber walls because their smaller activities. It is most massive muscle of the left ventricle, which pumps blood into the systemic circulation.
Anatomy of the human heart
Anterior (front) view of open human hearts. White arrows indicate normal blood flow.
The heart of man is saved in medzipľúcí (mediastinum). It has the shape of a cone whose base is oriented upwards. Heart tip directed forward and down. Approximately 2/3 of the heart is stored in the third left and right chest. The heart of an adult weighs an average of 300 g for men and 250 g for women. The length from the base after the tip is on average about 12 cm.
The chest wall to the heart is reflected in the area that can circumscribe the four points (A – D):
Heart mammals are four chambers, which means that is internally divided into four separate, functionally differentiated parts:
Left and right side of the heart (ie. Left and right heart) cardiac compartments are separated
Between the hall and the appropriate chamber located valve leaflets that separate the hall from the chamber and act as one-way valves, that allow blood to flow only in the direction from the respective hall into the chamber. At the heart of the chip are two tabs:
The valve leaflets are actually pouches endocardium. Their function is securing the direct blood flow from the atria into the ventricles. When the hall is filled, increasing the pressure in them blood, causing the leaflets of the valve to deflect toward the chamber, thereby moving away from each other. In this way the flap opens and the blood flows from the atria into the ventricles. After the outflow of blood from the atria to the ventricles pressure drops in the hallways and the flaps close again. So that after the closure flaps nevychlípili antechambers (upward), are fastened with mastoid muscles, which is pulled toward the chamber (downwards). Opening and closing valves is passive, is controlled by pressure changes in the atria and ventricles. Mastoid muscles (musculi papilares) Thus, the valve does not open or close properly, just keep the leaflets of the valve in position when closed.
Heart valves are between the chamber and the outlet into the appropriate artery. These are known as semilunar (half-moon). They are:
If the valves do not open enough and their mouth is narrow (eg. Because the chips are partially fused), we are talking about valve stenosis.Conversely, if the overflow valve after the blood sufficiently left open, because the chips are not adjacent to each other, there is a backflow of blood, and this status indicates failure, valve insufficiency. The most common causes damage to the valves in the heart of rheumatic fever and endocarditis. Severe valvular mistakes can lead ultimately to heart failure. The solution may be a surgical solution, which involves the reconstruction (sculpture) or replacement of the damaged valve.
cardiac skeleton
Support form the fibrous skeleton of the heart – cardiac skeleton. In humans, it forms a solid collagen and elastic tissue that separates the muscles of the ventricles and atria and creates fibrous ring around the valve. Connective tissue forms a support heart valves. For some animals (dog, rabbit) is a cardiac skeleton consists cartilagenous deer and even bones.
Blood supply to the heart ensure coronary (coronary) arteries (arteriae coronariae) that extend directly from the aorta. Coronary arteries carry oxygen and nutrients to individual cells of the myocardium. Deoxygenated blood is then removed from the heart cardiac veins (vena cordis), in which the coronary sinus (coronary sinus). Coronary sinus is lived, which opens into the right atrium.
The total amount of blood in the body of an adult is 5-7 liters. Large blood loss is life threatening. Blood loss during major losses, such as surgery, trauma, replacing blood transfusions or transfer.
Description hypertension Hypertension or high blood pressure, is one of the commonest cardiovascular diseases. This disease is nowadays mass market.According to statistics, the hypertension treated about 20% of adults. Although this number is already quite high and does not include…
Description heart failure Heart failure occurs on average about 2% of the population. Incidence rises from a low occurrence at a young age after values of over 10% in advanced age. To understand the subject is required at least a…
Description pericarditis Introduction to the issue Pericardium or pericardium is a membrane that consists of two sheets, which is closed to form a tapered bag which urges the specific area of the diaphragm (center tendineum). Within this pouch is found…
Description of low blood pressure Hypotension in principle, not a disease. Either it is a manifestation of the disease, or simply a manifestation of one’s body. About hypotension, or low blood pressure, we speak when measured systolic blood pressure (it…
Description myocarditis It is an inflammatory disease of the heart muscle (myocardium), which most often caused by viruses. Speeches are very varied, from almost nepovšimnutelných to heavy, torrential, leading to death. It is interesting that this disease is one of…
Description of aortic coarctation Coarctation of the aorta among the congenital malformations of the heart and great vessels. This is a narrowing of the aorta,the main artery leaving the heart that allows blood nourishing the whole organism. The constriction may…
Description of myocardial infarction Acute myocardial infarction (AMI) is one of acute forms ofischemic heart disease. Generally we can say that coronary artery disease is a disease in which there is a blockage of a blood vessel clot – thrombus,…
Description hypertrophic cardiomyopathy In the beginning it is necessary to clarify and define the term cardiomyopathy. Cardiomyopathy is defined as a primary disease of the heart muscle (hereinafter referred to as the myocardium), which are guided primarily impaired cardiac function….
Description atrial septal defect and ventricular It is a congenital heart defect ventricular or atrial septum, which is created by communication between the right and left side of the heart and leads to mixing of deoxygenated blood from the right…
Description arrhythmia The cardiac muscle cells are groups which have a different role than all of cardiac muscle cells.Formed in them repeatedly impulses that spreads to other cells to spread throughout the heart and thus leads to repeated contractions of…