Cardiac Anatomy and Physiology

Cardiac Anatomy and Physiology

The heart is about one fist and is located in the chest, right hand boundary at exactly the right sternum and fifth intercostalis apeksnya on the space left on the mid clavicular linea. The upper limit of heart there is a large blood vessels (aorta, pulmonary truncus, etc.); the bottom of the diaphragm; the rear boundary there descendens aorta, esophagus, and columna vertebral; while on each side of the heart is the lung.
Right Atrium
The right atrium is on the right side of the heart and located mostly behind the sternum. Blood enters the right atrium via:
o Vena cava superior to the upper end
o Vena cava inferior at the lower end
o Sinus coronarius (small veins that drain blood from the heart itself)
Auricula dextra is a small sharp protrusion of the atrium, located on the front of the base of the aorta and pulmonary artery. On the left side of the atrium of the right atrioventricular opening hole into the right ventricle.
Right ventricular
Right ventricle is a thick-walled spaces that make up most of the front side of the heart. Valva dextra atrioventricular (tricuspidalis) around the right atrioventricular opening, on the side of the ventricle. This valve, like the other cardiac valves, formed of a thin layer of fibrous tissue covered on each side by the endocardium. Trikuspidalis valve consists of three cusps. Base of each leaf valve attached to the edge of the hole. The free edge of each leaf valve attached to the chordae tendineae (connective tissue thin straps) on a small protrusion of the muscle tissue that comes out of the myocardium and protrude into the ventricles. Pulmonary holes into the pulmonary artery is at the upper end of the ventricle and is surrounded by valva pulmonary valve leaflets consist of three semilunaris.

Left Atrium
Left atrium is a thin-walled space that lies at the heart berlakang. Two pulmonary veins entering the left atrium on each side, carrying blood from the lungs. Atrium opening down into the left ventricle through the atrioventricular opening. Auricula sinistra is a small sharp protrusion of the atrium, located on the left side of the base of the aorta.
Left ventricular
The left ventricle is a thick-walled room on the left and behind the heart. The walls are about three times thicker than the right ventricle. Valva sinistra atrioventricular (mitralis) around the left atrioventricular hole on the side of the ventricle, this valve has two cusps have the same name with a hat (miter bishop), the edges attached to the chordae tendineae, which is attached to the protrusion cone ventricular wall myocardium. Aortic opening holes of the upper end of the ventricle into the aorta and surrounded by the three leaves of the aortic valve, together with the pulmonary valve.
Myocardium
Myocardium to form the largest part of the heart wall. Myocardium is composed of fibers - the heart muscle fibers, which are striated and relate to each other by branch - the branch muscular. Fibers begin to contract in the embryo before neural achieve it, and continue to contract rhythmically even if they do not get innervation.
Endocardium
Endocardium lining the inner cavity of the heart and the valve cover on both sides. Consisting of a layer of endothelial cells, underneath there is a layer of connective tissue, smooth and shiny.
Pericardium
Fibrous pericardium is the bag that covers the entire heart. Pericardium is a two-layered bag, the two layers of sliding contact with each other and mutually help each other with their liquid sekresikan and moisturize the surface. The amount of fluid that is normally around 20 ml. At the base of the heart (where the large blood vessels, lymphatics, and nerves entering the heart) both layers continues. There is a layer of fat between the myocardium and pericardium in the upper layers.
Arteria coronaria
Second arteria coronaria, right and left, supplying blood to the heart wall. The artery out of the aorta just above the aortic valve and running down each - one on the right and left side surfaces of the heart, giving to branch into the myocardium. These arteries supply each - each side of the heart but have individual variations and in some people, arteria coronaria dextra supplying most of the left ventricle. The artery has relatively few anastomoses between the artery and left dextra.
Cardiac Cycle
Cardiac cycle is a sequence of events in one heartbeat. This cycle occurs in two phases, namely:
  diastoleØ
Diastole is the period of rest which followed a period of contraction. In the beginning:
1. Venous blood entering the right atrium through the superior and inferior vena cava.
2. Oxygenated blood through the left atrium through the pulmonary vein.
3. Both valves atrioventikular (tricuspidalis and mitralis) closed and blood prevented from entering the atrium into the ventricle.
4. Pulmonary and aortic valve closed, preventing blood kembalinnya from the pulmonary artery into the right ventricle and the aorta into the left ventricle.
5. With the increased amount of blood entering the two atria, the pressure in it increases and when the pressure inside is greater than the ventricles, the AV valves open and blood began to flow from the atria to the ventricles.
  systoleØ
Systole is the period of muscle contraction, lasts 0.3 seconds.
1. Stimulated by the sino-atrial node, atrium walls to contract, squeezing the remaining blood from the atria to the ventricles.
2. Ventricles dilate to receive blood from the atria and then begin to contract.
3. When the pressure in the ventricles exceeds the pressure in the atrium, AV valve closes, preventing the valve chordae tendineae pushed into the atrium.
4. Teruss ventricular contraction. Pulmonary and aortic valve opening due to increased pressure.
5. Blood gushed out of the right ventricle into the pulmonary artery and the blood gushed from the left ventricle into the aorta.
6. Muscle contractions then stopped and the beginning of muscle relaxation, a new cycle begins.
Each contraction was followed a short absolute refractory period when no stimulus that can produce a contraction, and followed a relatively short refractory period during contraction requires a strong stimulus.
Heartbeat
Sino-atrial node (SA nodua or cardiac pacemaker) is a small area of ​​muscle fibers and nerve cells located in the heart wall near the entrance superior vena cava. At first systole, the contraction wave starting at this node and spread through the walls of the two atria, stimulates the atria to contract, the contraction of the atria to the ventricles does not spread because it can not through a ring of connective tissue separating the atria from the ventricles, reaches and stimulates the lymph atrioventrikularis.
Atrioventrikularis node (AV node) is a small area of ​​specialized tissue in the wall between the right atrium and right ventricle. File atrioventrikularis (bundle of His) is a ribbon of muscle and nerve fibers that run on the septum between the ventricles, reaching the apex of the heart and is divided into two main branches, one for each ventricle which is divided into several smaller branches within the ventricular wall. Contraction wave spreads from the AV node down to the AV file and sets off contractions of both ventricles simultaneously. Waves of contraction that began in the SA node causes the atria to contract just before the ventricles due to waves and waves soon reach the atrium into the ventricle must pass through the AV file.
Rainfall Heart
Cardiac output depends on:
  frequency heart ratev
When a break is usually about 70 times per minute. Heart rate is controlled mainly by a reduction in the stimulation via the parasympathetic nerve fibers (vagus), a smaller effect by stimulation through sympathetic nerve fibers.
 vRainfall sekuncup  
Sekuncup rainfall is the amount of blood that comes out of the ventricle at each beat. When a break is usually about 70 ml. In mild exercise increased to 125 ml. At the beginning of ventricular contraction, with the body in a resting state contains about 120 ml. About 50 ml from the left ventricle at each beat.
Sekuncup bulk fiber length is controlled by changes in heart muscle. The longer (on the wrong muscle) the greater the contraction. As more blood enters the heart (as in exercise), the greater the contraction and thus the greater the bulk sekuncup.
Cardiac output was measured by measuring the amount of oxygen taken up by the lungs per minute, and various dilution techniques with dyes, radioactive isotopes, etc..