The left atrial groove is the left atrium, with four pulmonary veins pouring in. The left atrium is related to the oesophagus in the back, so when the left atrium is large, it will press on the oesophagus.
The heart is a hollow muscle mass that acts like a pump to both suck and push blood away; consists of two halves right and left. Each half of the heart has two chambers: one that receives blood from a vein called the atria, and another that pushes blood into the arteries called the ventricles.
The heart is in the mediastinum, shifted to the left side of the thorax, pressing on the diaphragm, between the lungs, the anterior esophagus and other components of the posterior mediastinum. The heart axis goes from the back to the front, pointing to the left and down.
The heart has a pyramid shape of 3 faces, a base and a top. Bottom is above, facing back and slightly right. Peak is ahead, left side.
The base of the heart corresponds to the posterior atrium with the atrial furrow in the middle.
To the right of the atrial groove is the right atrium, associated with the right pleura and right diaphragmatic nerve, with the upper and lower aorta with the inferior vena cava pour in.
To the left of the atrial furrow is the left atrium, with four pulmonary veins that enter. The left atrium is related to the oesophagus in the back, so when the left atrium is large it will press on the esophagus.
Also known as the front has:
The coronary groove runs horizontally above, separating the upper atrium from the lower ventricle.
The atrial part is covered by the pulmonary artery stem and the aorta. The two sides have two right and left atriums.
The ventricular part has anterior ventricular furrow running from posterior to anterior, shifting to the right of the apex, separating the right and left ventricles. The right ventricle covers most of this face.
Or the lower face, presses on the diaphragm and across the diaphragm associated with the left lobe of the liver and bases.
The coronary groove in the sternum runs down the diaphragm, dividing the heart into two parts: the posterior part is the atrium, slightly narrow, the anterior part is the ventricle, wider, has a posterior ventricular groove, runs from posterior to anterior and connects with the anterior ventricular furrow to the right of the apex.
Also known as the left side: narrow, associated with the left lung and pleura, left diaphragmatic nerve.
Also known as the crown of the heart, lying sideways to the left; just behind the thoracic wall, corresponding to the space of the V-rib on the midline of the left collarbone
Figure. The rib cage of the heart
- Right atrial groove 2. Coronary groove 3. Aortic arch 4. Pulmonary artery body 5. Anterior ventricular fissure 6. Left atrium
The walls of the heart
The heart is divided into chambers by the heart septum.
Atrial Septum: dividing the atrium in two; thin, corresponding to the outer atrial space. During the embryonic period, the atrial septum has an opening to allow blood to travel from the right atrium to the left atrium. After birth, usually closed. If not closed: there is a hole called an oval hole, causing the atrial septal defect.
Ventricular septum: the separation between the two ventricles, corresponding to the outer ventricular furrows.
Atrial septum: A thin membrane separating the right atrium from the left ventricle. This is due to the fact that the left ventricle is larger than the right ventricle, causing the membrane part of the interventricular septum to shift to the right.
The atria have thinner walls than the ventricles. They receive blood from the veins. Each atrium connects with an atrium at the top and connects to the same ventricle through the atrioventricular hole. The atrium must receive blood from the superior vena cava, the inferior vena cava, and the coronary sinuses. The left atrium receives blood from the pulmonary veins.
The ventricles have thicker walls than the atrial wall, which connect with the atrium on the same side and produce large arteries.
Right ventricle: shaped like a pyramid of three sides, with the right atrioventricular hole opening between the right atrium and the right ventricle, which is covered by the right atrioventricular valve or the tricuspid valve.
Anterior above the right atrioventricular hole is the pulmonary stem hole, covered by the pulmonary stem valve consisting of three bird's nest-shaped valves.
Left ventricle: cone flattened, with two walls. The left ventricle is connected to the left atrium with the left atrial hole with a mitral valve in this hole that does not allow blood from the left ventricle to flow back to the left atrium. There is also an aortic opening with a closed aortic valve. The aortic valve is structurally similar to the pulmonary stem valve.
Figure. The inner shape of the heart
- The diaphragm of the interventricular septum 2. The muscular part of the ventricular septum 3. The mitral Val 4. The tendon 5. The muscle column
Anatomy of the heart
The heart is composed of three layers
Or the pericardium, which is a closed serosa, limits the mediastinum. Consists of two layers: outer fibre wrap. called the fibrous pericardium, and the inner lining of the serosa called the serosa. Pericardium serosa consists of two leaves: leaves lining the inner surface of the fibrous envelope and visceral leaves covering the heart's surface. The leaves are contiguous and between the leaves is a virtual cavity called the pericardial cavity.
Cardiac muscle consists of two types:
The muscle fibres contract: predominantly, attaching to the four fibres around the heart's four large holes, the two atrioventricular and two artery holes.
Poorly differentiated muscle fibres: create the conduction system of the heart, responsible for maintaining the automatic contraction of the heart. This system consists of a number of nodes, the following bundle: the sinoatrial node in the right atrial wall, is the pacemaker node; the AV node in the inner right atrial wall; the atrioventricular bundle starts from the atrioventricular node, runs on the right side of the atrioventricular septum, to the muscular part of the ventricular septum. The atrioventricular bundle is divided into two pillars, the right and left column running into the ventricles.
Or the lining of the heart, thin, shiny; covering and adhering to the surface of the heart chambers, in contact with the endothelium of blood vessels.
The blood vessels and nerves of the heart
The heart is fed by the right coronary artery and the left coronary artery. The two arteries are usually connected but not connected to neighbouring arteries.
Right coronary artery: separating from the aortic head up, following the coronary groove running down the diaphragm surface of the heart, for the posterior ventricular branch, then continuing to the left, possibly connecting with the exponential branch of the left coronary artery. The right coronary artery supplies blood to the right half of the heart and part of the left ventricle.
Left coronary artery: from the aorta through the gap between the pulmonary artery stem and the left atrium to anterior, dividing the two branches of the anterior ventricular branch going in the anterior ventricular fissure to the apical defect, connecting with the posterior ventricular branch. of the right coronary artery and the coronary branch to the coronary groove down the diaphragm surface and may connect to the right coronary artery.
Veins of the heart
The veins consist of the large cardiac vein that follows the anterior ventricular branch in the anterior ventricular furrow, the medial vein going in the posterior ventricular furrow, the posterior ventricular branch, the posterior vein of the left ventricle, the serosa of the left atrium, small heart veins ...
Figure. Blood vessels of the heart
- Transverse sinus 2. Right coronary artery 3. Left coronary artery 4. Coronary artery 5. Anterior ventricular artery
The nerve of the heart
In addition to the automatic conduction system, the heart is also dominated by sympathetic fibres from the neck and upper thoracic lymph nodes, sympathetic fibres from the wandering nerve (X nerve).