Inside of The Human Heart
1. Tashimbetova Umut Kapaeovna
2. Mohamed Kasim
(1. Lecturer, International Medical Faculty, Osh State University, Osh, Kyrgyz Republic.
2. Student, International Medical Faculty, Osh State University, Osh, Kyrgyz Republic.)
The heart is a special muscle that pumps blood through our body. It is the part of the system that circulates blood, which is necessary for our body to work properly. The heart is located in the middle of our chest. It is surrounded by a special sac called the pericardium. This sac protects the heart. Helps it move smoothly. There are also some spaces around the heart called the pericardial sinuses. These spaces are formed by the sac that surrounds the heart and are very important for doctors to know about when they're doing heart surgery on the heart. The heart is an organ and the pericardial sinuses play a big role in heart procedures, on the heart. The heart looks really neat from the outside. It has surfaces and borders. You can easily see the apex and the base of the heart. This helps figure out how the heart is positioned and how it fits with things in the chest. When you look inside the heart you will see that it is divided into four parts. These are the right and left atria and the right and left ventricles. Each of these parts is special. Does its own job.
The atria are like the waiting rooms of the heart. They get the blood first. The ventricles are, like the pumps. They push the blood out. The left ventricle is really strong because it has to push blood around the body. It has a layer of muscle that helps it do this job. The heart beats in a rhythm because it has a special system that helps it work properly. This system is made up of fibers in the heart muscle. The heart muscle gets the blood it needs from the arteries. These arteries are very important for the heart to work right. To understand how the heart works when it is sick you need to know how it is supposed to look and work normally. This is especially important for things like heart disease problems with the heart valves, problems with the heartbeat and heart problems that people are born with. The heart is an important part of our body and we need to know about cardiac anatomy to understand these clinical conditions, like ischemic heart disease, valvular abnormalities, conduction defects and congenital cardiac anomalies.
KEY WORDS:
Heart-Pericardium-Atria-Ventricles-Cardiac Conduction System-Coronary Arteries Hypertension-Coronary Artery Disease (CAD)-Angina-Heart Failure
HISTORY:
Willem Einthoven invented the electrocardiograph. This was a deal for cardiology. He even got the Nobel Prize in Physiology or Medicine in 1924. The electrocardiograph helped doctors record what the heart is doing electrically. The first time someone tried to transplant a heart into a person was in 1964. James Hardy did this. He used a chimpanzee heart. The patient did not live long, only two hours. Then something big happened in 1967. Christiaan Barnard did the successful heart transplant from one human to another. He did this at Groote Schuur Hospital in South Africa. This was a milestone for heart transplants. The heart transplant was a success. The early results of heart transplants were not very good with the person to get one, Louis Washkansky, living for only 18 days.. Then doctors like Norman Shumway, Richard Lower and Vladimir made some important discoveries. They helped make heart transplants better and more people were able to survive for a time after getting a new heart. The work of these doctors, including Norman Shumway, Richard Lower and Vladimir was very important, for heart transplants. Demikhov and Adrian Kantrowitz made changes to heart transplant techniques. Heart transplants have become pretty common. By the year 2000 doctors had already done over 55,000 heart transplants around the world. In the year 2022 Bartley P. Griffith did something new. He transplanted a genetically modified pig heart into a human being and the person lived for almost two months. Heart disease is still the number one cause of death. The Framingham Heart Study and other studies like it have helped us understand what puts people at risk for heart disease. We have some treatments now like ACE inhibitors and beta-blockers that help people with heart disease feel better. With these treatments heart failure is still very serious and can be fatal. Heart disease and heart failure are still problems that doctors are trying to solve.
INTRODUCTION:
The human heart is an important muscle that pumps blood through our body. It keeps the blood moving all the time making sure our body gets the oxygen and food it needs. The heart gets rid of the bad stuff our body does not need. The heart is in the middle of our chest. It has a special covering called the pericardium that helps it move smoothly. The human heart has four parts: two parts that get blood and two parts that send blood out. This helps the human heart do its job of sending blood to our lungs and the rest of our body. The human heart needs to work so we can stay alive and our body can work the way it should. The human heart is very important for our health.
PERICARDIUM:
The heart is surrounded by the pericardium. The pericardium is like a sac. It is made of material. This sac encloses the heart and the roots of the vessels that are connected to the heart. The pericardium is very important for the heart. The vessels are surrounded by the heart on all sides except at the root, where the great vessels enter and leave the heart and at the bottom, where only the serous pericardium covers the top surface of the central tendon of the diaphragm. The pericardium is made up of two parts: the outer fibrous layer and the inner double-layered serous membrane of the pericardium. The fibrous pericardium is, like a -rigid shield that protects the heart whereas the serous pericardium is a thin and smooth layer that is very flexible. The pericardium and the vessels work together to keep the heart safe. The serous pericardium is made up of a membrane that covers the inside of the fibrous pericardium. This membrane is called the layer. It then folds back to cover the heart. This part is called the visceral layer or the epicardium. The serous pericardium has these two layers. Between the two layers of the pericardium there is a space called the pericardial cavity. This space has an amount of fluid in it about 15 to 50 milliliters. The fluid in the cavity helps the heart move smoothly and protects the heart from getting hurt. The fibrous pericardium is made up of tissue and it helps decide the size of the middle mediastinum. The fibrous pericardium and the serous pericardium work together to keep the heart safe. The heart is attached well to the central tendon of the diaphragm by the pericardiacophrenic ligament at the bottom. At the top the heart is connected to the tunica adventitia of the blood vessels. In the front the heart is tied to the sternum by ligaments. At the back the heart is close to the things in the mediastinum. These attachments keep the heart steady, stop it from getting too big and keep it in the place inside the chest. The serous pericardium wraps around the roots of the blood vessels making the transverse and The pericardium has these things called pericardial sinuses. These sinuses are really important for surgeons and people who look at radiology pictures. The pericardium is located inside the chest behind the sternum and the front of the chest wall. The phrenic nerves go down along the sides of the pericardium. The pericardium gets its blood supply from the artery. It also gets some blood from the artery, the bronchial artery, the esophageal artery and the superior phrenic artery. The pericardiacophrenic veins and the azygos system help get the blood out of the pericardium. The phrenic nerves also help the pericardium feel things. That is why people with diseases sometimes feel pain in their shoulders. The pericardium and its sinuses, like the pericardial sinuses, are important to understand.
PERICARDIAL SINUSES:
The heart has these spaces called pericardial sinuses. They are like pockets that form when the serous pericardium folds around the blood vessels that come out of the heart. Pericardial sinuses develop when the heart is forming and they stay there as landmarks that doctors can see. Pericardial sinuses are important because they let the heart move around freely. They also give doctors a way to get to the heart when they need to do surgery on it. The pericardial sinuses are like roads that doctors can use to get to the heart.
Transverse Pericardial Sinus
The transverse pericardial sinus is like a tunnel. It is behind the ascending aorta and pulmonary trunk. It is also in front of the vena cava and the top part of the left atrium. The transverse pericardial sinus connects the right and left parts of the cavity. This transverse pericardial sinus is very important for surgeons. They can put a finger or a clamp or a ligature through the transverse sinus. This helps them to go around the ascending aorta and pulmonary trunk. It stops the blood from flowing out of the arteries for a while. This is useful when doctors are doing things, like artery bypass grafting and open-heart surgery on the transverse pericardial sinus and the heart.
Oblique Pericardial Sinus
The oblique pericardial sinus is a space that is shaped like an upside down J. It is located behind the atrium. The oblique pericardial sinus is made when the serous pericardium folds around the veins and the inferior vena cava. The oblique pericardial sinus gives the atrium room to get bigger when the heart is filling with blood. You can see the pericardial sinus on pictures from imaging tests. The oblique pericardial sinus is important for doctors to know about when they look at these pictures. This is because fluid can collect in the pericardial sinus and it might look like there is something wrong with the tissue, behind the heart.
Superior Pericardial Sinus
The superior pericardial sinus is a space that is found in front of the ascending aorta and the pulmonary trunk. This space is not as important for procedures. Doctors usually do not look at the pericardial sinus when they are doing tests or surgery. However the superior pericardial sinus can be seen on pictures taken with machines. It is a part of the body. The superior pericardial sinus is a small area that is usually not a problem.
EXTERNAL STRUCTURE OF HEART:
The human heart is located in the middle of the chest inside the thoracic cavity. It goes from the thoracic vertebra to the eighth thoracic vertebra. The human heart is covered by a sac called the pericardium. This sac is like a bag that holds the heart in place so it does not move around too much but it still allows the human heart to move a little bit when it beats. The human heart is close to the spine in the back. In the front the human heart is, near the breastbone and the ribs. The top part of the heart is called the base. This is where the big blood vessels are connected, like the venae cavae, ascending aorta and pulmonary trunk. The base of the heart is around the costal cartilage. The bottom part of the heart is called the apex. This part is made up of the ventricle and it points down forward and to the left. You can usually find the apex of the heart in the fifth intercostal space near the mid-clavicular line. The heart is an important organ and the apex and base of the heart are two of its main parts. The hearts base and apex work together to keep the heart beating. The heart is usually a bit to the left of the middle of our body. This is what normally happens.. Sometimes the heart is on the right side of our chest. This is called dextrocardia. It is very rare. The heart is usually on the side, which is called levocardia. Because the heart is on the side the left lung is smaller than the right lung. The left lung also has a shape. It has a little notch in it and this notch is because of the heart. The heart is shaped like a cone on the outside. It has some marks on it called grooves or sulci that show where the different parts of the heart are. The coronary sulcus is a groove that goes all the way around the heart. It separates the atria from the ventricles. This groove has some important blood vessels in it. There are two grooves, one in the front and one in the back that are between the ventricles. These grooves show where the interventricular septum is. The interventricular septum is a wall that separates the ventricles. These grooves also have branches of the arteries and veins in them. These marks on the heart are very important because they help us figure out what is inside the heart. The heart has these surface landmarks that make it easier to identify the anatomy of the heart. The heart in adults is pretty heavy; it weighs around 250 to 350 grams. It is also a size, about 12 centimeters long, 8 centimeters wide and 6 centimeters thick. The heart can get a little bigger in athletes who exercise a lot. This is because the heart muscle gets stronger, which is a thing for the heart. The heart gets bigger because of something called myocardial hypertrophy that happens in well trained athletes.
INTERNAL STRUCTURE OF THE RIGHT ATRIUM:
The heart has a part called the atrium. This is where the heart gets blood that does not have oxygen. This blood comes from around the body through big veins like the superior and inferior venae cavae. It also comes through veins like the coronary sinus, anterior cardiac veins and smallest cardiac veins.Inside the atrium there are two different areas. These areas are separated by a special muscle part called the crista terminalis. The back part of the atrium is smooth. This part is called the sinus venarum. It is around the openings of the veins like the vena cava and the coronary sinus. The sinus venarum is like a leftover part, from when the heart was forming. The heart has a part called the embryonic sinus venosus. The sinoatrial node, which is the pacemaker of the heart, is found near the top of the crista terminalis close to the superior vena cava. The sinoatrial node is very important for the heart. In the heart the anterior wall and the right atrial appendage also known as the auricle are rough. This is because of the musculi pectinati, which are comb-like ridges. These ridges help the heart contract. There is also a depression in the septum called the fossa ovalis. The fossa ovalis is what is left of the foramen ovale. It has a raised edge, which is called the limbus. The heart and the sinoatrial node and the fossa ovalis all work. The triangle of Koch is an area that is bounded by the tendon of Todaro, the septal cusp of the tricuspid valve and the coronary sinus opening. This triangle of Koch contains the node of the triangle of Koch, which is really important for helping blood get to the ventricles. The blood that is collected in the atrium flows through the tricuspid valve and then it goes into the right ventricle. This is where the blood starts to get ready for circulation. The triangle of Koch and the atrioventricular node of the triangle of Koch play a role in this process.
INTERNAL STRUCTURE OF LEFT ATRIUM:
The left atrium gets blood that has oxygen in it from the four veins. It then sends this blood to the ventricle. The blood goes through the valve to get to the left ventricle. This is how the left atrium helps get blood to the rest of the body and the back wall of the atrium. The left atrium is smooth. It gets the pulmonary veins. The front wall and the left atrial appendage are not smooth. The left atrial appendage is like a pouch that looks like an ear. It helps when the left atrium has much pressure. The left atrial appendage helps control the amount of blood in the body. It does this by sending out helpers called atrial natriuretic peptide and brain natriuretic peptide. The left atrial appendage is important for the atrium. The left. The left atrial appendage works together to help the heart. The Left Atrial Appendage or LAA looks different in pictures. It can look like a chicken wing or a cactus or a windsock or a cauliflower. The cauliflower type of Left Atrial Appendage is more likely to have blood clots form in it. This is especially true for people, with a heart condition called fibrillation. Doctors can operate on the Left Atrial Appendage to close it or block it. This helps prevent strokes in people with fibrillation.
INTERNAL STRUCTURE OF THE VENTRICLES:
The heart has four parts called chambers. The ventricles are the chambers that pump blood out of the heart. They have thick walls because they need to be strong to pump blood. The atria are the chambers that get blood and then send it to the ventricles. The ventricles have to pump blood hard. They pump blood to the lungs or to the rest of the body. The left ventricle is the strongest because it pumps blood to the body. It has to be strong to pump blood all the way around the body. The right ventricle is not as strong because it only pumps blood to the lungs. The lungs are close to the heart so it does not need to be as strong as the ventricle. The inside of both ventricles has some muscles on the walls. These muscles are called trabeculae carneae. They are not found in the outflow tracts. There are three kinds of trabeculae carneae. One kind is like a ridge that is attached along its length. Another kind is, like a bridge that is attached at both ends. Then there are the muscles that stick out into the ventricles. The papillary muscles have strings that come out of them. These strings are called chordae tendineae. They are attached to the flaps of the valves. The right ventricle has a tricuspid valve. The left ventricle has a mitral valve. The chordae tendineae help to keep the valves from getting out of place when the ventricles contract. The right ventricle is the same size as the left ventricle. It can hold around 85 milliliters of blood in adults. The right ventricle makes up a lot of the surface of the heart and some of the bottom surface. The back wall of the ventricle is made by the wall between the ventricles. This wall bulges into the ventricle so it looks like a crescent shape when you cut through it. The right ventricle has two parts: one part where blood comes in which's rough and another part where blood goes out which is smooth. This smooth part is called the conus arteriosus. The conus arteriosus leads to the trunk. The right ventricle has a feature called the moderator band. The moderator band is also known as the trabecula. This moderator band connects the wall between the two chambers of the heart to the front muscle that controls the heart valve. The moderator band also carries part of the bundle branch of the system that helps the heart beat. The right ventricle and the moderator band work together to make sure the heart functions properly. The moderator band is a part of the right ventricle. The left ventricle is really long and muscular. It is also conical in shape than the right ventricle. This part of the heart is very strong. The left ventricle is what forms the point of the heart. It also makes up a part of the surface that faces the diaphragm. If you look at the ventricle from the side the inside space is almost a circle. The left ventricle has an area that the blood comes out of this is called the aortic vestibule. The aortic vestibule opens up into the ascending aorta. The left ventricle usually has two muscles. It does not have a moderator band like some parts of the heart do. The left ventricle is made up of a lot of mass this is about 143 grams on average. This shows that the left ventricle has to work a lot, than other parts of the heart. The left ventricular wall gets a lot thicker as we grow up it becomes three to six times thicker than the ventricle. This is because the left ventricle has to work hard to pump blood. It has to pump blood from a resting pressure of about 80 mmHg to 120 mmHg in the aorta, with each heartbeat. The right ventricle does not have to work hard because it is pumping blood into the lungs where the pressure is a lot lower. The left ventricle and the right ventricle are able to work to get blood flowing properly through the lungs and the rest of the body the left ventricle and the right ventricle make this happen. The heartbeat spreads toward the layer of the heart, which is called the ventricular epicardium. This causes the heart to contract in a synchronized way. The heartbeat happens in a way, which makes the heart pump blood efficiently. This is what creates the beating of the heart that you can see on a test called an electrocardiogram or ECG. At the level something important happens with the heart. Depolarization spreads between cardiac muscle cells. This happens because of gap junctions. The cardiac muscle cells are connected by these gap junctions. So when one cardiac muscle cell gets a signal the depolarization spreads to cardiac muscle cells through these connections. This is how cardiac muscle cells work together. The depolarization spreads from one cardiac muscle cell to another cardiac muscle cell through the gap junctions. The heart is made up of connections called intercalated discs. These intercalated discs are located within the heart muscle, which is also known as the myocardium. The myocardium is able to work as a team because of these intercalated discs. This means that the heart can contract and relax in a coordinated way. The heart beats as one unit, which is very important for its function. Additionally the presence of discs in the myocardium allows the heart to contract rapidly and uniformly. This is very helpful for the heart to do its job, which's to pump blood throughout the body. The myocardium and the intercalated discs work together to make sure that the heart beats in a steady way. The cardiac muscle has a time when it cannot contract again after it has already contracted. This prevents the muscle from having tetanic contractions, which means it can keep beating in a regular rhythm. The cardiac muscle cells are connected by electricity, which's necessary for the heart to work normally. However this connection can also allow bad electrical signals to spread. When the heart is damaged, like during an infarction the connections between the cardiac muscle cells can close. This helps to stop the signals from spreading to the rest of the heart. The cardiac muscle prevents contractions ensuring the heart keeps beating in a rhythmic activity. The electrical connectivity of the muscle is very important for the heart to function properly but it can also permit the spread of abnormal impulses like, during a myocardial infarction and the cardiac muscle can prevent this by closing the gap junctions.
BLOOD SUPPLY OF THE HEART:
The coronary arteries give the heart muscle, which is also called the other parts of the heart the oxygen they need from the blood. These coronary arteries start at the beginning of the ascending aorta, above the valve that controls blood flow from the heart into the aorta. The beginning of the aorta is called the root and it has three small areas that are bigger, than the rest these areas are called the aortic sinuses or the sinuses of the coronary arteries aortic root, where the coronary arteries arise from the aortic sinuses. The Valsalva is something to consider. The left coronary artery starts from the aortic sinus. On the hand the right coronary artery begins from the anterior, which is the right aortic sinus. There is also the sinus, known as the non-coronary sinus. Usually the non-coronary sinus does not have any vessels coming out of it. The major coronary arteries, like the Valsalva and their main branches are found on the surface of the heart. They are located in the interventricular sulci. Because of this the major coronary arteries are called coronary arteries. The coronary arteries, including the coronary artery and the right coronary artery are very important. The left coronary artery supplies the left atrium,left and most of the interventricular The septum is a wall that separates the heart into two parts. It divides mainly into two arteries: the left anterior descending artery and the circumflex artery. The left anterior descending artery goes down in the interventricular sulcus towards the apex of the heart. It gives blood to the walls of the ventricles and the interventricular septum. The left anterior descending artery also gives rise to diagonal branches. These branches form connections with posterior interventricular branches. The septum is very important for the heart to work properly. The left anterior descending artery and the circumflex artery are like two roads that give blood to the heart. The septal and diagonal branches are, like roads that connect these two big roads. The interventricular septum is the wall that separates the two ventricles. The left anterior descending artery gives blood to this wall. It is an important job that the left anterior descending artery does. The heart needs blood to work properly. The left anterior descending artery helps to give it that blood. Circumflex artery courses within the coronary sulcus to the left, supplying the left atrium and lateral wall of the left ventricle, and anastomoses with branches of the right coronary artery. The right coronary artery goes along the sulcus. It gives blood to the atrium and the right ventricle. The right coronary artery also gives blood to parts of the ventricle and a lot of the cardiac conduction system. The right coronary artery usually has branches that come off of it. These are called marginal branches. They give blood to the layer of the right ventricle. At the back of the heart the right coronary artery usually keeps going as the inter ventricular artery. Some people call this the posterior descending artery. This artery gives blood to the part of the wall, between the ventricles and the surrounding ventricular walls. The heart gets rid of blood through the veins. These veins take blood that does not have oxygen from the myocardium to the right atrium. Most of this blood goes into the sinus via the cardiac veins. The cardiac veins are really important for the heart because they help get rid of the blood that the myocardium does not need anymore. The right atrium then helps get this blood to where it needs to go. The cardiac veins and the coronary sinus work together to make sure the heart gets rid of the blood it does not need. The coronary sinus is like a vein that collects blood from the cardiac veins. The great,middle,and small cardiac veins,along with the posterior vein of the left ventricle and the oblique vein of the atrium is a special vein. The anterior cardiac. The smallest cardiac veins, also known as Thebesian veins, drain directly into the right atrium or cardiac chambers. Even though there are some connections between the branches of the arteries they are basically the only arteries that bring blood to the heart. So when one of the arteries gets blocked all of a sudden it usually causes myocardial infection in the coronary arteries or more specifically the coronary arteries and the heart muscle they supply the coronary arteries. The coronary arteries play a role in this.
CONCLUSION:
The human heart is a special muscle that is important for keeping blood moving all the time. It has a lot of parts like the pericardium and the chambers and valves that work together to keep blood circulating. The human heart is made up of the pericardium, pericardial sinuses, chambers, valves and coronary vasculature. All these parts of the heart help get blood to the lungs and the rest of the body. If we want to figure out what is going on with the heart when it is not working right we need to know what the human heart normally looks like and how it normally works. This is very important for dealing with problems like blood pressure, coronary artery disease and heart failure. The human heart is also affected by things, like angina and myocardial infarction. Cardiac surgery has gotten a lot better over time. So has transplantation and the way we use medicine to treat heart problems. This has really helped patients.. Even with these improvements heart disease is still one of the main reasons people die all around the world. To be a doctor or to do research you need to really understand how the heart works, what it looks like and how it affects people's health. You have to know about anatomy, which is the study of the heart's structure and cardiac physiology, which is the study of how the heart functions. Anatomy and cardiac physiology are very important. Understanding anatomy and cardiac physiology is crucial, for medical practice and research related to cardiac surgery and transplantation.
REFERENCES:
1) BD Chaurasia's Human Anatomy volume 1 Upper Limb and Thorax tenth Edition.
2) Text book of human anatomy Vishram singh vol-1 Upper Limb and Thorax 5th edition
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