Deep anatomy: help you understand her and his heart

More than 500 years ago, Leonardo da Vinci painted the inside of the heart, but since then people have never understood the subtle structure of the heart. Now, new research has finally given some answers. Seemingly useless structures are also crucial to the heart. Scientists took centuries to understand the heart, are you sure you understand it now? < / P > < p > in the long embryonic development process of human embryos, the heart is the first organ to begin to develop. About 4 weeks after fertilization, the heart can start to beat autonomously, and the first beat of the heart also means that life begins to send a signal of “I am coming” to the world. In addition to the pioneer of physical development, the heart is also regarded as a symbol of sincerity in many cultures. Whether it means “no heart” in language or an oath with the hand on the left chest in action, the heart represents the whole loyalty of an individual. In the history, human beings have never stopped trying to understand the secret of this important organ. In the second century A.D., Galen, an ancient Greek medical scientist, described the heart as “a piece of flesh that is not easy to be injured and hard, and has fiber content that other organs do not have.” in the absence of anatomical support, Galen believed that human nerves originated from the heart. But in the 11th century, the medical scientist Avicenna, after combining some ideas of Aristotle, believed that the heart can produce respiration and heat the whole body. With the revival of anatomy in the middle ages, these ideas were subverted. After analyzing the structure of the heart, we can basically distinguish the left and right atrium and ventricular structure of the heart. At the end of the 15th century, Leonardo da Vinci described the structure of the human heart. According to the records, human beings can finally see the general structure of the heart. In some fine paintings, Leonardo also shows the internal structure of the heart, and describes the complex muscle fiber myocardial trabecula. < p > < p > at that time, medical experts believed that myocardial trabeculae was just an accessory of the heart, which was the place to heat the blood flowing through it. However, the medical experts in the middle ages still didn’t understand our hearts, and these conjectures are not accurate now. With the help of modern biological technology, some studies have found that these myocardial trabeculae on the surface of the heart chamber appear in the early stage of heart development. Scientists have speculated that the oxygen demand of the heart is very large in the early stage of heart development, and the myocardial trabeculae can be responsible for oxygen supply to the developing heart. When the heart is fully developed, the trabeculae becomes a residue. It is not clear what role it has in the adult heart. < / P > < p > according to some cell lineage tracking results, it can be confirmed that the molecular and developmental characteristics of myocardial trabeculae are different from those of large myocardium, and the surface of many myocardial trabeculae may help transport oxygen and nutrients from the blood. However, most of these are conjectures from the emergence of Leonardo da Vinci’s paintings. < / P > < p > now, we finally have a chance to see through the most mysterious structure of our heart. With the help of the British biological sample bank containing 500000 human samples, scientists have been able to understand more specifically the structure of the heart and the genetic differences in different regions. The database contains a large number of heart samples, and researchers at the European Laboratory of molecular biology used 25000 cardiac magnetic resonance images, which were analyzed with artificial intelligence. < / P > < p > according to the published articles, the researchers found that in the adult heart, the myocardial trabecula also plays a role, which makes the inner surface of the heart chamber no longer smooth, which can ensure that the resistance of the blood output during each heart beat is reduced, and it can pass through the ventricle more effectively. This is similar to the holes in a golf ball that seem to block the ball’s movement, but they actually reduce air resistance and allow the ball to fly further. < / P > < p > since it is difficult to get a glimpse of the myocardial trabeculae, the researchers decided to identify the genes that control its growth at one time. A genome-wide correlation analysis was conducted based on the fractal dimension of myocardial trabeculae in different samples, and finally 16 gene loci were found to be significantly related to the development of myocardial trabeculae. Among them, the mutation site in Mtss1 gene is the most concerned, because this site has correlation with cardiac structure and functional phenotype. < / P > < p > in mouse embryos, the researchers used CRISPR / cas9 to knock out the Mtss1 gene, resulting in a large number of death in mouse embryos. However, the heart development of mice that could grow would be damaged. Compared with the control group, the heart volume of these deficient mice was smaller and the structural development was slower. Under the microscope, it can be clearly seen that the formation of myocardial trabeculae in mice with Mtss1 expression impairment is blocked. In addition, it is also related to the Sr2 gene fragment in the development of heart. When it comes to dendrites, can you also think of the curved appearance of myocardial trabeculae? These two genes may play a key role in the formation of such curved structures. The findings of this study may also find a link between the brain and the heart. This is because Mtss1 is also highly expressed in the cerebellar Purkinje cells and allows actin to develop and grow in branches rather than straight lines. This branching pattern also increases the surface area of the tissue, which is inseparable from the information processing function required by the nerve or the hemodynamic function required by the heart. Therefore, these two genes highly related to the development of myocardial trabeculae may also determine the neural development function of the brain. < / P > < p > these structural and genetic data have finally enabled scientists to understand myocardial trabeculae. Myocardial trabeculae plays an important role in the adult heart. Its complexity determines the blood output, pulsatile function and cardiac output index during heart beating. The more and more complex the myocardial trabeculae, the stronger the above functions. Like the golf ball mentioned above, when blood flows through the ventricles, the myocardial trabeculae can reduce resistance and accelerate blood transport. In disease analysis, the number of myocardial trabeculae is directly related to dilated cardiomyopathy, heart failure and other diseases. If the number of myocardial trabeculae increases, the risk of these heart diseases will be lower. The discovery of this study means that myocardial trabeculae can finally be named. It also plays a role in the heart of adults. Whether in terms of structure, gene or disease, it affects the operation of the heart. 500 years after Leonardo da Vinci painted the trabeculae of the heart, scientists finally understood the unknown region of the heart. Today, the myocardial trabeculae is also in your heart and your partner’s heart, helping it pump blood more efficiently. And when your heart rate and blood flow increase tonight, you will enjoy the benefits of myocardial trabeculae. Now, it’s also time to lead the other party to understand the incompletely understood heart. Focus