The human heart is a myogenic muscle vital to human life as it is the muscle which deals with the pumping of oxygenated and deoxygenated blood throughout the entire body. Due to importance of the heart an understanding of this complex muscle is necessary. Therefore, today I hope to discuss the embryology of the heart.
The formation of the heart begins during the third week of development, the embryo undergoes gastrulation in the embryonic plate producing three germ layers (ectoderm, mesoderm and endoderm). Originally the embryonic plate possesses two germ layers (ectoderm & mesoderm) until pregenital heart cells from the ectoderm migrate through the primitive streak in to splanchnic mesoderm forming the third germ layer (endoderm) creating the primary heart field a region responsible for the formation of the left ventricle, atria and a part of the right ventricle.
Consequently, the heart is derived from the splanchnic mesoderm layer where it spreads laterally and cranially. Cells predestined to create the heart form a crescent at the cranial border of the disc, transforming the ectoderm into a neural plate and eventually into a neural tube due to continuous folding. The development of the heart is relative to the development of the brain because as the cranial end of the neural tubes grow they derive folding of the disc resulting in a tube.
Due to continuous folding the position of the cardiac plate inverts eventually folding in to a tube surrounded by the recently formed
The atrium chambers are small and collect blood returning to the heart from the systemic or pulmonary circulation. The ventricles are larger than the atrium chambers and they pump blood out into the circulation. The right atrium and right ventricle are separated by the tricuspid valve. The tricuspid valve has three flaps that prevent backflow of the blood from the right ventricle into the right atrium. The left side of the heart has a mitral valve also known as the bicuspid valve that consists of two flaps that separates the left atrium and left ventricle. The heart has a thick wall that is mainly of muscle and is constantly contracting and relaxing through every heartbeat. The hearts wall has three layers of tissue which consist of the innermost layer called the endocardium which is a smooth, thin membrane that lines the inside of the champers of the heart and forms the surface of the valves. The second layer is the middle layer that is called the myocardium. It is the muscular wall of the heart and is made of many layers of cardiac muscle which is striated and involuntary muscle tissue. Then the outer layer of the heart is the epicardium that is a double layered fibrous sac that covers and protects the heart.
In this experiment, the external and internal structures of a sheep’s heart was examined and identified by dissection. To determine the functionality of a human heart since they are both mammals.
The heart is divided into four chambers, upper left, upper right atrias, lower left and lower right ventricles. The right atrium and ventricle are called the right hearts and the left as the left hearts. The heart is enclosed in a protective sac, the pericardium, which contains a small amount of fluid. There are
How does the structure of cardiac myocytes and intercalated disks follow the function of cardiac muscle tissue
R E V I E W S H E E T 30 Anatomy of the Heart
Oxygen and nutrients the body requires for function are pumped around this complex network of blood vessels by the heart. At roughly the size of a human fist, the heart is a four-chambered muscle and performs two functions of circulation simultaneously and continuously. Systemic and pulmonary circulation. The heart is made up from three separate layers of cardiac tissue; the outer layer called the pericardium, which is a double sac-like outer covering with serous fluid inside to keep the middle layer, the myocardium from adhering to the outer layer. This middle layer of the heart is the heart muscle which is thicker on the left side, to aid with the pressure needed to sustain systemic circulation. The inner layer of the heart is the endocardium. It’s lining is smooth to help prevent the blood which circulates around the inside of the heart from clotting. The heart is the human body’s in-built pacemaker, and the electrical signals sent through the it cause the heart to contract and relax. This process is triggered by the autonomic nervous system and the contraction and relaxing cycle is
The heart consists into three layers in which are endocardium, the myocardium, and the epicardium. The endocardium is the inner layer of the heart (chambers and valves). The myocardium is the middle muscular layer which is responsible for heart contraction. The epicardium is the outside layer of the heart
In this lab, we dissected a sheep heart. We observed the external characters of the heart including the arteries, veins, and apex of the heart. We identified the apex of the heart and we concluded that it was at the bottom point of the heart. We then started dissection of the
Located between the parietal and visceral layer is the pericardial fluid, this is emissions of pericardial cells that helps reduce friction between layers as the heart moves and thumps. The heart has three layers; the epicardium (made up of two tissue layers the visceral layer and serous pericardium layer). This layer of the heart is made out of mesothelium which is a thin transparent layer that is a delicate fibroblastic tissue and adipose tissue. This adipose tissue starts to get thickest over ventricular surfaces where the hearts coronary and cardiac vessels are found. The center layer of the heart is the myocardium (this layer is in charge of the pumping activity of the heart and is made out of cardiovascular muscle). The myocardium consists of ninety-five percent of the hearts wall, which consists of muscle fibers. The cells in the myocardium layer are muscle strands. The cardiovascular muscle fibers structure bundles and whirl slantingly around the heart which is in charge of the heart 's pumping activity. The internal layer of the heart is the endocardium (this is a flimsy layer of endothelium tissue overlying a thin layer of connective tissue). This layer gives a smooth coating layer to the chamber of the heart and spreads the valves of the heart. This smooth layer lessens friction as blood moves all through the heart. The endothelium and endocardium have large veins that connect to the heart. The heart is four chambers; two
First, there is a lot of information about the heart. The organ works ceaselessly, beating 100,000 times a day, 40 million times a year—in total clocking up three billion heartbeats over an average lifetime. It keeps the body freshly supplied with oxygen and nutrients, while clearing away harmful waste matter. The fetal heart evolves through several different stages inside the womb, first
The normal flow of blood through the heart consists of the entry of blood to the right atrium through to the right ventricle and then the blood passes through the tricuspid valve entering the lungs and then through to the left atrium and to the left ventricle via the mitral valve and finally into the body. During fetal development, however there are the risks for congenital anomalies. These congenital heart disorders consist of Atrial septal defect (ASD) and Ventricular septal defect (VSD). ASD is one of the common congenital heart defects that requires interventional measures or repair. The condition occurs when the foramen ovale the opening between the atria prior to birth does not close and there
The heart is a muscular four-chambered organ whose primary purpose is to pump blood throughout the body. The heart is the first functioning organ in the embryo. Its first pulsatile movements begin during the third week after conception. This early development of the heart is essential to rapidly growing embryo as a means of circulating nutrients and removing waste product. Most of the
2. Zak, Radovan, ed. Growth of the Heart in Health and Disease. Raven Pr, 1984.
According to parents.com, after conception, a fetus begins to develop rather quickly. In the fifth week of pregnancy, a baby’s heart begins to beat. A baby also develops three distinct layers, ectoderm, endoderm, and mesoderm. These three layers will eventually form the body systems that are necessary
Surrounding each of these valves are dense fibrous rings or annuli made of connective tissue that forms the cardiac skeleton. The annuli of the aortic valve forms the base for the other annuli as it is located central to the other valves. Fibrous extensions from the annuli of the aortic valve extends outwardly and anchors the other three valves. In addition to the four annuli there are other fibrous components of the cardiac skeleton such as the right and left fibrous trigones, and the membranous septum. The right fibrous trigone is also know as the central