Embryo Research Paper

The hearts function as a double pump that serves two circulations. The pulmonary pump in the right side of heart is provided for the gas exchange in the body, and the systemic circulation in the left side provides the functional blood supply to all body tissues. The functional blood to the heart is provided by the coronary arteries. Right coronary artery supplies the heart through the posterior interventricular and marginal artery branches; and the left coronary artery supplies the heart via anterior interventricular artery and the circumflex artery. The myocardium is drained by great, small, and middle cardiac veins which

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.

In the neural tube, neuroepithelial cells line the ventricular wall, are densely packed, and form the ventricular zone. They will eventually divide and form radial cells which act as stem cells and provide scaffolding. While continuing to migrate, migrating cells then differentiate into neurons and glia. The development of the brain can now be considered, from a cellular viewpoint, as a sequence of six different stages, most of which happen during prenatal life. We first start off with phase 1, neurogenesis, which is the mitotic division of nonneuronal cells to produce neurons, phase 2, cell migration, is the massive movements of nerve cells or their precursors to distinct areas of the nervous system. The 3rd phase is cell differentiation, the changing of cells into distinct types of neurons or glial cells. Then we have the 4th stage of synaptogenesis, the formation of synaptic connections, which are equal to small gaps through which nervous system cells communicate to one

In a normal human being the heart correctly functions by the blood first entering through the right atrium from the superior and inferior vena cava. This blood flow continues through the right atrioventricular valve into the right ventricle. The right ventricle contracts forcing the pulmonary valve to open leading blood flow through the pulmonary valve and into the pulmonary trunk. Blood is then distributed from the right and left pulmonary arteries to the lungs, where carbon dioxide is unloaded and oxygen is loaded into the blood. The blood is returned from the lungs to the left

The blood that does not cross the foramen ovale into the left atrium is emptied into the right ventricle which is then pumped into the pulmonary artery to be carried to the lungs. The third fetal shunt is encountered; the ductus arteriosus allows blood to be shunted from the pulmonary artery to the aorta and systemic arteries following. Blood that does go to the lungs are returned by the pulmonary veins to the left atrium and emptied into the left ventricle. (Perinatal and Pediatric Respiratory Care, Ch2 p 17-18) Shortly after birth due to changes in vascular resistance blood is redirected to the lungs for oxygenation and these shunts are no longer required leading to their closure within a few days postpartum. In HLHS, because the left heart structures are insufficient to receive and pump adequate amounts of oxygenated blood to supply the tissues the patency of the foramen ovale and the ductus arteriosus are essential to sustaining life. (PubMed – ADAM Medical Encyclopedia, 2013) Medical intervention is needed to maintain the patency of the ductus arteriosus and an atrial septal defect is created in place of the foramen ovale.

Lastly, the embryo enters the next stage known as the fetus, taking place on the ninth week and lasting all the way through childbirth. At this time, “The neural tube develops into the brain and spinal cord and neurons form” (Cherry, 2015). Majority of the physical growth takes place in this stage. It is the longest and most amazing stages of life! The Miracle of Life emphasizes, “without ever mixing the blood of the baby’s and mom’s; grabs oxygen,” the enriched blood flows through the umbilical cord and into the fetus without ever mixing with the mother’s blood (Cort, 2001).

During pulmonary circulation the blood moves from the heart to the lung to become oxygenated, the blood is then circulated back to heart. Deoxygenated blood enters the right atrium from the superior and inferior venae cavae. The blood is pumped through the tricuspid valve into the right ventricle. The blood is then pumped through the pulmonary valve and into the pulmonary artery from the right ventricle.

Total anomalous pulmonary venous connection is a one of rare congenital heart defect. Its accounts 1% of total prevalence of heart defect abnormality. The estimated number of the cases is about one out of 10,000 live (1).The consequence of disrupting the normal development of venous drainage during gestational period leads to this malformation. That will lead to drainage of the pulmonary veins into the right atrium or branches of veins returning to the heart instead of drainage into the left atrium. A surgical repair of this anomalous considers the optimal treatment because it has shown a great decrease in death rate throughout the first year of life (2). Surgical intervention aims to establish a communication between the left atrium and the

Congenital heart defects are problems intrinsic to the heart that present at birth. They develop during fetal growth in utero mainly due to genetic malformations, environmental factors, and multifactorial reasons. The environment within which the fetus develops (the uterus) is a very crucial contribution to normal fetal growth and development. It is common to find disruptions within this microenvironment; the consequent effect being the disruption of normal growth and organ developments. The timing is, however, important as well. During the first trimester, organs are being crafted from primitive cells and tissues. Internal and external factors, therefore, take the opportunity to cause disruption. The most common congenital anomalies are

The direction blood flows from the heart to lungs and back to the heart: Deoxygenated blood enters the heart through the right atrium. The contraction of the right atrium forces blood through the atrial ventricular valves known as the tricuspid and bicuspid valves. Once the atria fills up, the valves open, and blood is able to pass through the right ventricle. The right ventricle contracts to force blood into the pulmonary semi lunar valve into the pulmonary lunar artery. The blood travels through the pulmonary arteries to the lungs to get oxygenated. Once it gets oxygenated, it then returns back to heart through pulmonary veins, then the left atrium, then through the bicuspid valve to the left ventricle, then through the aortic semi lunar valve, then to all the tissues of the

The mother’s body sustains the heart of its unborn child; that in itself is poetic. The cardiovascular system is the first (dual) system to form during pregnancy. The heart and a nascent circulatory system will form during the first few weeks of gestation. Between the 4th and 5th week of gestation the heart is now beating at a sturdy pace and blood flow has begun in the main vessels. By week ten of a pregnancy, the heart has fully formed, with two atria, two ventricles, and two blood vessels to carry blood from the heart, the aorta, and pulmonary artery. Circulation differs between babies and fetuses, because a fetus is incapable of using its lungs to breathe. A majority of fetal blood does not pass through the lungs but rather pushed through

Isolated case reports, however, provide the only information about the evolution in the uterus of this spectrum of diseases in the second and third trimesters, and they suggest potential progression in the degree of left heart hypoplasia. Therefore, in the present study, the researchers retrospectively reviewed the prenatal and postnatal echocardiograms of 21 fetuses with left heart obstructive lesions. Table 1 shows the research that was found on the 21 fetuses (Hornberger et al; 1995). The researcher also attempted to identify prenatal features that could indicate the severity of postnatal left heart obstruction and hypoplasia. Fetuses were divided into groups according to whether postnatally the left heart was capable or incapable of supporting the systemic circulation in the presence of a patent aortic valve. Group 3 included fetuses with aortic atresia. At the initial examination, left heart dimensions were normal or reduced, with the most unusually small measurements in group 3. Three fetuses in group 2 and most in group 1 had normal initial left heart dimensions. Subsequent growth of left heart structures either paralleled normal growth or was reduced, the latter resulting in the development or progression of left heart hypoplasia. All left heart dimensions grew more slowly in group 2 and group 3 than in group 1. Other prenatal features observed only in groups 2 and 3 included reversed or bidirectional foramen ovale flow and retrograde distal arch flow. Initial mid-trimester mitral valve and the growth rates of all left heart structures correlated strongly with postnatal left ventricular end-diastolic dimension, there could be additional indicators of postnatal disease severity. In group 1, one fetus developed severe aortic stenosis late in

The Heart is hollow organ which is composed of four muscular chambers the right and left atrium and ventricles that is specialized for pumping blood throughout the body. The heart is also consists of four valve; two atrioventricular valve which is the bicuspid and tricuspid valve that is allowing blood to flow in the atria and closes when there is a increase ventricular pressure that prevent backflow into the atria as ventricles contract (Craft, Gordon, and Tiziani, 2011), and the semilunar valves which include the pulmonary and aortic valves is located at the exit of the large arteries from the ventricles that opens when there is intraventricular pressure exceeded the aortic and pulmonary pressure which allows the blood flow into the systemic

In the placenta, the chorionic villi are thought to control the fetal blood flow to the materno/fetal exchange area located in the peripheral villi 4 .

After thickening of chamber walls during cardiac embryogenesis, oxygen and nutrients can no longer be passively diffused into cardiac cells, therefore, a primitive vascular develops to supply these vital resources. The plexus then further matures into coronary arteries and veins which ensures continued development of the heart. However, the vasculogenesis of these coronary blood vessels is not fully understood and has been a topic of intense research and debate. Over time, various models have been proposed, indicating the importance of cellular and molecular signals regulating vascularization of the embryonic heart. Interestingly, research has highlighted the contribution of extra cardiac cells which migrates and differentiates in the heart.