The heart goes through many stages of change during embryonic development including those of cardiac looping and heart tube fusion (Martinsen 2005). The heart is of interest as many fatalities are due to heart defects and understanding the changes throughout the process of heart development could help with identifying the causes and treatments for these defects. In this report, the structure of the heart in the chick embryo at 40 and 56 hours will be compared.
There are several differences that were able to be observed when looking at the specimens in lab. First, the size of the heart has increased in the 56-hour chick compared with the 40-hour chick. The myocardium is divided into two regions, the compact myocardium which is important for
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In the 56-hour chick embryo, the position of the sinus venosus and primitive conus shifts as a result of cardiac looping. During chick development, the sinus venosus has a role as the pacemaker and the conus is a part of the outflow tract that eventually forms the arterial pole of the heart (Burggren and Keller 1997; Martinsen 2005). At 56 hours, the primitive conus moves ventral to the right atrium and the sinus venosus moves dorsal to the atria (Martinsen …show more content…
There are many genes and proteins that play a role in the formation of the heart in chick embryos. It is known that heart tissue is derived from cells that migrate out of the primitive streak and into the anterior lateral plate, whereas cells that migrate to the posterior plate form erythrocytes (Martinsen 2005; Martin et al. 2001). During migration to the anterior lateral plate, the cells are thought to receive signals from the anterior endoderm that direct them to form heart tissue (Marvin et al. 2001).
Marvin et al. (2001), demonstrated that the proteins Crescent and Dkk-1, both of which are Wnt antagonists and present in the anterior endoderm, are necessary for the formation of heart tissue. In the posterior lateral plate, Wnt-3a and Wnt-8c are expressed. When Crescent or Dkk-1 were injected into posterior lateral tissue, heart tissue began to be formed in this area where erythrocytes are normally made. Crescent and Dkk-1 are present in the anterior endoderm, inhibiting the expression of Wnt-3a and Wnt-8c. The inhibition of Wnt-3a and Wnt-8c by Crescent and Dkk-1 is thought to be what causes heart tissue to be formed in the anterior lateral plate, but not the posterior lateral
First and foremost, Eisenmenger syndrome was initially described in 1897 when German physician, Victor Eisenmenger, reported on a patient with symptoms of dyspnea and cyanosis from infancy that subsequently developed heart failure (Connolly, 2014). The postmortem description was revealed and a ventricular septal defect was discovered (El-Chami et al., 2014a). With that being said, this had been the first time that the link between a large congenital cardiac shunt defect and the development of pulmonary hypertension had ever been noted (El-Chami et al., 2014b). The normal heart has four chambers. The two upper chambers are separated from each other by the atrial septum (NORD, 2014a). The two lower chambers are known as ventricles and are separated from each other by the ventricular septum (NORD, 2014b).
Introduction: The purpose of this lab is to have a better understanding of the internal and external anatomy. The reasons for performing this lab is that pigs are similar to humans because they have skin, omnivores and as fetus they receive nutrients from an umbilical cord connected to the mother. As well as the similarities to human organ systems. The hypothesis of this lab is if the fetal pig has a similar organ system of a human and assuming those organs will be in the same locations as in a human then the organ systems should operate in the same fashion. Based on what I’ve learned from this lab and what I’ve learned during lecture I predict that the fetal pigs nervous and circulatory system would operate and look the same way as in a human.
of the heart: one chamber is on the top and one chamber is on the
...ape formation, movement of cardiac progenitor cells, heart tube, and heart function. A novel development of more specific assays, advance genetic screen efforts will provide new knowledge on cardiac development in the following years. Additionally, because of the zebrafish distinct features and its similarities to vertebrae, the zebrafish might become many researchers preferred model organism to study many mammal organs. Recently, the zebrafish has been used to study mechanisms that cause human cardiac and liver diseases and to model human hereditary and developed cardiac diseases. Due to the increase in sequencing efforts, the developing interest to study human liver and cardiac diseases. Also, the increase of resource and the more availability of the zebrafish model used in clinical and basic researchers involved in studying the liver, as well as cardiac diseases
The evolutionary development of the heart has come a long way from the singular tube to the multi-chambered complex ones that now operate in humans. Some scientists proclaim that the genetics over the years have not changed much at all. They also say that the human heart is a perfected machine that has seemed to reach the goal of its evolutionary time. However, the heart will continue to amaze us. With its constant abnormalities, gene mutations, and it’s striving for perfection, the heart will never be completely known and understood. Instead it will be an enigma, constantly dodging our rules and always providing us with life.
1.1 Describe, in-depth, stages of development from conception to birth in groups of 4 weeks i.e. 0-4, 4-8, 8-12...36-40 weeks.
A heart attack is a serious condition that results in long term damage to survivors’ hearts. For example, scar tissue from a heart attack can weaken or harden the heart muscle, causing it to be less elastic, and as those tissues spread into the aorta, the heart muscle can no longer complete a full contraction. These conditions could lead to heart failure immediately or over time. Heart transplants are one way to avoid these conditions, but donor hearts are in short supply. Recently, an alternative gene therapy has been tested and proven successful in pigs who have suffered heart attacks. Researchers came to this conclusion by assigning eighteen pigs who were recovering from heart attacks to receive injections of the Cyclin A2 gene that was exp...
We progressed the observation to the lungs and the heart. I had a moment of confusion when I saw the heart because the apex was protruding out from between the lungs. I had forgotten we were dissecting an animal and I did not adjust my thinking of anatomy from humans to animals. Since the entire heart of the sheep was not embedded between the lungs, it required extra support to protect it from trauma and force. This explained why the sheep heart was
What gonna form is primitive umbilical ring , and the communication between extra embryonic and intra embryonic cavity will be lost by the lateral folding .
The blood that moves through the embryo is in reality more entangled than after the child is conceived (ordinary heart). This is on the grounds that the mother (the placenta) is taking every necessary step that the child's lungs will do after birth.
... The scientists found that the hearts regrew without sccaring subsequent to injury. They found that the regeneration in the zebrafish heart is not driven by stem cells but rather by the proliferation of the existing cardiomyocytes (muscle cells of the heart). They also point out that the exhibition of this regenerative response could be due to heart enlargement via hypertrophy or hyperplasia.
The global picture that emerges is one that illustrates cellular contributions from multiple sources. It may be that endocardial budding generates most intramyocardial coronaries, while angiogenic sprouting from the sinus venosus generates most subepicardial coronaries and a subset of intramyocardial coronaries. PE cells may contribute to a fraction of both EC populations, and give rise to most of the supporting smooth muscle cells, as well as contributions from preotic neural crest cells.. Evaluating and quantifying the contribution of each proposed cell source by anatomical location will be the next important step in furthering our understanding of coronary growth
Since 1871, ascidians, or sea squirts, which are simple invertebrate chordates, have been used as model organisms to study embryonic development. The ascidia embryo represents an ideal model for vertebrate development because it has the same basic developmental and morphologic features of vertebrates. Furthermore, as a less complex organism, the ascidians have only a few hundred cells rather than the thousands of cells found in most vertebrates. The ascidia species was also chosen as a model organism because it has a...
A fish heart is one of the simplest vertebrate hearts. The circulatory system is a single circulation, with a two-chambered heart. The blood from the fish’s atrium is pumped into the ventricle. Blood is pumped to the gills from the ventricle where gas exchange occurs in the gill filaments. This is called gills circulation. The carbon dioxide is removed while the oxygen is taken in. This re-oxygenated blood is then transport to the rest of the body’s tissues and organs to get rid of carbon dioxide and exchanging it with life-giving oxygen. This circulation is called systemic circulation. Blood is eventually pumped back into the heart’s atrium chamber where the circulation begins again. This unidirectional flow of blood creates a gradient of
In the process of gastrulation, the heart tube forms. For humans, this stage begins in the third week of conception. “At this stage, the developing heart itself consists of a plate of pro myocardial cells. The cardiac plate is positioned inferior to the presumptive pericardial cavity, which has arisen as a space within the mesoderm.”(From Conception to Birth)With continuing folding of the disc, this heart forming region is moved into the developing neck of the