User:Z5178463
| 2017 Project Groups | |||||
|---|---|---|---|---|---|
| Group 1 | Group 2 | Group 3 | Group 4 | Group 5 | Group 6 |
| Mark Hill - Lab 1 page | |||||
Primary Heart Field and Heart Tube Formation
At around day 15 of human development, the first cells start to migrate through the primitive streak to the anterior and lateral sections of the cranial end of the embryonic disc, forming bilateral primary heart fields. These primary heart fields resemble a crescent shape, as seen from Figure ().
At around day 18, the lateral plate mesoderm is split into two layers, namely the splanchnic mesoderm, facing the endoderm and the somatic mesoderm, facing the ectoderm. The former portion of the mesoderm gives rise to the heart. The portion between the splanchnic and somatic mesoderm is the presumptive pericardial space. Cells from the splanchnic mesoderm will merge to form 2 lateral endocardial tubes (also known as angioblastic cords) and as they form a lumen, are enveloped by myocardium. These endocardial tubes are as of now located inferior to the presumptive pericardial space.
At around 19-21 days, the embryonic disc starts to fold. This folding begins cranially and extends in a caudal direction. The endocardial tubes fuse and is now located between the pericardial space and newly formed foregut that becomes surrounded by pericardial space (also known as the pericardial coelom). At this stage, the myocardium does not completely engulf the endocardial tubes. Instead, it remains in a continuous attachment with the non-cardiac splanchnic mesoderm through a structure called the dorsal mesocardium.
At this point, the primitive heart tube is bilaterally symmetrical and resembles an inverted Y shape. Starting from the inflow tract, there is the right and left sinus venouses that receives blood from the embryo, followed by the primitive atrium, primitive ventricle, bulbus cordis and then the truncus asteriosus which gives rise to the aortic and pulmonary trunk. [1]
<pubmed> PMC1767747</pubmed> Z5178463
Here is the Student Page demonstration page I showed in the Practical class.
Use this page to practice editing and don't forget to add a topic to the 2017 Group Project 3 page.
- ↑ <pubmed> PMC1767747 </pubmed>
