Target type: biologicalprocess
The process in which anatomical structure of an atrial septum secundum is generated and organized. [GOC:mtg_heart]
The atrial septum secundum (ASS) is the primary structure responsible for separating the right and left atria of the heart, ensuring that oxygenated blood from the lungs does not mix with deoxygenated blood returning from the body. Its morphogenesis, the process of its development, is a complex series of events starting early in embryonic life.
The development begins with the formation of the septum primum, a thin, crescent-shaped membrane that grows from the roof of the atrioventricular canal towards the endocardial cushions. As the septum primum grows, it leaves a small opening called the ostium primum.
Simultaneously, the septum secundum, a thicker, muscular structure, begins to develop behind the septum primum. Initially, it appears as a ridge that progressively grows and expands to cover the ostium secundum. The septum secundum develops from the right atrium wall and grows towards the septum primum.
As the septum secundum expands, it eventually covers the ostium primum, leading to the formation of the foramen ovale. This foramen serves as a crucial shunt for fetal circulation, allowing oxygenated blood from the placenta to bypass the pulmonary circulation and directly enter the left atrium.
During the later stages of fetal development, the septum primum fuses with the septum secundum, effectively sealing off the foramen ovale. This fusion process, called closure of the foramen ovale, is crucial for normal circulatory function after birth.
The morphogenesis of the atrial septum secundum is influenced by several factors, including:
* **Genetic factors:** Mutations in genes involved in heart development can disrupt ASS formation.
* **Hemodynamic forces:** Blood flow patterns within the heart play a role in shaping the septum secundum.
* **Growth factors:** Signaling molecules, such as bone morphogenetic proteins (BMPs) and fibroblast growth factors (FGFs), regulate cell proliferation and differentiation during septum secundum development.
The complex interplay of these factors ensures the proper development and function of the atrial septum secundum, ultimately ensuring the separation of oxygenated and deoxygenated blood within the heart.'
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| Protein | Definition | Taxonomy |
|---|---|---|
| Histone-lysine N-methyltransferase NSD2 | A histone-lysine N-methyltransferase NSD2 that is encoded in the genome of human. [PRO:DNx, UniProtKB:O96028] | Homo sapiens (human) |
| Compound | Definition | Classes | Roles |
|---|---|---|---|
| s-adenosylhomocysteine | S-adenosyl-L-homocysteine : An organic sulfide that is the S-adenosyl derivative of L-homocysteine. S-Adenosylhomocysteine: 5'-S-(3-Amino-3-carboxypropyl)-5'-thioadenosine. Formed from S-adenosylmethionine after transmethylation reactions. | adenosines; amino acid zwitterion; homocysteine derivative; homocysteines; organic sulfide | cofactor; EC 2.1.1.72 [site-specific DNA-methyltransferase (adenine-specific)] inhibitor; EC 2.1.1.79 (cyclopropane-fatty-acyl-phospholipid synthase) inhibitor; epitope; fundamental metabolite |
| scutellarein | scutellarein : Flavone substituted with hydroxy groups at C-4', -5, -6 and -7. scutellarein: aglycone of scutellarin from Scutellaria baicalensis; carthamidin is 2S isomer of scutellarein; do not confuse with isoscutellarein and/or isocarthamidin which are respective regioisomers, or with the scutelarin protein | tetrahydroxyflavone | metabolite |