- Source: Septum secundum
The septum secundum is a muscular flap that is important in heart development. It is semilunar in shape, and grows downward from the upper wall of the atrium immediately to the right of the septum primum and ostium secundum. It is important in the closure of the foramen ovale after birth.
Structure
= Development
=At the end of the fifth week of development, the septum secundum grows from the upper wall of the primitive atrium. It grows to the right of the septum primum, which has already started growing. It grows down towards the septum intermedium formed from the endocardial cushions. Before birth, it does not fuse with the septum intermedium, leaving a gap to form the foramen ovale. Shortly after birth, it fuses with the septum primum to form the interatrial septum, and the foramen ovale is closed. The fossa ovalis denotes the free margin of the septum secundum after birth.
Clinical significance
Sometimes, the fusion of the septum secundum to the septum intermedium is incomplete, and the upper part of the foramen remains patent. This creates an atrial septal defect (ASD).
References
This article incorporates text in the public domain from page 512 of the 20th edition of Gray's Anatomy (1918)
External links
Embryology at Temple Heart98/heart97a/sld037
cardev-039—Embryo Images at University of North Carolina
Overview at edu.mt
MedEd at Loyola GrossAnatomy/thorax0/Heart_Development/Atria.html
Kata Kunci Pencarian:
- Septum secundum
- Foramen ovale (heart)
- Interatrial septum
- Foramen secundum
- Atrial septal defect
- Congenital heart defect
- Primitive atrium
- Heart development
- Septum primum
- Human embryonic development
