Ostium primum

From Wikipedia, the free encyclopedia

Ostium primum
Interior of dorsal half of heart from a human embryo of about thirty days. (Ostium primum visible below septum primum, but not labeled.)
Gray's	subject #135 512
Dorlands/Elsevier	o_09/12602009

In the developing heart, for a time the atria communicate with each other by an opening, the ostium primum of Born (interatrial foramen primum), below the free margin of the septum.

This opening is closed by the union of the septum primum with the septum intermedium, and the communication between the atria is reëstablished through an opening which is developed in the upper part of the septum primum; this opening is known as the foramen ovale (ostium secundum of Born) and persists until birth.

[edit] External links

• Overview and diagram at um.edu.mt
• Diagram of Ostium Secundum Atrial Septal Defect at Mayo Clinic
• MedEd at Loyola GrossAnatomy/thorax0/Heart_Development/Atria.html
• GPnotebook -402259967 - ostium primum atrial septal defect

This article was originally based on an entry from a public domain edition of Gray's Anatomy. As such, some of the information contained herein may be outdated. Please edit the article if this is the case, and feel free to remove this notice when it is no longer relevant.