Search results
Results From The WOW.Com Content Network
Atrial septal defect (ASD) is a congenital heart defect in which blood flows between the atria (upper chambers) of the heart.Some flow is a normal condition both pre-birth and immediately post-birth via the foramen ovale; however, when this does not naturally close after birth it is referred to as a patent (open) foramen ovale (PFO).
The foramen ovale (from Latin 'oval hole') forms in the late fourth week of gestation, as a small passageway between the septum secundum and the ostium secundum. Initially the atria are separated from one another by the septum primum except for a small opening below the septum, the ostium primum .
A flap of tissue called the septum primum acts as a valve over the foramen ovale during that time. After birth, the introduction of air into the lungs causes the pressure in the pulmonary circulatory system to drop. This change in pressure pushes the septum primum against the atrial septum, closing the foramen. [1]
[2] [3] Although there are many routes an embolism may take to enter the arterial circulation, the term paradoxical embolism most commonly refers to a clot passing through a patent foramen ovale. The formen ovale is open during development of the heart in a developing fetus, and normally closes soon after birth - studies have found that patent ...
Some of the blood entering the right atrium does not pass directly to the left atrium through the foramen ovale, but enters the right ventricle. This blood consists of oxygenated placental blood and deoxygenated blood returning from the fetal circulation. [2] This blood is pumped into the pulmonary artery. At the pulmonary artery, it is met ...
The foramen ovale is continuous with the ostium secundum, again providing for continued shunting of blood. The ostium secundum progressively enlarges and the size of the septum primum diminishes. Eventually, the septum primum is nothing more than a small flap that covers the foramen ovale on its left side. This flap of tissue is called the ...
Fossa ovalis (thigh), also called the saphenous opening; Fossa ovalis (heart), an embryonic remnant of the foramen ovale; See also. Fossa (disambiguation)
Before birth, it does not fuse with the septum intermedium, leaving a gap to form the foramen ovale. [1] Shortly after birth, it fuses with the septum primum to form the interatrial septum, and the foramen ovale is closed. [1] The fossa ovalis denotes the free margin of the septum secundum after birth.