Interatrial foramen

Interatrial Foramen is a structure in the heart that allows communication between the two atria. It is an essential part of the fetal circulation, but normally closes shortly after birth.

Anatomy

The interatrial foramen, also known as the foramen ovale, is located in the septum between the right and left atria. It is surrounded by a thin, fibrous ring and is covered by a flap of tissue that acts as a one-way valve, allowing blood to flow from the right atrium to the left, but not in the reverse direction.

Function

In the fetus, the interatrial foramen allows oxygenated blood from the placenta to bypass the non-functioning lungs and go directly to the systemic circulation. This is crucial for fetal survival, as the lungs are not yet capable of oxygenating the blood. After birth, when the lungs begin to function, the pressure in the left atrium increases, causing the flap to close and seal the foramen.

Clinical significance

In some individuals, the interatrial foramen fails to close completely after birth, a condition known as a patent foramen ovale. This can potentially allow blood clots to pass from the right side of the heart to the left, bypassing the lungs and leading to a stroke or other serious complications.

See also

• Heart
• Atria (heart)
• Foramen ovale (heart)
• Patent foramen ovale