Fossa ovalis (heart)

Source: Wikipedia, the free encyclopedia.
(Redirected from
Limbus of fossa ovalis
)
For the fossa ovalis of the thigh, see saphenous opening.
Fossa ovalis
right ventricle opened. Fossa ovalis is labeled in the right atrium.
Details
PrecursorForamen ovale
Identifiers
Latinfossa ovalis cordis
TA98A12.1.01.005
TA23965
FMA9246
Anatomical terminology]

The fossa ovalis is a depression in the

left atrium. The fossa ovalis is the remnant of a thin fibrous sheet that covered the foramen ovale during fetal
development.

Function

During fetal development, the foramen ovale allows blood to pass from the right atrium to the

left atrium; it is the remains of the fetal aperture the foramen ovale between the two atria
.

Closure

Almost immediately after the infant is born, the foramen ovale and

enzyme synthesis). The foramen ovale becomes the fossa ovalis as the foramen closes while edge of the septum secundum in right atrium becomes anulus ovalis, so the depression beneath it becomes the fossa ovalis.[2][unreliable medical source?
] This enables respiration and circulation independent from the mother's placenta.

With the child's first breath, the lung sends

oxygenated blood to the left atrium. As a result, pressure in the left atrium is higher than that of the right, and the increased pressure holds the interatrial flap (which covers the foramen ovale) shut, therefore closing the foramen ovale as well.[2] In normal development, the closed foramen ovale fuses with the interatrial wall. During the first breath, vasoconstriction causes the ductus arteriosus to close, and during adult years, tissue occludes what once was the ductus arterious, creating the ligamentum arteriosum.[3]

Clinical significance

Aneurysm

Aneurysms can occur in adulthood if the foramen ovale is not closed correctly. An aneurysm happens when an artery becomes enlarged in a localized area due to weakening of the arterial wall.[4]

When this type of aneurysm occurs in the area of the fossa ovalis, an enlarged pouch is formed. This pouch can protrude into the right atrium or the left atrium. The cause of this aneurysm is the result of abnormal, increased pressure within the heart. Even if the foramen ovale does seal shut, an aneurysm may occur, usually on the side of the right atrium. If the aneurysm stretches too far, it can narrow the opening of the

coronary heart disease, as well as diseases of the aortic valve or mitral valve
. Surgery may be useful in helping to cope with the aneurysm.

Patent foramen ovale

Main article:
Patent foramen ovale

If the atrial septum does not close properly, it leads to a patent foramen ovale (PFO). This type of defect generally works like a flap valve, opening during certain conditions of increased pressure in the chest, such as during strain while having a bowel movement, cough, or sneeze. With enough pressure, blood may travel from the right atrium to the left. If there is a

heart attack.[6]

See also

This article uses anatomical terminology.

References

  1. ^
    PMID 16256883
    .
  2. ^ a b Johnson, Donna. "What is the Fossa Ovalis?". Conjecture Corporation. Retrieved 16 March 2012.
  3. ^ Dryden, Richard. "Respiratory system". Retrieved 16 April 2012.
  4. PMID 7608452
    .
  5. PMID 12826292
    .
  6. ^ "Patent Foramen Ovale". The Cleveland Clinic. Retrieved 15 April 2012.

External links

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