SITUS INVERSUS

Imagine as a doctor you told your patient to go for a routine chest or abdominal x-ray. He or she comes back with the result,you place it in front of illuminated background and you are startled. At first you think you are having problems with your vision or you placed the x-ray film incorrectly. But then after pausing and trying it the other way you discover that there is nothing wrong with your vision and that you placed the x-ray film correctly, you are witnessing a rare condition. All organs that should be on the right are on the left and all organs that should be on the left are on the right. Your patient is fine with no symptoms, just came for a yearly health check-up. If you don't already know about this rare condition don't panic and you are not going mad or forgotten all your anatomy.

 It's SITUS INVERSUS VISCERUM.

Situs inversus (also called situs transversus or oppositus) is a congenital condition in which the major visceral organs are reversed or mirrored from their normal positions. The normal arrangement is known as situs solitus. In other rare cases, in a condition known as situs ambiguus or heterotaxy, situs cannot be determined.

The term situs inversus is a short form of the Latin phrase "situs inversus viscerum", meaning "inverted position of the internal organs". Dextrocardia(the heart being located on the right side of the thorax) was first seen and drawn by Leonardo da Vinci in 1452–1519, and then recognised by Marco Aurelio Severino in 1643. However, situs inversus was first described more than a century later by Matthew Baillie.

Situs inversus is thought to be present in 0.01% of the population, or a 1 in 10,000 chance.

The condition affects all major structures within the thorax and abdomen. Generally, the organs are simply transposed through the sagittal plane. The heart is located on the right side of the thorax, the stomach and spleen on the right side of the abdomen and the liver and gall bladder on the left side. The left lung is trilobed and the right lung bilobed, and blood vessels, nerves, lymphatics and the intestines are also transposed.

If the heart is swapped to the right side of the thorax, it is known as situs inversus with dextrocardia or situs inversus totalis. If the heart remains on the normal left side of the thorax, a much rarer condition (1 in 22,000 of the general population), it is known as situs inversus with levocardia or situs inversus incompletus.

Situs inversus is generally an autosomal recessive genetic condition.

Many people with situs inversus totalis are unaware of their unusual anatomy until they seek medical attention for an unrelated condition. The reversal of the organs may then lead to some confusion, as many signs and symptoms will be on the atypical side. For example, if an individual with situs inversus develops appendicitis, they will present to the physician with lower left abdominal pain, since that is where their appendix lies. 

THE HUMAN BODY IS INTERESTING AND AMAZING ISN'T IT?