Which Side Are the Organs On?

Discussion Although externally vertebrates present with bilateral symmetry, this is not necessarily true internally for humans. Humans have a normal left-right asymmetry of their internal organs. For example, the right lung has 3 lobes and is slightly larger than the left lung with 2 lobes. The normal asymmetry is called situs solitus (SS). Complete reversal of the normal abdominal and thoracic organ positions is called situs inversus totalis (SIT). Variations on the laterality between situs solitus and SIT has been referred to by different names including situs ambiguous or heterotaxy. For this case, the term situs ambiguous (SA) will be used. Overall the incidence is 1 in 15,000 for all lateralization defects, with SIT being reported from 1 in 6,500-25,000. Laterality problems are associated with some specific syndromes and genes. Anatomic variations overall are very common and an illustrated atlas can be found here. Learning Point Such lateral anatomical variation may never cause any significant problems, but certainly has the potential to do so. Congenital heart defects, respiratory and hepatic problems are usually thought about first as they can cause acute life-threatening problems. However, patients may also have functional asplenia and increased risks of infection. Medical procedures may be more difficult to perform because of the differences in laterality, and imagine the surprise thoughts of the trauma surgeon who must also confront vast anatomical differences in an...
Source: PediatricEducation.org - Category: Pediatrics Authors: Tags: Uncategorized Source Type: news