Longitudinal fissure Longitudinal fissure The longitudinal fissure (or cerebral fissure, median longitudinal fissure, or interhemispheric fissure) is the deep groove that separates the two hemispheres of the vertebrate brain. The medial surfaces of the two hemispheres are as similarly convoluted by gyri and sulci as is the outer surface of the brain. It is thought that a majority of existing animals, including Homo sapiens, have evolved from a common wormlike ancestor that lived around 600 million years ago, called the urbilaterian. A bilaterian animal is one that has symmetrical left and right body halves. While it is still debated whether this species
History of beliefs about the human body is important to understanding histories of coercion and control, sex and gender, and other important but culturally varied aspects of human experience. Another prominent voice in the field at the same time was Caroline Walker Bynum, whose 1988 "Holy Feast and Holy Fast" became a landmark study. Both Bynum and Porter noted that during the 1980s Western history of the body research drew on post-structuralist thought, such as Michel Foucault's ideas of biopolitics and biopower, which emphasised that state power is not abstract, but exercised through and over human bodies. But both expressed a concern that research was focusing too