Mesoderm lining the coelom forms mesothelium. Separation of Peritoneal and Pleural Cavities: In the adult, peritoneal and pleural cavities are separated by the diaphragm. The diaphragm isformed by a septum transversum, paired pleuroperitoneal folds, and somatic mesoderm.
HIV Myth 2: 'HIV and AIDS Are the Same Thing'. Absolutely not. HIV is the virus that infects a person and attacks the immune system. AIDS is the disease that develops later in people with HIV that remain untreated or don't respond to treatment.
This name was later changed to HIV (human immunodeficiency virus). For many years scientists theorized as to the origins of HIV and how it appeared in the human population, most believing that HIV originated in other primates. Then in 1999, an international team of researchers reported that they had discovered the origins of HIV-1, the predominant strain of HIV in the developed world. A subspecies of chimpanzees native to west equatorial Africa had been identified as the original source of the virus.