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.
Because primates are suspected of being the source of HIV, AIDS is considered a zoonosis, an infection that is shared by humans and other vertebrate animals. Genetic studies of a pandemic strain of HIV, known as HIV-1 group M, have indicated that the virus emerged between 1884 and 1924 in central and western Africa.