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 fear, coupled with many other reasons, means that lots of people falsely believe: 1  HIV and AIDS are always associated with death. 2  HIV is associated with behaviours that some people disapprove of (such as homosexuality, drug use, sex work or infidelity) 3  HIV is only transmitted through sex, which is a taboo subject in some cultures.