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.
HIV/AIDS. HIV Risk and Prevention. In the United States, HIV is mainly spread by having sex or sharing syringes and other injection equipment with someone who is infected with HIV. Substance use can contribute to these risks indirectly because alcohol and other drugs can lower peopleâs inhibitions and make them less likely to use condoms.