Possible points for measuring the heart rate are: 1  The ventral aspect of the wrist on the side of the thumb (radial artery). 2  The ulnar artery. 3  The neck (carotid artery). 4  The inside of the elbow, or under the biceps muscle (brachial artery). 5  The groin (femoral artery). 6  Behind the medial malleolus on the feet (posterior tibial artery).
HIV is a member of the genus Lentivirus, part of the family Retroviridae. Lentiviruses have many morphologies and biological properties in common. Many species are infected by lentiviruses, which are characteristically responsible for long-duration illnesses with a long incubation period.
HIV mutates very readily resulting in the formation of many different strains of HIV, even within the body of a single infected person. Based on genetic similarities, the numerous virus strains may be classified into types, groups and subtypes. There are two types of HIV: HIV-1 and HIV-2: Both types are transmitted by sexual contact, through blood, and from mother to child, and they appear to cause clinically indistinguishable AIDS. HIV-1 is related to viruses found in chimpanzees and gorillas living in western Africa, while HIV-2 viruses are related to viruses found in sooty mangabeys.