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.
In 1999 an international team of genetic scientists reported that the strain of HIV-1 responsible for most cases of AIDS can be traced to a closely related strain of virus, called simian immunodeficiency virus (SIV), that infects a subspecies of chimpanzee (Pan troglodytes troglodytes) in W central Africa.