State the full name of HIV.
Once HIV has been transmitted, diagnosing the infection early and treating it with anti-retroviral therapy (ART) can help limit the spread of the pathogen and prevent HIV/AIDS. Suggest why giving ART to people who have developed HIV/AIDS may reduce the total number of deaths from infectious diseases, such as cholera, TB and malaria.
Studies indicate that people infected with HIV may face a greater risk of heart disease. One cause of heart disease is narrowing of the lumen of one or both of the main coronary arteries. A coronary artery bypass graft (bypass graft) is an operation in which healthy blood vessels are used to divert blood around diseased parts of the coronary arteries. The main vessel selected for a bypass graft is the internal thoracic artery. Fig. 6.1 shows an external view of the heart to illustrate a double bypass graft. The blood vessels used in the bypass graft in Fig. 6.1 are the great saphenous vein from the leg and the internal thoracic artery.
Draw a cross (X) on Fig. 6.1 to indicate an area of the right coronary artery that has been bypassed.
After surgery, the wall of the great saphenous vein thickens. Suggest and explain why it is important for the wall of the vein to become thicker after surgery.