While the presence of Islam in West Africa dates back to eighth century, the spread of the faith in regions that are now the modern states of Senegal, Gambia, Guinea, Burkina Faso, Niger, Mali and Nigeria, was in actuality, a gradual and complex process.
Hypoventilation is a condition that arises when air entering the alveoli, small air sacs in the lungs that are the site of respiratory gas exchange, is reduced. This causes levels of oxygen to decrease and the levels of carbon dioxide to increase.
Manifestations of hypoventilation are seen during the first 30 minutes of oxygen therapy. The patient's color improves (from ashen or gray to pink) because of an increase in the PaO2 level before the apnea or respiratory arrest occurs from slower and shallow respirations.