Alveolus; low, blood capillaries of alveolus; high; causing the carbon dioxide to diffuse from the blood capillaries into the alveolus

98% of oxygen combines with hemoglobin to form oxyhemoglobin. 2% oxygen is transported as a dissolved gas in the blood plasma

Oxygen diffuses from the alveoli into blood capillaries and combine with hemoglobin to form oxyhemoglobin. Until it reaches the body cells, oxyhemoglobin dissociates and oxygen enters the body cells

Blood (partial pressure of oxygen is high), body cells (partial pressure of carbon dioxide is high), causing the oxygen to diffuse into body cells, carbon dioxide diffuses into blood capillaries

70% of carbon dioxide is carried in the form of bicarbonate ions, 23% of carbon dioxide forms carbaminohemoglobin, and 7% is carried in the form of carbonic acid

Bicarbonic acid is formed in blood cells. Bicarbonic acid is broken down into bicarbonate ions and hydrogen ions. Bicarbonate ions are transported to the lungs

Bicarbonate ions recombine with hydrogen ions to form carbonic acid. Carbonic acid is broken down into water and carbon dioxide. Carbon dioxide is eliminated during exhalation

Depends on the partial pressure difference between two areas

The gas diffuses from an area where its partial pressure is higher to an area where its partial pressure is lower, which is down a partial pressure gradient