Which of the following reactions contributes the most to gas transport in systemic capillaries than in pulmonary capillaries? OA. Hb + O₂ -> HbO₂ OB. HbCO2 -> Hb + CO₂ OC. HbO2 -> Hb + 0₂ OD. HbCO2-> Hb + HCO3 OE. HbH -> Hb + H*

After finishing last in the gymnastics competition (they had to cut him free from the rings), it is now time for synchronised swimming. In order to be able to breathe under water, Marco has snuck in a balloon which he will breathe in and out of while submerged. Consider how the following parameters will change over time as he continues to re-breathe from the balloon. Ignore the pressure effects of the water on Marco and the balloon. Central chemoreceptor activity Minute ventilation Plasma pH Arterial PO2 [Choose ] ✓ [Choose ] Diameter of pulmonary arterioles Decrease No change Increase [Choose ] [Choose ]

in the conducting airways. This air is not available for gas exchange Question 46 What is hemoglobin saturation at altitude (assume high altitude) with a PO2 of 50 mmHg? O 55 83.5 O 97.5 O 100 Question 47

Internal respiration During internal respiration, the small amount of oxygen transported in dissolved plasma (1) quickly diffuses out of the plasma into interstitial fluid. Carbon dioxide diffuses into the blood and a small amount remains dissolved in the plasma (2). Most of the carbon dioxide continues into the red blood cell where some of it combines with hemoglobin (3) to form carbaminohemoglobin (4). Most carbon dioxide, however, combines with water (5) to form carbonic acid (6). This reaction is catalyzed by carbonic anhydrase. The carbonic acid then dissociates into hydrogen and bicarbonate ions (7). As bicarbonate ion concentration inside the red blood cell increases, bicarbonate ions diffuse out of the red blood cell into plasma (8) in exchange for chloride ions (9). Bicarbonate ions act as buffers within the plasma, controlling pH. Within the red blood cell, hydrogen ions (10) are buffered by hemoglobin (11). When hemoglobin binds hydrogen ions, it has a lower affinity for…