Scenario C: Bill is a healthy guy who has gotten lost in the wilderness, he's been climbing a cliff to try to get home. His legs (and some other muscles) are burning huge amounts of ATP (total metabolic rate has increased to around 7 times basal). His cardiac output has risen to five times the basal rate. His respiratory rate has increased from 10 breath/min at rest to about 20 breath/min. His tidal volume has risen from 700 ml at rest to about 1525 ml. He weighs about 70 kg (~150 lb). If no other control actions or reflexes occur, what will be the effect on (compared to rest values) 49 2 ) PO at most alveoli: a) increased by 30 mmHg, b) largely unchanged, c) decreased by 30 mmHg 50 2 ) PO at the left atrium: a) increased by 30 mmHg, b) largely unchanged, c) decreased by 30 mmHg 51 2 2 ) PO at the right ventricle (mixed venous PO ): a) increased by 10 mmHg, b) largely unchanged, c) decreased by 10 mmHg 52) Oxygen delivery to the systemic tissues a) decreased by 20% b) largely unchanged c) increased by 20% d) increased proportionally to increase in cardiac output e) increased proportionally to increase in metabolism