Concept Check: Why Respire?

Opioids, such as fentanyl, act on receptors in the brain that control respiration in addition to pain receptors. As a result, opioid overdoses can be fatal as opioids result in severe respiratory depression and respiratory arrest in which the individual stops breathing. Under these circumstances how much net ATP is being generated per mole of glucose?

Panic attacks are typically associated with a greatly increased respiratory rate. If this persists for an extended period of time an individual may develop carpopedal spasms in which the wrist and ankle joints undergo uncontrollable sharp flexion. What is the most likely underlying physiology for the development of carpopedal spasm?

A 70 kg patient is in the ICU post-cardiac arrest and is undergoing cooling therapy in the hopes of preserving brain and end-organ function. If they are administered a 100 mL/kg/day infusion of balanced crystalloid fluids and have a urine output of 500 mL/day then what accounts for the difference between the infusion volume and the volume of urine output?