07 CO2

• CO2 stored as HCO3 to be transported to lungs

Bohr Effect

• conversion produces H+ ion that binds to globin chain to form HHb

• instead of dropping from 100 to 75% at tissue PO2 50 mmHg, drop to 50%, better unloading
• Bohr effect helps unload O2 via H ion binding to Hb

Cl Shift

• high bicarb inside cell diffuse out, in exchange for Cl

Haldane

• x: level of CO2
• y: amount CO2 bound to Hb
• purple line: normally, more PCO2 in blood = more bound to Hb
• in reality, blue line: even more bound to Hb at low O2 level

• Bohr for O2

High Altitude

• small box: someone living at high altitude

• mild polycythemia

Exercise

• arterial side maintain normal rate: not hypoxic or hypercapnea

Cerebral blood flow

• cerebral vasodilator
• left, O2: at normal range, O2 does not change cerebral blood flow much
• right, CO2: at normal range, powerful effect on blood flow

Breathing

• CO2 in blood stream major stimulus, not O2
• PNS chemoreceptor: only kick in under severe hypoxia, normally CNS working

• hypoxemia stimulate respiratory rate, can get low with O2 = high CO2, confusion

• in hospital on ventilation, O2 can make O2 saturation high and mask hypoventilation
• put on ventilator

• hypo ventilating, CNS symptoms