2 Maintenance oft balance OUTSIDE At rest Water channel Cell membrane embrane Em=-75 mv) OUTSID Immediately after INSIDE OUTSIDE NSIDE
2.Maintenance of K+ balance
intake ECE ICF K+ K+ 3.5~5.5mmoL pump channe 140~160mmoL kidney Gi tract Direction oft shifting 90% Skin? Maintenance oft balance
Direction of K+ shifting 140~160mmol/L 3.5~ 5.5 mmol/L ECF ICF K+ K+ Maintenance of K+ balance intake kidney GI tract 90% Skin? 10% channel pump
(1) The control of K transfer between intra- extracellular compartments The Na*/KATPase(membrane pump Permea bility of ion channels
(1) The control of K+ transfer between intra- & extracellular compartments • The Na+ /K+ATPase (membrane pump ) • Permeability of ion channels
ECF ICF K pump channel Insulin, B-adrenergic agonist, ADS, 「K+s」, exercise,pH, ECF oSmolality↑ K+ shifts between icf and ecF
ECF ICF K+ K+ shifts between ICF and ECF Insulin, β-adrenergic agonist, ADS, [K+ ]s↓, exercise, pH ↓, ECF osmolanity ↑ channel pump
(2) Regulation of renal K excretion
(2) Regulation of renal K+ excretion ?