PHSI 208 Lecture 48: M18 Renal System 3-1
Document Summary
Aldosterone also plays a critical role in k+ homeostasis (enhances secretion in p cells) Plasma k+ needs to be maintained within a narrow range (3. 5-5 mm) Alteration in body k+ levels affects the resting membrane potential of all cells. Particularly important in excitable tissues such as the heart or skeletal muscles. Can lead to life threatening arrhythmias in the heart. Disturbances in k+ balance may result form kidney dysfunction, eating disorders, loss of. K+ in diarrhea or use of diuretics that prevent kidneys from properly reabsorbing k+ Decreased blood volume (baroreceptor and renin-angiotensin system) Behavioural mechanisms for na+ intake: driven by 2 factors: aldosterone and angii, also in the hypothalamus near region responsible for thirst. The cv system responds to changes in blood volume, the renal system responds to changes in blood volume and/or osmolarity, and behavioural mechanisms respond to both. Normally can be kept within a narrow range but under certain circumstances becomes out of balance.
