7 December 2011 Renal Physiology Test # 3 Update on grading Next Week in Physiology: Final Exams Monday 9-noon for 8:30 section Tuesday 2-5 for 10:30 section Wednesday 9-noon for 9:30 section Friday Class: Lock in to Exam Day See old tests for 20 minutes at start of Friday’s class. Your only access to old tests.

a Which segment impermeable to water? Which segment has variable permeability to water? Which segments are under hormonal control?

Reabsorption and secretion in proximal tubule is NOT under hormonal control. Primary active transport of Na+ establishes a gradient for reabsorption of glucose, amino acids, etc. Reabsorption and secretion in DCT & CD is under hormonal control. Hormones that act here: ANH, ADH, Aldosterone. Here, reabsorption of Na+ is linked to the secretion of K+. Transport Maximum and Diabetes mellitus

Reabsorption and secretion in proximal tubule is NOT under hormonal control. Primary active transport of Na+ establishes a gradient for reabsorption of glucose, amino acids, etc. Reabsorption and secretion in DCT & CD is under hormonal control. Hormones that act here: ANH, ADH, Aldosterone. Here, reabsorption of Na+ is linked to the secretion of K+.

Effect of Aldosterone: insertion of more Na+K+ATPase into basolateral membrane Effect: Increase Na+ reab and Increase K+ Secretion

Figure Apply this information to each of the three Test Beverages used in the Urinalysis Lab! Cell in the adrenal cortex that respond to AII are also receptors for plasma K+ concentration. Sodium reabsorption and potassium secretion are coupled.

Effect of ADH: insertion of more aquaporins in the membranes Effect: Increase H 2 O reabsorption

Figure Normally, all filtered bicarbonate is “reabsorbed”

Figure This process is increased during metabolic acidosis Excess H+ eliminated in urine bound to phosphate buffer.

Figure Filtration 2.Reabsorption 3.Secretion 4.Metabolism This process is increased during metabolic acidosis Metabolism of glutamine in tubular cells generate bicarbonate buffer.

Who Cares?

Loss of HCl in vomitus would be compensated by…….. Changes in ventilation after you vomit?

Who Cares?

Father-in-law with emphysema (respiratory case studies lab) PaCO 2 =30 mmHg, plasma pH = 7.47 Hyperventilating: ventilation in excess of metabolism to compensate for loss of alveolar surface area for diffusion of O 2 Commensurate loss of CO 2 RESPIRATORY ALKALOSIS Renal compensation……… retain H+ and eliminate HCO 3 - Review 3 previous slides.