7 December 2011Renal Physiology

Test # 3 Update on grading

Next Week in Physiology: Final ExamsMonday 9-noon for 8:30 sectionTuesday 2-5 for 10:30 sectionWednesday 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 andDiabetes 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 14.30 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 H2O reabsorption

Figure 14.31Normally, all filtered bicarbonate is “reabsorbed”

Figure 14.32This process is increased during metabolic acidosis

Excess H+ eliminated in urine bound to phosphate buffer.

Figure 14.331. Filtration2. Reabsorption3. Secretion4. 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)PaCO2 =30 mmHg, plasma pH = 7.47

Hyperventilating: ventilation in excess of metabolism to compensate for loss of alveolar surface area for diffusion of O2

Commensurate loss of CO2

RESPIRATORY ALKALOSIS

Renal compensation………retain H+ and eliminate HCO3

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Review 3 previous slides.