PHYSIO- Lab Exam FINAL

Glomerular Filtration

Removal of plasma substances by a non-selective pressure gradient between the blood and the nephron.

Afferent → Glomerulus → Efferent

What effect does increasing afferent arteriole diameter have on pressure in the glomerulus?

What effect does this change in pressure have on the GFR? Why?

What affect does this change in GFR have on urine production? Why?

How about vice versa?

Afferent arteriole UP → Pressure UP → GFR UP → Urine Production UP

Afferent arteriole DOWN→ Pressure DOWN→ GFR DOWN→ Urine Production DOWN

What effect does increasing efferent arteriole diameter have on pressure in the glomerulus?

What effect does this change in pressure have on the GFR? Why?

What affect does this change in GFR have on urine production? Why?

How about vice versa?

Efferent arteriole UP → Pressure DOWN → GFR DOWN → Urine prod. DOWN

Efferent arteriole DOWN → Pressure UP → GFR UP → Urine prod. down

What health conditions might develop if GFR is too high? What about too low?

Too high: dehydration (too much secretion)

Too low: Edema (not enough being secreted, build up in flesh)

What effect does increasing BP have on GFR and urine output? How about decreasing?

BP UP = GFR/Urine UP b/c net pressure UP

BP DOWN = GFR/Urine down b/c the kidney tries to retain blood volume by reabsorbing more and filtering less in respond to BP lowering

What is Net Filtration Pressure?

Blood hydrostatic pressure (BP) + Capsular Hydroid pressure

What effect does closing the valve have on GFR and urine prod.? What condition does closing the valve (collecting duct) simulate?

GFR DOWN b/c pressure isn’t being regulated +X urine production because filtrate can’t exit at all

Blockage of the collecting duct simulates kidney stones or a tumor.

When BP drops, what does the afferent arteriole do to compensate? How about the efferent artiole?

BP DOWN = Afferent Arteriole DILATES/ Efferent Arteriole CONSTRICTS

When BP rises, what can the afferent arteriole do to compensate? How about the efferent arteriole?

BP DOWN = aff. arteriole CONSTRICT, eff. arrteriole DILATE

As you increase the concentration of ISF, what happens to the urine volume? What happens to urine concentration? Explain why.

ISF concentration UP (returning to the blood) = Urine volume DOWN and Urine concentration UP b/c water reabsorption is increasing and leaving less water in the urine

What effect does ADH have on the kidney?

ADH ~ water reabsorption UP in collection duct

Predict what would happen to urine volume and urine concentration if ADH was not added. Why?

Without ADH, the levels of urine volume and concentration would be unchanged.

What happens to the concentration of glucose in the renal capsule as you add glucose carriers? Why?

An increase in glucose carriers doesn’t affect glucose uptake as reabsorption does not occur there, only filtration.

What happens to the concentration of glucose in the bladder as you add glucose carriers? Why?

An increase in glucose carriers leads to an increase in the bladder as glucose is leaving in a higher rate.

A person with diabetes is unable to absorb glucose into most of their body’s cells. How will this affect glucose concentration and how would that affect glucose reabsorption?

glucose concentration goes UP b/c it can’t be absorbed → cells can’t absorb all the glucose so it ends up in urine (sweet smell)

How does ADH affect urine volume and urine concentration?

ADH = urine volume DOWN and urine concentration UP b/c water reabsorption

Does Aldosterone affect urine volume and/or concentration? How?

Aldosterone = urine volume DOWN b/c it promotes water absorption through salt reabsorption.

Aldosterone = urine concentration UNAFFECTED b/c reabsorption of salt and water in equal parts

Describe the changes in PCO2 and pH during hyperventilation. What is the name of the condition caused by the change in pH? Explain.

Hyperventilation = PCO2 DOWN, pH up → Respiratory Alkalosis

During the hyperventilation/normal run, why was there a pause ?

Apnea vera = retaining CO2 for compensation

Describe the changes in PCO2 and pH during rebreathing. Explain why these changes occur.

Rebreathing = PCO2 UP, pH down b/c compensation (re-inhaling CO2)

Explain why the amplitude of the waves during rebreathing increased.

Slowing down of breathing to retain CO2 → deeper breaths → worsens problems

Describe the changes in PCO2 and pH occur during Hypoventilation. What is the name of condition caused by the change in pH? Explain why.

Hypoventilation = PCO2 UP, pH DOWN → CO2 build up and Respiratory Acidosis

How does respiratory alkalosis affect urine pH. Explain how this change occurs, specifying what the kidney is secreting and reabsorbing.

Respiratory Alkalosis = urine pH UP b/c HCO3- being secreted to rebalance pH (H+ being reabsorbed)

How respiratory acidosis affect urine pH? Explain how this change occurs, specifying what the kidney is secreting and reabsorbing.

Respiratory acidosis = urine pH DOWN b/c H+ is being secreted to help rebalance the pH (and reabsorbing bicarb)

How does increased metabolism affect blood pH? What is the condition called?

Metabolic Acidosis = pH down

How does increase metabolism affect respiratory rate? Explain how this change compensates for the increased metabolism.

Metabolic Acidosis → RR UP to get rid of CO2

How does decreased metabolism affect blood pH? What’s the condition called?

Metabolic Alkalosis = blood pH UP b/c less CO2 made from metabolism

How does decreased metabolism affect respiratory rate? How does this change compensate for the decreased metabolism.

Metabolic acidosis = RR UP → CO2 UP