1
Explain with words and use diagrams to depict the 3 different kidney processes (or functions).
-Filtration: Pressure-driven process that moves water and solutes from the blood into the glomerus.
-Reabsorption: Moves essential solutes and water back into the bloodstream from the filtrate.
-Secretion: Moves toxins from the blood into the collecting ducts.
Explain how each of the FIVE factors influences the Glomerular Filtration Rate (GFR). If any one of them changes (increases/decreases), how would that affect GFR and why?
-More surface area, increased GFR
-Less surface area, decreased GFR
Permeability of Glomerular Capillaries
-If they are really leaky, leak faster, increased GFR
-If less leaky, leak slower, decreased GFR
Fluid/Blood Pressure in Glomerular capillaries
-If fluid pressure increases, GFR increases bc pushing blood through quicker
-If fluid pressure decreases, GFR decreases bc pushing blood through slower
Fluid Pressure in Nephron
-If nephron pressure increases, GFR decreases
-If nephron pressure decreases, GFR increases
Osmolarity of Glomerular capillaries
-If osmolarity increases, GFR decreases
-If osmolarity decreases, GFR increases
If a person has higher than normal levels of protein in the urine this indicates what about the filtration barrier?
The glomerular filtration barrier is damaged, allowing protein leak in that isn't supposed to. This can lead to a sign of a kidney disease. These proteins should be retained in the blood.
People with untreated diabetes mellitus are unable to prevent starvation depsite the large amounts of glucose surrounding their cells; as if that isn't bad enough, dehydration is also a problem due to a large volume of urine output. Explain why there is glucose in the urine of diabetics, why glucose is nor present in the urine of non-diabetic people, and why diabetes have large volume of urine output?
There is glucose in urine of diabetics because glucose reabsorption requires transporters, which are limited in numbers. The very high glucose levels in the blood of diabetics use ALL the transporters and the glucose that can't get to a transporter remains in the nephron and flows into the urine. There is not glucose in a non-diabetics urine because the kidneys effectively reabsorb almost all the glucose filtered from the blood back into the bloodstream during reabsorption process. Diabetics have large volume of urine output because water is reabsorbed and stays in the nephron and/or moves from the blood/body into the nephron where osmolarity is high. This water movement into the nephron increase fluid volume in the nephron and increases urine volume.
True or False
Na+ absorption is passive and requires an osmotic gradient
False
True or False
Water reabsorption occurs as a result of increases interstital fluid osmolority.
True
True or False
Having a genetic defect in the Na+/K- ATPase of your nephron cells that causes the pump to work much slower or not at all will cause a decrease in the osmolarlity/osmolarity in the nephron tubule lumen.
True or False
Fluid pressure in the nephron drives water reabsorption.
False, Na+ absorption drives water reabsorption
Explain the process of water reabsorption and sodium reabsorption
-Na+ in the nephron diffuses into the ISF (interstital fluid) space through the nephron tubule cell by Na+/K- pumps from ATP
-Increase ISF osmolarity and decrease tubule osmolarity
-Osmotic gradient = ISF osmolarity > Tubule osmolarity > Osmosis of water > Nephron tubule to ISF
*Na+ moves into the ISF then blood stream and wherever Na goes water follows.
Complete the Osmoreceptor-ADH feedback system reflex diagram below that occurs following a water deficit.
Problem: Water deficit
-Increased extracellular osmolarity
-Increased ADH secretion
-Increased plasma ADH
-Increased H2O permeability in nephron tubles
-Increased H2O absorption
-Decreased H2O excretion
Anesthesia depresses the central nervous system's drive for breathing and causes hypoventilation. This can result in altered blood pH within minutes due to changes in arterial PCO2. Does PCO2 increase or decrease following anesthesia induced hypoventilation?
The PCO2 increases because the air is more acidic.
Does hypoventilation cause an increase, decrease, or no change in blood pH and H+ concentration in the extracellular fluid (ECF)?
Blood pH- decreases
ECF (H+)- increases
Does hypoventilation result in total, partial, or no change in HCO3- reabsorption and an increase, decrease, or no change in H+ secretion at the kidneys?
HCO3- reabsorption- no change
H+- increases
Does the kidney "fix" for this altered state result in more, less, or no change in HCO3- in the urine? As a result will the urine be acidic, basic, or neural?
No change in HCO3- in urine but it becomes more acidic
Following the "kidney" fix for this altered state (hypoventilation) is the blood pH increased, decreased, or not changed? Is the extra-cellular fluid H+ concentration increased, decreased, or not changed following a renal compensation for respiratory acidosis?
Blood pH- increases
ECF (H+)- Decreases
Describe an example of what we might do or what might happen to our bodies to cause metabolic acidosis. Then explain how this specifically causes the metabolic acidosis.
-Diarrhea: lose HCO3- in stool
-Diabetes use stored fat/protein for energy which leads to acid by products
-decrease HCO3- or increased H+ which causes acidosis.
Does the respiratory system increase or decrease ventilation to compensate for the metabolic increase?
Increases ventilation (faster & deeper), which leads to a decrease in PCO2
Does the change in respiratory ventilation increase, decrease, or not change arterial PCO2 levels?
Also during metabolic acidosis there is a huge drop in blood HCO3- due to the accumulated acid. Does this drop in HCO3- cause the amount of HCO3- being filtered to be greater than, less than, or equal to the amount of H+ ions secreted?
Less than the amount of H+ secreted
Does the difference between the amount of HCO3- being filtered and the amount of H+ ions secreted result in total or partial reabsorption of HCO3- ?
Total reabsorption of HCO3+
Total reabsorption of HCO3-
Following the "kidney" fix for metabolic acidosis, is the excreted urine acidic or basic? Does excreting urine with this type of pH make the blood pH more acidic or basic?
The excreted urine is acidic which makes the blood pH more alkaline (basic)