Physio/simple/renal

Front 1

What is respiratory acidosis?

Back 1

This can occur in advanced in advanced pulmonary disease, the lungs do not adequately remove excess CO2 and the blood becomes acidic because of CO2 buildup.

Front 2

How do the kidneys react to the the above scenario?

Back 2

The kidneys try to compensate by increasing its reabsorption of HCO3. If the insult is not too severe, there may be compensation for the acidosis, in which case both HCO3- and PCO2 will be elevated.
The increased bicarbonate often is accompanied by a reciprocal decrease in chloride.

Front 3

What is metabolic acidosis?

Back 3

It is the addition to the body of an acid, other than carbonic acid(excess aspirin ingestion, lactic acidosis, or diabetic ketosis), or the loss of bicarbonate from the body(severe diarrhea).

Front 4

How do the respiratory centers respond to this?

Back 4

They respond by increasing respiration, thereby driving off CO2, to a degree that the pCO2 may become subnormal, and the pH approaches normal.

Front 5

In respiratory alkalosis, which might occur with psychogenic hyperventilation, CO2 is blown off in excess. TRUE/FALSE

Back 5

TRUE. The kidneys compensate for the alkalosis by excreting more HCO3-.

Front 6

What happens in metabolic acidosis?

Back 6

There is an increase in plasma HCO3-. This may occur with excess ingestion of bicarbonate, with loss of stomach HCl through protracted vomiting.

Front 7

In metabolic alkalosis, what happens with the loss of H+?

Back 7

This drives the reaction to the right, with an increase in bicarbonate. With decreased respiratory activity, CO2 is retained during compensation.

Front 8

What is anion gap?

Back 8

It is a useful wayof distinguishing between various kinds of acidosis.
Anion gap=[Na+]-[Cl- + HCO3-]

Front 9

In order to maintain charge balance the concentrations of anions(negative ions) must = the concentration of cations(positive ions). TRUE/FALSE

Back 9

TRUE. The normal anion gap is only 8-12meq/L, the difference reflecting other plasma anions.

Front 10

What happens to the anion gap, as in cases of diarrhea?

Back 10

It remains normal in an acidosis that is due to simple HCO3 loss. This is because as a general principle[Cl-] increases to meet the drop in HCO3- anions, maintaining anionic balance.

Front 11

When does the anion gap become more significant?

Back 11

This occurs in various kinds of acidoses where there is an excess of certain kinds of anions(lactate in lactic acidosis; keto acids in diabetic and alcoholic ketoacidoses and starvation; phosphate, sulfate, and other organic acid ion accumulation in renal failure, salicylate poisoning in aspirin overdose; glycolate in ethylene glycol poisoning; lactate, formate and keto acids in methanol poisoning.

Front 12

Calcium is the most abundant of the body's minerals. TRUE/FALSE

Back 12

TRUE. When bound to the receptor protein calmodulin, calcium helps modulate the activities of many enzymes.

Front 13

What does parathyroid hormone do?

Back 13

It raises blood calcium levels. It promotes intestinal absorption of Ca++ by stimulaing the activation of vit D in the kidney to 1,25 dihydroxycholecalciferol, which directly promotes intestinal absorption of Ca++.

Front 14

Parathyroid hormone also increases renal tubular reabsorption of Ca++(in distal renal convoluted tubule) which also increases plasma calcium levels. TRUE/FALSE

Back 14

TRUE.

Front 15

Vit D in large amounts has a similar effect as parathyroid hormone, promoting bone breakdown. TRUE/FALSE

Back 15

TRUE. When present in small amounts it induces bone calcification, through its effect in increasing Ca++ uptake in the intestines and kidney.

Front 16

What is the working relationship between phosphate, Ca++ and Vit. D?

Back 16

Phosphate enters the blood with Ca++ when Vit. D promotes Cacium absorption in the intestine. bone breakdown and renal tubular Ca++ reabsorption.

Front 17

What is the relationship between parathyroid hormone and vit. D?

Back 17

To counterbalance this, PTH has an important effect opposite to that of vit. D. It inhibits renal reabsorption of phosphate, acting at the level of the proximal tubule.
Patients with renal disease may develop renal rickets through vit. D deficiency.

Front 18

What does calcitonin do?

Back 18

It acts the opposite of PTH. It causes bone uptake of Ca++ and reduces plasma Ca++ levels.

Front 19

What is the relationship between pH and calcium?

Back 19

Decreased pH(increased H+) decreases Ca++ binding to plasma proteins, since H+ competes for binding sites.
More calcium binds to protein in alkalosis, and in alkalosis(hyperventilation), the patient may be subject to tetany from hypocalcemia.

Front 20

Magnesium is an important participant in reactions that involve ATP. TRUE/FALSE

Back 20

TRUE. Excess is associated with CNS toxicity.

Front 21

Chromium enhances the effect of insulin. TRUE/FALSE

Back 21

TRUE. A defiency results in defective glucose metabolism. Excess is via inhalation of chromium dust, which may lead to pulmonary carcinoma.

Front 22

In which vitamin is cobalt found?

Back 22

Vit. B12.

Front 23

Where is Copper found?

Back 23

It is part of a number of enzymes, including cytochrome oxidase and lysyl oxidase(important in collagen cross linking).
Deficiency results in anemia and mental retardation. Excess results in liver disease and copper cataracts. These occur in Wilson's disease in which excess copper deposits in the brain, liver, cornea, lens and kidney.

Front 24

Iodide is part of the hormone thyroxine. TRUE/FALSE

Back 24

TRUE. Deficiency results in hypothyroidism, excess, hyperthyroidism.

Front 25

What is hemochromatosis?

Back 25

Excess iron will result in this. Abnormal iron deposits may damage the liver, pancreas and other tissues.

Front 26

What is manganese used for?

Back 26

It is needed to activate a variety of enzymes, including enzymes involved in the synthesis of glycoproteins, proteoglycans and oligosaccharides.
Excess may result in Parkinson's disease.

Front 27

Molybdenum is an important component of certain enzymes(xanthine oxidase). TRUE/FALSE

Back 27

TRUE.

Front 28

What is the potential function of nickel?

Back 28

It may stabilize the structure of nucleic acids and cell membranes. excess may result im pulmonary carcinoma.

Front 29

Where is selenium found?

Back 29

It is part of the enzyme glutathione peroxidase, which like vit. E acts as an antioxidant.

Front 30

Where is Silicon found?

Back 30

It is associated with many mucopolysaccharides and may be important in the structuring of connective tissue.

Front 31

Is Zinc found in enzymes?

Back 31

It is a component of many enzymes, including lactate dehydrogenase and alkaline phosphatase.
A deficiency is associated with poor wound healing, hypogonadism, decreased taste and smell.

Front 32

What is creatinine, and Urea?

Back 32

creatinine originates from muscle creatine breakdown, and urea comes from protein catabolism.
These substances are moderately accurate indicators of renal function. Yet, they are subject to change due to endogenous and exogenous influences, and therefore are not the most accurate way to measure renal function.

Front 33

What is the GFR?

Back 33

This is a more accurate measure of renal function.It is simply the amount of fluid that filters through the glomerular membrane per unit of time.
The GFR depends on the filtration pressure at the level of the glomerulus, but also on the permeability of the glomerular membrane and the surface area of the glomerular membrane.
GFR= (net filtration pressure) X (surface area) X (hydraulic permeability).

Front 34

Is ther a more accurate way to measure GFR?

Back 34

Yes. Put differently,GFR= (Urine creatinine conc.) X (Urine volume collected/24hr)/(plasma creatinine conc).
No significant amounts of creatinine are reabsorbed or secreted. This is why creatinine instead of other molecules is chosen.

Front 35

The glomerular conc of filtered creatinine is about the same as the plasma conc. of creatinine, as there is free diffusion across the glomerular membrane. Therefore: What formula might accurately express this relationship?

Back 35

(Mass of creatinine filtered/time)=(Plasma conc. of creatinine) X (Volume of glomerular fluid. filtered/time) = Mass of creatinine excreted/time.

Front 36

What is inulin?

Back 36

This molecule may be used to test GFR, since creatinine does get minimally secreted, whereas inulin is not secreted at all.
Inulin, however, does not occur naturally and has to be continuously perfused via I/V to maintain its plasma concentration throughout the test.

Front 37

What is clearance?

Back 37

Clearance is the volume of plasma that is actually completely cleansed of a particular substance in the urine.
Clearance(of substanceY) =(Urine conc. of substance Y) X (Urine volume collected/24hr)/(Plasma conc. of substance Y).