Lecture 8

Question 1

What is the kidneys purpose?

Answer 1

Excrete waste products
Retain desirable solutes
Maintain pH
Maintain osmolality -> maintain BP

Question 2

Glomerulus

Answer 2

filters larger particles: cells and Albumin
Small particles continue for possible reabsorption or excretion

Question 3

Proximal Convoluted Tubules

Answer 3

“pumps”, by active transport, most solutes back into the blood

Question 4

Loop of Henle

Answer 4

reabsorption of H2O
increasing osmotic pressure along the loop -> causes H2O to be reabsorbed
Makes urine more concentrated

Question 5

Distal Convoluted Tubule

Answer 5

final adjustments of electrolytes and acid/base by HCO3-1

Question 6

Collecting Ducts

Answer 6

also reabsorbs more water

Question 7

Glomerular Filtration Rate

Answer 7

1500 mL/min of blood into:
125 mL/min (Small stuff continues on to be further “filtered” )
1375 mL/min returned to circulation with the “big stuff”

Question 8

Renal Threshold

Answer 8

the maximum rate that it can be reabsorbed

Question 9

When can’t substances be reabsorbed in Proximal Convoluted Tubules?

Answer 9

When substances have concentrations larger than the RT

Question 10

Urea

Answer 10

dominant waste product found in urine
the form of N from amino acids that are degraded
~ 50% gets reabsorbed by the tubules- the rest is reabsorbed

Question 11

Blood Urea Nitrogen (BUN)

Answer 11

Largest N containing component of blood besides protein
Produced in breakdown of amino acids

Question 12

Azotemia

Answer 12

High levels of urea

Question 13

Pre-renal azotemia

Answer 13

Reduced renal blood flow
High protein diets
Protein catabolism

Question 14

Protein catabolism

Answer 14

proteins -> amino acids -> urea + carbohydrates
Performed when energy stores are low

Question 15

Renal azotemia

Answer 15

kidney failure

Question 16

Post-renal azotemia

Answer 16

obstruction of urine flow, out of kidneys

Question 17

Creatine phosphate

Answer 17

an energy source like ATP
CP + ATP lasts for about 10 seconds of activity

Question 18

Where is creatine created?

Answer 18

The liver
arginine + lysine + methionine -> creatine

Question 19

What happens when creatine is transported to cells?

Answer 19

Becomes Creatine Phosphate

Question 20

When the phosphate is removed from Creatine Phosphate what happens?

Answer 20

CP becomes creatinine

Question 21

What is done with Creatinine?

Answer 21

Excreted into plasma
Filtered through kidneys

Question 22

Diagnostic Value Creatinine

Answer 22

High serum or low urine levels = kidney not removing creatinine
reflects problems with glomerular function

Question 23

BUN/Creatinine ratio normal range

Answer 23

10-20 mg/dL