Lecture 6- Renal Physiology

Question 1

What are some key functions of the kidneys

Answer 1

maintaining overall fluid balance

regulating and filtering minerals from blood

filtering waste materials from food, medications, and toxic substances

creating hormones that help produce red blood cells, promote bone health, and regulate blood pressure

Question 2

What are the kidneys roles in regulating fluid/electrolyte balance?

Answer 2

excrete or conserve salt and water;

control body pH, and

free the body of waste products of metabolism.

Question 3

What is the purpose of the glomerulus?

Answer 3

This is a cluster of capillaries responsible for blood filtration and is composed of a tuft of capillaries whose endothelial cells are interconnected with specialized renal visceral epithelial cells, called podocytes, and with mesangial cells.

Question 4

Bowman Capsule

Answer 4

The remaining fluid, called capsular urine, passes through the Bowman capsule into the renal tubules.

Question 5

What does the Proximal convoluted tubule, loop of henle, distal convoluted tubule do

Answer 5

Proximal convoluted tubule.This section absorbs water, sodium, and glucose back into the blood.

Loop of Henle.This section further absorbs potassium, chloride, and sodium into the blood.

Distal convoluted tubule.This section absorbs more sodium into the blood and takes in potassium and acid.

Question 6

Purpose of urinalysis test

Answer 6

screens for the presence of protein and blood in the urine.

Infection increases urine protein, but so does a heavy physical workout. Your doctor may want to repeat this test after a few weeks to see if the results are similar.

Question 7

Purpose of serum creatinine test

Answer 7

Creatinine is nitrogenous end products of metabolism filter by the kidney
examines whether creatinine is building up in your blood.
The kidneys usually completely filter creatinine from the blood.
A high level of creatinine suggests a kidney problem.

Question 8

Purpose of Blood Urea test

Answer 8

BUNare nitrogenous end products of metabolism filter by the kidney
also checks for waste products in your blood.
BUN tests measure the amount of nitrogen in the blood. Urea nitrogen is a breakdown product of protein.

Question 9

What does the Estimated GFR show?

Answer 9

estimates how well your kidneys are filtering waste per minute.

Any result lower than 60 milliliters/minute/1.73m2may be a warning sign of kidney disease.

Question 10

What causes kidney failure (4)

Answer 10

Nephrotoxins-toxic exposure to environmental pollutants or certain medications
certain acute and chronic diseases
severedehydration
kidney trauma

Question 11

What is acute renal failure?

Answer 11

abrupt deterioration in kidney function, manifested by an increase in serum creatinine level with or without reduced urine output.

Question 12

What are 3 key features of acute renal failure?

Answer 12

Increase in urea and creatinine
decreased urine output (usually but not always)
Reduced GFR

Question 13

Oliguric va anuric phase

Answer 13

Oliguric phase :Oliguria: <400 ml urine output in 24 hours

Anuria phase: Anuria: <100 ml urine output in 24 hours

Question 14

What are the four phases of Acute renal failure and the duration of each

Answer 14

1. Onset (hrs-days)
2. Oliguric (8-14 days)
3. Diuretic phase (7-14 days)
4. Recovery phase (months to years)

Question 15

What are the 3 types of ARF

Answer 15

Acute injury to kidney

Pre renal, intrinistic, post renal

Intrinistic:
Glomerular, interstitial, tubuluar and vascular

Question 16

Describe the 3 types of ARF

Answer 16

Pre renal: are those that decrease effectiveblood flow to the kidneyand cause a decrease in theglomerular filtration rate (GFR)

Intrinsic: refers to disease processes which directly damage the kidney itself. Intrinsic AKI can be due to one or more of the kidney’s structures including theglomeruli,kidney tubules, or theinterstitium.

Post renal: refers to acute kidney injury caused by disease states downstream of the kidney and most often occurs as a consequence ofurinary tractobstruction.

Question 17

Lab evaluation of acute renal failure

Answer 17

Serum creatinine (Scr),  More reliable marker of GFR
small change reflects large change in GFR

BUN, generally follows Scr increase
Elevation may be independent of GFR

BUN/Cr helpful in classifying cause of ARF
ratio> 20:1 suggests prerenal cause

Question 18

What is chronic kidney disease?

Answer 18

abnormalities of kidney structure or function that persist for more than three months.

End-stage renal disease occurs when chronic kidney disease reaches an advanced state.
In end-stage renal disease, your kidneys are no longer able to work as they should to meet your body’s needs.

Question 19

Draw a diagram to show the effects of chronic kidney disease on normal kidney functions?

Answer 19

Lecture slides

Question 20

What two criteria makes someone have Chronic Kidney disease?

Answer 20

GFR lower than 60 and Albuminuria, urine sediment abnormalities, or electrolyte and other abnormalities

Question 21

What is the order of preference of tests?

Answer 21

urine albumin-to-creatinine ratio (ACR);

urine protein-to-creatinine ratio (PCR);

reagent strip urinalysis for total protein with automated reading;

reagent strip urinalysis for total protein with manual reading.

Question 22

ARF and sepsis diagram

Answer 22

Lecture slide

Question 23

what do nephrons consist of?

Answer 23

Glomerulus and tubule

Question 24

Describe the 2 step process that nephrons use

Answer 24

the glomerulus filters your blood, and the tubule returns needed substances to your blood and removes wastes.

Question 25

Renal corpuscle contains what two structures?

Answer 25

Bowmans capsule and glomerulus