Kidney Function and Structure

Question 1

What is the function of the kidney?

Answer 1

• Regulation of water and electrolyte balance
• Excretion of metabolic waste
• Excrete drugs and hormones
• Regulation of arterial blood pressure
• Produce erythropoietin
• Vitamin D activation
• Gluconeogenesis (starving animal)

Question 2

What is the basic functional unit of the kidney?

Answer 2

Nephron

Question 3

What functions does the nephron have on kidney function?

Answer 3

Filtration
Reabsorption
Secretion

Question 4

What is the relationship between body weight, blood volume, and number of nephrons per kidney?

Answer 4

Number of nephrons increase as bw and bv go up

Question 5

What can cause loss of functional nephron unit?

Answer 5

Polycystic kidney disease. Can see this disease in cats and humans (especially Persians)

Question 6

What makes up the basic unit of the nephron?

Answer 6

• Renal corpuscle/ glomerulus
• Proximal tubule
• Loop of henle
• Distal tubule
• Collecting duct

Question 7

What makes up the renal corpuscle?

Answer 7

• Glomerulus - capillary tuft

- Bowmans capsule- responsible for filtration of solutes

Question 8

How are solutes discriminated for in the renal corpuscle?

Answer 8

• Size
• Change
• Shape

Question 9

Where is most of filtered solutes reabsorbed?

Answer 9

Proximal tubule

Question 10

How are solutes reabsorped in the proximal tubule?

Answer 10

• Na coupled transport- glucose, aa, HCO3

- Isotonic transport- High water and junctional permeabilities

Question 11

How much of glucose is absorbed?

Answer 11

All should be absorbed before it leaves the PT

Question 12

What are the segments of the PT?

Answer 12

• S1 much taller and lots of mitochondria and long brush border
• S2 little smaller than S2
• S3 much smaller with less mitochondria

Question 13

What are the two types of nephrons?

Answer 13

Cortical nephrons and juxtamedullary nephrons

Question 14

What is the type of nephron important in concentrating mechanism?

Answer 14

Juxtamedullary nephrons

Question 15

How do desert animals combat low water level?

Answer 15

High concentration ratios of urine to plasma

Question 16

What are the portions of the loop of Henle?

Answer 16

• Thin descending
• Thin ascending
• Thick ascending

Question 17

What are the permeabilities in the loop of Henle?

Answer 17

• TD high H2O and no NaCl
• TA High NaCl no H2O
• ThickA High active transport of NaCl no H2O

Question 18

Fluid leaving loop of Henle is what?

Answer 18

Very dilute

Question 19

How do you coordinate renal blood flow and glomerular filtration rate?

Answer 19

• Tubuloglomerular feedback

- Salt sensing and regulation by macula densa cells in the juxtaglomerular apparatus

Question 20

What cells secrete renin?

Answer 20

Granular cells

Question 21

Which parts of the nephron are hormonally regulated?

Answer 21

Distal convoluted and collecting duct

Question 22

What happens in the Distal convoluted tubule?

Answer 22

Absorption of Na, Cl, and Ca

Question 23

What is the function of the collecting duct?

Answer 23

-Fine tune salt, H2o and Acid base balance

Question 24

What increases Ca absorption in the DCT?

Answer 24

Parathyroid hormone

Question 25

What are the parts of the collecting duct?

Answer 25

- Cortical - Outer medullary - Inner medullary

Question 26

What kind of cells are found in the collecting ducts?

Answer 26

Heterogenous

Question 27

What hormones act on the collecting duct system?

Answer 27

Aldosterone- Increase Na absorption | ADH- Increase aquaporins and water absorption