Anatomic Overview of the Kidneys

Question 1

Name the 4 parts of the kidney

Answer 1

1. Glomeruli
2. Tubules
3. Interstitium
4. Vascular

Question 2

Production of urine “equation”

Answer 2

Urine=Filtration + Secretion (add what you dont want) - Reabsorption (subtract what you do want to keep)

Question 3

1. Where is filtrate produced?
2. Fine tuning of substances?
3. Add & subtract large volumes of substances?
4. Reabsorb (conserve) water

Answer 3

1. Glomerulus
2. Distal convoluted tubule
3. Proximal convoluted tubule
4. Loop of Henle

Question 4

Location of right kidney

& Left.

Answer 4

Retroperitoneal, R. is cranial
Dog: R is attached, ~T12-L1/ L is slightly caudal
Cat: Pendulous, R L1-4/ L2-5

Question 5

Describe path urine flows from nephrons

Answer 5

Nephrons–> collecting ducts –> pelvis (extension of proximal ureter) –> proximal ureter
Pelvis/ureter lined by transitional epithelium/sm. muscle

Question 6

What are the greatest, moderate, and least perfused areas of kidney?

Answer 6

Renal cortex> Outer medulla > Inner medulla

Question 7

List the renal vessel blood vessel sequence.

Answer 7

Renal artery–> dorsal & ventral rami –>interlobar arteries –> arcuate a. (corticomedullary jxn) –> interlobular a. –> afferent arterioles –> glomerular capillaries –> efferent arteriole –> peritubular capillaries –> vasa recta –> venous return back to renal v.

Question 8

Why do the kidneys receive such a large proportion of the CO ?
A. B/c the kidney have an unusally high demand for O2
B. B/c it permits kidneys to produce a large quantity of glomerular filtrate
C. So that the kidneys can monitor adequacy of the RBC mass.
D. All of the above

Answer 8

Answer B. B/c it permits the kidneys to produce a large quantity of glomerular filtrate

Question 9

How does changing the resistance of the pre- and post- capillary bed sphincters separately affect kidney fxn?

Answer 9

?

Question 10

How does pressure and flow in the glomerulus affect the peritubular capillaries?

Answer 10

?

Question 11

What is unique to the cortex?

Answer 11

Has glomeruli

Question 12

What comprises the “inner stripe” of the outer medulla?

Answer 12

Thick descending tubule & thin ascending.

Question 13

What comprises the inner medulla?

Answer 13

All thin Loop of Henle

Question 14

3 cell types in the Glomerulus: (layers that contribute to separation of blood/plasma from glomerular filtrate)

Answer 14

1. Endothelial cells
2. Mesangial cells (fxn like muscle cells, phagocytic fxn)
3. Visceral epithelial cells (Podocytes)

Question 15

What are the four layers filtrate must pass through to move from blood to the Bowmans space.

Answer 15

1. Endothelial slime layer
2. Endothelium
3. Glomerular Basement Memb.
4. Podocytes. (Epithelial cells)

Question 16

What are the principle sites of ultrafiltration?

Answer 16

1. the GBM

2. Slit processes of the podocytes

Question 17

What is reabsorbed at the proximal tubule?

Answer 17

• 70% of the filtered volume

- all AA, glucose and HCO3 and filtered protein, -phosphate (under PTH control)

Question 18

What substances is the distal tubule responsible for fine tuning?

Answer 18

Fine control of:

• Na (aldosterone)
• K (aldosterone)
• Ca (PTH)
• H (aldosterone)

Question 19

What does ADH control in the collecting duct?

Answer 19

ADH controls:

• Water permeability
• Urea permeability
• Water is reabsorbed b/c of hyperosmotic gradient

Question 20

Describe the apical border of the Proximal Convoluted tubules.

Answer 20

Apical intercellular tight jxns

brush border

Question 21

Describe the basal border of the PCT

Answer 21

Intercellular interdigitations, prominent mitochondria

Question 22

Where is the Macula Densa located? Its fxn?

Answer 22

Located in the distal tubule adjacent to the Afferent Arteriole and Efferent Arteriole (vascular pole)
It detects the conc. of NaCl

Question 23

Where is the Juxtaglomerular apparatus?

Answer 23

Formed by the distal convoluted tubule and the afferent arteriole- it regulates blood pressure and filtration rate of glomerulus

Question 24

What do juxtaglomerular cells secrete? What effect does it have?

Answer 24

Renin- secreted when pressure is low, it inc. BP via RAAS

Question 25

Name the two cell types in the collecting ducts.

Answer 25

1. Principle

2. Intercalated (stain darker)

Question 26

What structures generate the medullary conc. gradient?

Answer 26

Loop of Henle and vasa recta.

Question 27

What is reabsorbed in the Descending Loop of Henle? Ascending Loop?

Answer 27

Descending= water reabsorption
Ascending = salt (b/c impermeable to water)
passive thin loops
active thin loops