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Flashcards in Microscopic anatomy of the urinary tract Deck (46)
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1

Describe the vascularisation of the kidney

- Supplied by single branch of aorta (renal artery)
- Splits into interlobar artery within kidney
- Then arcuate artery
- Then interlobar artery
- Into vasa recta
- Into arcuate vein, then interlobar vein and then renal vein out into caudal vena cava

2

What is the reason for the gross appearance of cat kidneys?

The subscapular veins run towards the hilum of the kidney, givign a grooved appearance

3

What is meant by end arteries?

- Vessels that do not have anastomoses with a back up blood supply
- Closed blood supply

4

What is the relevance of end arteries to renal function?

- Renal arteries are end arteries
- Damage to an artery will lead to a whole section losing its blood supply and dying off

5

What is the nephron?

The functional unit of the kidney

6

What is the nephron made up of?

- The renal corpuscle (glomerulus)
- And the tubular system

7

What are the components of the tubular system of the nephron? (in order)

- Proximal convoluted tubule
- Loop of Henle
- Distal convoluted tubule
- Collecting duct (drains into pelvis)

8

What components are found in the renal cortex

- Proximal and distal convoluted tubues
- Glomeruli

9

What components are found in both the inner and outer medulla of the kidney?

- The thin loops of Henle
- Collecting ducts

10

What is found in the outer medulla?

- Straight proximal tubule (S3)
- Thick ascending loop
- Collecting ducts
- Thin tubules
- Vasa recta

11

What is found in the inner medulla?

- Collecting ducts
- Thin tubules
- Vasa recta

12

What can be seen in the cortex of the kidney on histology?

- Renal corpuscles
- Convoluted tubules
- Medullary rays

13

Describe the glomerulus

- Aka renal corpuscle
- Vascular tuft/ capillary bundle
- Fneestrated so filtrate drains out
- Pressure difference between afferent and effect arteriole to facilitate filtration

14

Which has higher pressure, the afferent or the efferent arteriole in the kidney?

- The efferent
- Facilitates filtration through the glomerulus

15

Describe Bowman's capsule

- Inner (visceral) layer made up of podocytes
- Outer (parietal) layer
- Not directly in contact with blood
- Podocytes between vascular tuft and inner of capsule

16

What are the filtration mechanisms found in the glomerulus?

- Physical
- Electrical

17

What is the function of the podocytes in Bowman's capsule?

- Filter to keep proteins in the blood

18

What are the mesangial cells?

- Mesothelium of the capillary tuft (glomerulus)

19

What are the functions of the mesangial cells?

- Properties of immune and smooth muscle cells
- Assist filtration barrier
- Provide structural support
- Phagocytose foreign material

20

List the filtration apparatus of the glomerulus

- Fenestrated capillary endothelium
- Charge of the glomerular basement membrane (-ve charge, repels anions)
- Podocytes
- Physical action of glomerular basement membrane

21

How do podocytes act to filter the blood?

- Have primary and secondary processes
- Pedicels
- Filtration slite between pedicels
- Anything larger than slit will not pass through

22

Describe the structure of the proximal tubule

- Made up of 3 segments
- S1, S2, S3
- S1,2 are convoluted, S3 is straight
- Brush border
- Basal striation
- Interdigitation of basal processes
- Infolding of basal cell membrane to increase SA

23

What is the function of the proximal tubule?

- Majority of transport
- Bulk absorption
- Reabsorption from filtrate e.g. glucose

24

How does the proximal tubule carry out its function?

- Enzymatic system
- Abundant Na/K ATPase

25

Why are there many mitochondria present in the proximal tubule cells?

- Reabsorption is an enzymatic process
- Active process, lots of ATP needed
- Mitochondria supply this ATP

26

What is the disadvantage of the enzymatic system in the proximal tubule?

- Can be overloaded
- osmotically active substances can get into the loop of Henle
- E.g. glucose

27

What are the different segments of the Loop of Henle? (in order)

- Thick descending limb
- Thin segment
- Thick ascending limb

28

What is the function of the loop of Henle?

- Concentration of urine

29

How does the Loop of Henle carry out its function?

- Countercurrent multiplier
- Water out of descending loop, ions out of the ascending loop

30

Describe the concentration of ions in the loop of Henle

- Increasing ion concentration down the loop, decreasing up the loop
- 2 isotonic regions
- Highest concentration of salts at the bottom of the loop