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Flashcards in Urinary System Deck (130)
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1

What are the functions of the kidney?

Regulation of fluid and volume, electrolyte balance, excretion of waste, production of hormones

2

Where does filtration and collection occur in the kidneys?

Filtration- cortex
Collection- medulla

3

Order these organs from start to finish: Ureter, urethra, kidney, bladder

Kidney, ureter, bladder, urethra

4

Outline blood flow in kidneys

Renal artery, segmental arteries, interlobar arteries, arcuate arteries, interlobular arteries, afferent arteriole, glomerulus, efferent arteriole, peritubular capillaries, interlobular vein, arcuate vein, interlobar vain, renal vein

Really, Small, Indians, Aim, Inside

5

After filtration in the glomerulus describe the route of the filtrate to the collecting duct?

Proximal convoluted tubule, descending loop of henle, ascending loop of henle, distal convoluted tubule, collecting duct

6

Where does the nephron enter the medulla?

At the bottom of the loop of henle

7

What force is responsible for filtration?

The difference in hydrostatic pressure and protein-osmotic pressure

8

Why is the glomerular filtration rate high?

To remove toxic substances quickly

9

How is the GFR high?

Large SA across filtration and size difference between afferent and efferent arterioles and low resistance of thin porus membrane

10

What is tubular reabsorption?

The process of returning substances from filtrate back to renal interstitial then renal blood vessels

11

What are the mechanisms of tubular reabsorption?

active transporters, osmosis, solvent drag, co-trasporters

12

What three barriers filter the blood?

Capillary endothelium, basement membrane, podocytes

13

What does the endothelial cells filtrate?

Prevents blood cells allows components to pass

14

What does the basal lamina filter?

Prevents large proteins

15

What do podocytes prevent filtration of?

Medium sized proteins

16

What is the definition of the GFR?

Volume of fluid filtered from the glomerular capillaries into bowmans space per min

17

What is the difference between paracellular and transcellular reabsorption?

Paracellular- between cells
Transcellular- through cells

18

How does tubular reabsorption occur in the proximal tubule?

Na+ is diffuses from lumen into tubular cell is pumped into interstitial fluid and diffuses into capillaries, water follows by osmosis, causing solvent drag, this increases conc gradients of all other ions, chloride moves down electrochemical gradient, therefore K, Ca, Mg diffuse

19

How does the proximal tubule increase surface area?

Tubular luminal side has villi like structures

20

How is glucose reabsorbed in the proximal tubule?

Secondary active transport using Na, glucose symporter then diffusion into the capillaries

21

What causes glucose to reach the urine?

Filtration of glucose can saturate, reabsorption can be saturated and no where else can absorb the glucose

22

How is phosphate reabsorbed and regulated?

Reabsorbed same as glucose, regulated by parathyroid hormone

23

How does Na/H exchanger allow reabsorption of Bicarbonate?

Binds to bicarbonate producing H2O and CO2 which can pass through into the proximal tubule cells and bicarbonate is reproduced using carbonic anhydrase and diffuses into blood

24

Why is not all H+ effective for reabsorbing bicarbonate?

Some binds to HPO4 and is excreted

25

How are the small proteins returned to blood?

Endocytosis in the PCT, degradation in tubular cells to amino acids diffuses into capillaries

26

Why is a high filtration rate needed to prevent high concentration of Urea being reabsorbed?

Urea is slightly lipid soluble so can move down concentration gradient into blood therefore high rate needed to prevent more of this

27

Why does water leave the descending limb by osmosis?

The solute from the ascending limb increases ISF concentration water follows by osmosis

28

How does the osmolarity change down the medulla?

Increases

29

How does the LOH and vase recta cause a counter current?

Vassa recta runs parallel and in opposite direction of LOH

30

Why does the osmolarity of the vassa recta increase down the medulla

As it runs down the ions of ascending limb diffuse in increasing osmolarity as it runs up by descending limb water moves in by osmosis