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Flashcards in Kidneys Deck (31):
1

which artery supplies the kidneys

Renal Artery

2

which vein supplies the kidneys

Renal vein

3

what is osmoregulation

homeostatic control of blood water potential

4

what are the sections of the kidneys

Capsule
Cortex
Medulla
Pelvis

5

what takes the waste product from the kidneys to the bladder

Ureter

6

what is the filtering unit of the kidney?

the Nephron

7

Name the different sections of the nephron

Glomerulus (inside the Bowman's Capsule
proximal convoluted tubule
Loop of Henle
distal convoluted tubule
collecting duct

8

how do the kidneys maintain a higher blood pressure than the rest of the body

afferent arterioles are wider then efferent

9

what processes do the kidneys do?

ultrafiltration
selective reabsorption
excretion

10

what is the function of the glomerulus

Ultrafiltration

11

describe the process of ultrafiltration?

-Blood enters the kidneys through the renal artery
-high blood pressure (caused by the afferent arterioles being wider than the efferent arterioles) forces liquid and dissolved solutes out of the blood
-tissue fluid collects in the Bowman's Capsule

12

What is the glomerulus

a network of capillaries within the Bowman's Capsule

13

what layers does the filtrate need to pass through to leave the blood and enter the Bowman's Capsule

Endothelium (single cell layer of the capillaries)
Basement membrane- (glycoprotein and collagen mesh)
Podocyte layer- foot like projections that fit together with a gap

14

where does selective reabsorption happen

in the proximal and distal convoluted tubules

15

what percentage of reabsorption happens in the PCT

80%

16

what is reabsorbed in the PCT

Na+
Cl-
glucose
amino acids
water

17

describe the process of selective reabsorption of Na+ from the lumen of the proximal convoluted tubule to the blood

-Na+ brought into the cells of the PCT down its concentration gradient through co transport with glucose and Cl- (from a high concentration in the lumen of the PCT to a low concentration of the cells of the PCT) PASSIVE

-glucose moves into the blood down its concentration gradient (facilitated diffusion- PASSIVE)

-Na+ actively transported out of cell into blood through Na+ K+ pump ACTIVE

18

how are the cells of PCT adapted for its function

large surface area- microvilli
many mitochondria- for active transport of Na+

19

why do the cells of the PCT contain many Mitochondria

ATP is needed for active transport of Na+ into the blood

20

what is the is the descending Loop of Henle permeable to

WATER
and salts (Na+ Cl-)

21

What is the function of the loop of Henle

to create an area of high solute concentration (and therefore low water potential) in the medulla

22

what is the countercurrent multiplier mechanism

mechanism by which at all points in the loop of Henle the solute concentration is higher in the ascending L of H than the Descending L of H

23

what is the ascending loop of Henle permeable to

salts Only
(in reality it is slightly permeable to water but a lot less than the descending loop)

24

descreibe how the Loop of Henle causes the reabsorption of water from the filtrate

-the ascending L of H is more permeable to salts
-ions move out of the lumen of A L of H to the medulla by diffusion lower down the ascending Loop of Henle and by active transport further up
-this lowers the water potential of the medulla
-water moves out of the descending loop of Henle down its osmotic gradient and are absorbed into the blood
-this gradient also causes water to move out of the collecting ducts

- some Na+ and Cl- ions diffuse into the Descending loop of Henle

25

which area of the brain is responsible for osmoregulation

Hypothalamus

26

which hormone acts on the collecting duct

Antidiuretic Hormone (ADH)

27

where is ADH released from

Posterior Pituitary gland

28

what does ADH do in the kidney

-acts on the collecting duct and distal convoluted tubules
-makes them more permeable to water
-makes urine more concentrated

29

describe the process of osmoregulation in a dehydrated person

-blood water potential decreases
-osmoreceptors in hypothalamus detect low water potential in the blood
-more ADH secreted by posterior pituitary gland
-DCT and CD made more permeable to water
-more water reabsorbed from collecting duct
-more concentrated urine

30

describe the process of osmoregulation in a hydrated person

-blood water potential increases
-osmoreceptors in hypothalamus detect high water potential in the blood
-less ADH secreted by posterior pituitary gland
-DCT and CD less permeable to water
-less water reabsorbed from collecting duct
-less concentrated urine

31

why would the length of L of H change between species?

species living in hot climate need to conserve more water- have a longer L of H