F214:02:04 The Kidney Flashcards Preview

F214:02 Excretion > F214:02:04 The Kidney > Flashcards

Flashcards in F214:02:04 The Kidney Deck (34):
1

Where are the kidneys positioned?

each side of the spine, just below the lowest rib

2

From which vessels does the blood enter and leave the kidneys

From the renal artery and is drained by the renal vein

3

What is the role of the kidneys?

to remove waste products from the blood and produce urine.

4

Where does urine go once it has left the kidneys?

Down the ureter to the bladder where it is stored until it is ready to be releasedaaa

5

What can you see when you take a longitudinal section of the kidney?

- an outer region (cortex)
- an inner region (medulla)
- Central pelvis
Surrounded by a tough capsule

6

Where does the pelvis lead to?

the ureter

7

What does the bulk of the kidneys consist of?

tiny tubules called nephrons

8

How many nephrons are there in a kidney?

around 1 million

9

What are nephrons closesly associated with?

tiny blood capillaries

10

Where does each nephron start?

In the cortex

11

What is a nephron?

a functional unit of the Kidney
It is a microscopic tubule that receives fluid from the blood capillaries in the cortex and converts this to urine, which drains into the ureter

12

What is the glomerulus?

a fine network of capillaries that increases the local blood pressure to squeeze fluid out of the blood.
It is surrounded by a cup / funnel shaped capsule which collects the fluid and leads into the nephron

13

Where is the glomerulus found?

In the cortex

14

What is the Bowmans capsule?

The cup shaped structure surrounding the glomerulus

15

What is ultrafiltration?

The process by which fluid from the blood is pushed into the Bowmans capsule

16

What are the four parts of the nephron which the capsule leads into?

- proximal convoluted tube
- distal convoluted tube
- loop of Henle
- collectinf duct

17

What happens as the fluid moves along the nephron?

Its composition is altered due to seletive absorption

18

What is the proximal tubule?

The part of the nephron closest to the glomerulus

19

What is the distal tubule?

The part of the neurone furthest from the glomerulus

20

What is the convoluted tube?

The part of the nephron that is bent and coiled

21

What happens to the substances in the nephron as it passes through the convoluted tube?

The useful substances are reabsorbed back into the tissue fluid and blood capillaries surrounding the nephron tubule.

22

What is the final product in the collecting duct, after the fluid has passed through the nephron?

Urine

23

How does urine leave the kidneys?

It is the final product left in the distal convoluted tube, which then passes to the collection duct, which passes down into the pelvis and down the ureter to the bladder

24

What is the afferent arteriole?

The arteriole leading blood to the glomerulus

25

What is the efferent arteriole?

The arteriole leading away from the glomerulus

26

How does the composition of fluid change in the proximal convoluted tube?

sugars, most salts and some water are reabsorbed
85% of fluid is reabsorbed

27

How does the composition of fluid change in the descending limb of the loop of Henle? (in terms of water potential)

The water potential of the fluid is decreased by the addition of salts and the removal of water

28

How does the composition of fluid change in the ascending limb of the loop of Henle? (in terms of water potential)

Water potential is increased as salts are removed by active transport

29

How does the composition of the fluid change in the collecting duct? (in terms of water potential)

Decreases by the removal of water

30

Why is water removed to lower the water potential in the collecting duct?

To ensure that urine has a low water potential, and to ensure that urine has a higher concentration of solutes than is found in the blood and tissue fluid

31

What is selective reabsorption?

Where useful substances are reabsorbed from the nephron into the blood stream which other excretory substances remain in the nephron

32

Suggest why the nephrons are convoluted

To increase the length for greater SA for absorption

33

Why are there many capillaries round each nephron?

So that materials reabsorbed from the fluid in the tubule can re-enter the blood

34

Explain why reabsorption from the nephron must be selective

Some of the molecules in the nephron are waste and must be left in the fluid to be excreted
Other molecules are useful to the body and must be reabsorbed