function of the nephron

Question 1

where does ulterfiltration occour

Answer 1

the glomerulas

Question 2

what is the artriole that takes blood into the glomerulas called

Answer 2

the efferent artriole

Question 3

what is the glomerulas comprised of

Answer 3

capillaries

Question 4

what are the glomerular capillaries made up of

Answer 4

epithelial cells with pores between them

Question 5

what is formed in the glomerulas that allows ulterfiltration to occour

Answer 5

hydrostatic pressure is formed

Question 6

how is this hydrostatic presure formed

Answer 6

the differance in size between the afferent artriole wich has a smaller diameter compared to the efferent atriole.

Question 7

what does this hydrostatic pressure do

Answer 7

forces small water glucose and mineral ions into bomans capsual forming glomerular filtrate

Question 8

what is the water, glucose and mineral ions known as when pushed out of pores

Answer 8

glomerular filtrate

Question 9

what remains in the blood stream

Answer 9

blood cells and protiens

Question 10

why do they reamain in the blood stream

Answer 10

they are too large

Question 11

what do these large cells leave via

Answer 11

the efferent atriole

Question 12

what occours after uterfiltration

Answer 12

selective reabsorbtion

Question 13

where does selective reabsorbtion happen

Answer 13

the proximal convoluted tubual

Question 14

what absorbs glucose and aa into the blood

Answer 14

epithelial cells in the lining of the pct

Question 15

what makes the epithelial cells suited for their absorbtion

Answer 15

microvilli - provide large SA
mitochondria - provide lots of energy for active transport and co transport

Question 16

what is the mitochondria in the epithelia cells used for

Answer 16

active and co - transport

Question 17

describe the process of reabsorbtion

Answer 17

sodium ions actively transported into the blood lowering the sodium con in epithelial cells.
sodium ions diffuse down con-gradient into cells via facilitated diffusion with the use of a carrier protein.
travels from lumen of pct into epithelial cells surrounding it.
carrier protiens contransport molcules such as glucose and aa into epithelial cells
co-transported molecules diffuse dwn a conc gradient into the blood.

Question 18

how do glucose molecules move into epethillial cells

Answer 18

via co-traqnsport with sodium ions through a carrier protien

Question 19

how do sodium ions move into the epithellial cell

Answer 19

facillitated diffusion

Question 20

how are the co-transported molecules transported into the blood stream

Answer 20

via diffusion down a conc gradient wich is alwas maintained as blood constantly moves away

Question 21

how is ultra filtration resisted out of the glomerulas

Answer 21

cappillary epithelial cells
epithelila cells of renal capsual

Question 22

what is esential for selective reabsorbtion in terms of establishing conditions

Answer 22

maintaining the gradient of sodium ions

Question 23

what miantains the gradient of sodium ions

Answer 23

loop of henle

Question 24

what are the two regions in the loop of henle

Answer 24

descending limb
ascending limb

Question 25

what is the differance between the ascending and descending loop

Answer 25

descending lopp is permiable to water ascending loop has thicker walls so is not

Question 26

why is the ascending loop imperable to water

Answer 26

because it has thicker walls

Question 27

what happens in the ascending loop of henely

Answer 27

sodium ions actively transported out into intertitial space

Question 28

what does the active transport of na ions out of ascending loop mena

Answer 28

lowers water potential outside

Question 29

due to the low water potential outside loop of henle what happens

Answer 29

water moves out of descending loop into the surrounding blood capillaries wich is hopw water enters the blood

Question 30

where else does water go when it moves out os descending limb

Answer 30

interstitial space

Question 31

what is the concentration at the bottom of the loop of henle

Answer 31

high conc of na+ ions becuase most water has moved out via desceding loop, this means that na+ ions can easily diffuse out into interstitial space

Question 32

why is their a high conc of na ions at the bottom of loop of henle

Answer 32

because most water has moved out via descending loop

Question 33

what does this high conc of sodium ions mean

Answer 33

sodium can easily diffuses out into interstitial space

Question 34

what changes that makes na+ ions move out of ascending loop via activetransport

Answer 34

as their is a large amount of na+ ions at the bottom of the loop of henle they can easliy move out via diffusion but as more move out the conc of na+ ions left is lower so they have to move out via active transport

Question 35

what does the movment of the na+ ions out of the ascending loop result in

Answer 35

a filtrate with a high water potential

Question 36

why does it result in a filtrate with a high water potential

Answer 36

as water is unable to move out in the ascending loop due to it's thick walls

Question 37

after movement out of loop of henle where does filtrate go

Answer 37

collecting duct

Question 38

what happens at the collecting duct

Answer 38

water moves out via osmosis into blood capillaries

Question 39

what does the osmosis of water out of collecting duct mean

Answer 39

lowered water potential

Question 40

what continues to allow osmosis in collecting duct even when their is a low water potential in collecting duct

Answer 40

water potential of filtrate is lower but so is water potential of interstilita space due to the constant movement of blood taking water away so water keeps moving out of collecting duct. this is an example of the counter current model

Question 41

why is the water potential of interstial space still lower than that in collecting duct

Answer 41

due to constant movement of water away bu the blood capillaries