Ch 25 Urinary Part 2

Question 1

What are the 2 classes of nephrons?

Answer 1

Cortical and Juxtamedullary

Question 2

Where are the cortical nephrons located?

Answer 2

entirely in cortex and are more numerous

Question 3

Why are juxtamedullary nephrons important? What do they do?

Answer 3

important in the production of the urine

Question 4

What consists of the juxtamedullary nephrons?

Answer 4

• long nephron loops deeply invaded in the medulla

- thick and thin acesending limbs

Question 5

What do the mansa dansa cells do?

Answer 5

they act as chemoreceptors that monitor NaCl concentration of filtrate entering DCT

Question 6

What do the Granular cells do?

Answer 6

smooth muscles cells that secrete renin. They act as mechanoreceptors that sense blood pressure in the afferent arteriole.

Question 7

What does the extraglomerular do? (mesengial)

Answer 7

passes signals between mansa densa cells and granular cells

Question 8

What does the afferent arteriole supply?

Answer 8

The glomerulus

Question 9

What drains the glomerulus?

Answer 9

the efferent arteriole

Question 10

What does the glomerular filtration do?

Answer 10

produces cells and protein free filtrate

Question 11

What does tubular reabsorption do?

Answer 11

moves substances from filtrate back to blood (glucose)

Question 12

What does tubular secretion do?

Answer 12

moves substances from blood that couldn’t pass through the filtration membrane into the filtrate

Question 13

Urine is produced from _____

Answer 13

Filtrate

Question 14

Filtrate is produced via ____

Answer 14

glomerular filtration

Question 15

The percent of blood plasma entering glomeruli that becomes glomerular filtrate

Answer 15

filtration fraction (16-20 % is normal)

Question 16

In the filtration membrane blood comes in the

Answer 16

larger afferent arteriole

Question 17

What happens when the filtration membrane is constricted?

Answer 17

its shunts and cuts of blood meaning less fluid

Question 18

What does the glomerular capsule space do in the membrane filtration?

Answer 18

caputures filtrate that escapes from glomerulus

Question 19

What are the 3 layers of the filtration membrane

Answer 19

capillary endothelium
basement membrane
foot processes of podocyte of glomerular capsule

Question 20

What does the capillary endothelium do?

Answer 20

contains fenestrations that blocks blood cells

Question 21

What doe the basement membrane do?

Answer 21

it blocks all the smallest proteins

Question 22

What do the foot processes of podocytes do?

Answer 22

they are little spaces with with filtration slits and slit diaphragm that block macromolecules (large proteins, polysaccharides)

Question 23

What is filtration (in membrane) ?

Answer 23

flow of liquid through a membrane due to hydrostatic pressure (pressure inside capillaries that pushes through filtration membrane)

Question 24

Who holds greater volume of fluid? Capillaries of filtration membrane of glomeruli?

Answer 24

filtration membrane of glomeruli

Question 25

What molecules does the filtration membrane allow to pass?

Answer 25

has to be smaller than 3nm | water, glucose, amino acids, nitrogenous wastes

Question 26

Why are plasma proteins remained in the blood?

Answer 26

to maintain colloid osmotic pressure prevents water loss of capsular space proteins in filtrate indicate membrane problem

Question 27

Hydrostatic pressure in glomerular capillaries

Answer 27

glomerular blood pressure | 55 mm HG

Question 28

What does the hydrostatic pressure in the glomerular capillaries do?

Answer 28

forces fluid out of glomerulus into glomerular capsule space

Question 29

Hydrostatic pressure in capsular space

Answer 29

filtrate pressure in capsule | 15 mm Hg

Question 30

What does the hydrostatic pressure do in capsular space?

Answer 30

pushes back into glomerulus

Question 31

colloid osmotic pressure in capillaries

Answer 31

pull of proteins in blood 30 mmHg

Question 32

What is the net filtration pressure?

Answer 32

sum of forces

Question 33

If pressure was higher than normal, would the NFP go up or down?

Answer 33

Up to produce more urine

Question 34

What is the glomerular filtration rate?

Answer 34

vol of filtrate formed per min by kidneys

Question 35

What is the GFR ( glomerular filtration rate) proportional to?

Answer 35

Net filtration pressure total surface area available for filtration filtration membrane permeability

Question 36

What does tubular reapsorption do?

Answer 36

quickly reclaims most of the tubular contents (filtrate) and returns them to blood

Question 37

Where does tubular reasporbtion occur?

Answer 37

In renal tubules

Question 38

What is Tubular secretion?

Answer 38

reabsorption in reverse | forces things from blood INTO filtrate

Question 39

What does tubular secretion occur?

Answer 39

in the PCT to contron blood ph

Question 40

What is the transcellular route for tubular reabsorption?

Answer 40

1. transport across the apical membrane 2. diffusion across the cytosol 3. Transport across the basolateral membrane 4. movement through the interstitial fluid and into capillary

Question 41

Paracellular route for tubular reabsorption

Answer 41

1. movement through leaky tight junctions particularly in PCT 2. movement through the interstitial fluid into capillary

Question 42

What happens during the tubular reabsorption of Na?

Answer 42

allows water and other solutes to be reabsorbed

Question 43

What is sodium potassium pump? (Location, Function)

Answer 43

located in the basolateral membrane pumps Na into intersitial space uses 6% daily ATP (active transport process)

Question 44

Na K pump establishes concentration gradient for..

Answer 44

secondary active transport

Question 45

Organic nutrients that reabsorbed by secondary active transport and are cotransported with Na +

Answer 45

glucose, amino acids, some ions and vitamins

Question 46

Tubular reabosrption of water/nutrients via active/passive transport steps

Answer 46

1. at Basolateral membrane Na+ is pumped via Na K pump. Active transport creates concentration gradients that drive... 2. Downhill Na+ entry at the apical membrane 3. Reabsporion

Question 47

Tubular reabosrption of water/nutrients via active/passive transport steps

Answer 47

1. at Basolateral membrane Na+ is pumped via Na K pump. Active transport creates concentration gradients that drive... 2. Downhill Na+ entry at the apical membrane 3. Reabsporion of organic nutrients and ions by contransport at apical membrane 4. Reabsorption of water by omosis via aquaporins. water reabosorption increases the concentration of solutes that are left behind. these solutes can then be reabsorped as the move down gradients 5. lipid soluble substances diffused by transcellular route 6. Various ions (Cl Ca K) and urea diffuse by paracellular route

Question 48

When carriers for a solute is saturated, excess is exerted into ___.

Answer 48

urine

Question 49

Transport maximum

Answer 49

exists for every reabosrbed susbtance and reflects the number of carriers in renal tubules that are available

Question 50

What is hyperglycemia and what does it lead to regarding transport maximum

Answer 50

leads to high blood glucose levels that exceed Tm , and glucose spills over into urine

Question 51

Filtrate volume that is reabosorbed in PCT

Answer 51

65 % of filtrate vol is reabsorbed H20, Na+ and HCO3- Glucose, amino acids, and other nurtrients

Question 52

What does the PCT secrete?

Answer 52

H+ and NH4+ and some drugs

Question 53

The descending limb absorbs...

Answer 53

water

Question 54

What does the DCT absorb?

Answer 54

Na+ (aldestrone) and Ca+ (parathyroid)

Question 55

What does the DCT secrete?

Answer 55

K+ by aldostrone

Question 56

What does the ascending limb absorb?

Answer 56

Na+ K+ Cl-

Question 57

What does the ascending limb secrete?

Answer 57

urea

Question 58

What does the collecting duct absorb?

Answer 58

H20 (by ADH) Na+ (by Aldosterone) Cl- follows Urea (increased by ADH)

Question 59

What does the collecting duct secrete?

Answer 59

K+ by aldosterone