Renal Physiology Part 2

Front 1

What is glomerular filtration rate?

Back 1

The measurement of functional capacity of the kidney

Controls the amount of reabsorption

Front 2

What is GFR dependent on?

Back 2

It is dependent on difference in pressure between capillaries and Bowman's space

Front 3

What drives glomerular filtration rate?

Back 3

Net filtration pressure

Front 4

What does high pressure do to GFR?

Back 4

Increases filtration rate

Front 5

What is the goal of glomerular filtration?

Back 5

To regulate GFR

Front 6

What happens when GFR is too high?

Back 6

Needed substances cannot be reabsorbed quickly enough and are lost in urine

Front 7

What happens when GFR is too low?

Back 7

Everything is reabsorbed, including wastes that are normally disposed of

Front 8

What is the relationship between GFR and MAP?

Back 8

GFR and MAP are directly proportional

Front 9

What are the 3 modes of GFR regulation?

Back 9

Myogenic response

Tubuloglomerular feedack

Hormonal regulation

Front 10

What is a myogenic response?

Back 10

It is similar to autoregulation in other systemic arterioles

Front 11

What is involved in tubuloglomerular feedback?

Back 11

Na+, K+, Cl-

Front 12

What are hormones and autonomic neurons regulated?

Back 12

By changing resistance to arterioles

By altering the filtration coefficient

Front 13

What triggers a myogenic response?

Back 13

Myogenic response is triggered by an increase or decrease in blood pressure

Front 14

What happens to GFR if BP is increased?

Back 14

GFR increases

Front 15

What happens to blood vessels if GFR is too high?

Back 15

Blood vessels constrict

Front 16

What happens during vasoconstriction?

Back 16

There is a decrease in diameter in the afferent arteriole, which causes blood flow to decrease and volume in the glomerulus to decrease

Front 17

What happens to GFR if BP decreases?

Back 17

GFR decreases

Front 18

What happens to reabsorption when GFR decreases?

Back 18

Reabsorption increases

Front 19

What causes GFR to increase?

Back 19

Vasodilation of the afferent arteriole

Front 20

What is involved in the tubuloglomerular mechanism?

Back 20

Macula densa cells in the DCT

Front 21

What are Macula Densa cells?

Back 21

They are cells that are sensitive to Na+

Front 22

What does it mean if Na+ is high in DCT?

Back 22

GFR is too high and not enough Na+ is being absorbed in the kidney tubule

Front 23

How do you decrease GFR?

Back 23

Constrict the afferent arteriole

Front 24

What does constriction of the afferent arteriole have to do with filtration and reabsorption?

Back 24

Filtration decreases

Reabsorption increases

Front 25

If Na+ in the DCT is too low, what is the GFR?

Back 25

GFR is low

Front 26

What happens to reabsorption when GFR is low?

Back 26

Reabsorption increases

Front 27

How do you increase reabsorption?

Back 27

The afferent arteriole vasodilate and increases blood flow to the glomerulus

Front 28

What are potent constricters of blood vessels?

Back 28

NorEpi and Epi

Front 29

What part of the adrenal gland releases NorEpi?

Back 29

The adrenal medulla

Front 30

What happens to blood flow when you vasoconstrict?

Back 30

Blood flow decreases

Front 31

What happens to GFR and GHP when blood flow decreases?

Back 31

GFR decreases and GHP decreases

Front 32

What happens to reabsorption when GFR decreases?

Back 32

Reabsorption increases

Front 33

What does angiotestin II do to the afferent arteriole?

Back 33

Causes afferent arteriole to vasoconstrict

Front 34

When is Renin released from the juxtoglomerular apparatus?

Back 34

Aff. art. MAP drops

Macula densa cells sense low plasma osmolarity or low Na+

Front 35

What does the kidney secrete when BP decreases?

Back 35

Kidney secretes renin from the juxtoglomerular apparatus

Front 36

What does renin convert?

Back 36

Renin converts angiotensinogen to angiotensin I

Front 37

What is angiotensin I converted to?

Back 37

Angiotensin I is converted to angiotensin II by the angiotensin converting enzyme (ACE)

Front 38

What is one effect of angiotensin II?

Back 38

The thirst reflex

If you have a decrease in BP, the fastest way to increase blood volume is to drink H2O

Front 39

What is another effect of angiotensin II?

Back 39

Vasoconstriction

Front 40

What happens when angiotestin II goes back into the adrenal gland?

Back 40

It stimulates the hormone aldosterone

Front 41

Where does aldosterone go?

Back 41

Aldosterone goes back into the kidney

Front 42

What does aldosterone do?

Back 42

Aldosterone increases the absorption of Na+

Front 43

If you lost a lot of blood from hemorrhaging, why would you increase Na+ absorption?

Back 43

It increases water reabsorption in the kidney. Therefore it increases blood volume

Front 44

Why is aldosterone secreted?

Back 44

To control blood volume

Front 45

Where is ADH released from?

Back 45

The neurohypophysis

Front 46

What is the function of ADH?

Back 46

It controls blood osmolarity

Front 47

What triggers the Renin-Angiotestin-Aldosterone System?

Back 47

Triggered by low pressure due to low blood volume or low Na+ concentrations

Front 48

How does aldosterone increase blood volume?

Back 48

By increasing Na+ absorption from the DCT and the collecting ducts of the kidney

Front 49

What is the creatinine clearance rate?

Back 49

Volume of blood plasma that is cleared of creatinine/ time

Front 50

What does it mean if there is a high amount of creatinine in the urine?

Back 50

GFR is high

Front 51

What does low creatinine amount in urine say about GFR?

Back 51

GFR is low

Front 52

What does the PCT reabsorb?

Back 52

Na+ and glucose

Front 53

What does glucose absorption depend on?

Back 53

The absorption of Na+

Front 54

What does Na+ and H2O regulate?

Back 54

ECF volume and osmolarity

Front 55

What does K+ regulate?

Back 55

Cardiac and muscle function

Front 56

What does Ca2+ regulate?

Back 56

Exocytosis, muscle contractions, and other functions

Front 57

What does H+ and HCO3- regulate?

Back 57

pH balance

Front 58

How does the body maintain mass balance?

Back 58

Excretion routes: kidney and lungs

Front 59

How is Na+ reabsorbed in the PCT?

Back 59

Active transport

Front 60

Where is glucose filtered?

Back 60

At the glomerulus

Front 61

How much glucose is actively reabsorbed in the PCT?

Back 61

100%, because normalment, no urine appears in the urine

Front 62

What happens to plasma concentration of glucose as rate of glucose movement increases?

Back 62

Plasma concentration of glucose increases

Front 63

What happens to filtration when GHP increases?

Back 63

Filtration increases

Front 64

Filtration and reabsorption match until...

Back 64

Glucose reaches transport maximum

Front 65

What happens when glucose reaches transport maximum?

Back 65

Reabsorption stalls and excretion increases

Front 66

What cells in the late distal tubule and collecting duct regulate balance?

Back 66

Principle cells and intercalated cells

Front 67

What are principal cells?

Back 67

They reabsorb Na+ based on concentrations of aldosterone

Front 68

What is on the tubular lumen side of principle cells?

Back 68

Leak channels

Front 69

What is Na+ reabsorption linked with?

Back 69

Na+ reabsorption is linked with Cl- reabsorption and K+ excretion

Front 70

What drives reabsorption?

Back 70

Concentration gradients

Front 71

What are the concentration gradients in a principle cell?

Back 71

Tubular lumen side = high concentration

In the cell = low concentration

Front 72

How does aldosterone affect Na+ reabsorption?

Back 72

It increases Na+ reabsorption

Front 73

Because aldosterone is a steroid hormone, what does it bind to?

Back 73

It binds to a receptor and enters the cell binding with the nucleus and alters the DNA

Front 74

Where is aldosterone secreted?

Back 74

In the adrenal cortex

Front 75

How does aldosterone act on principal cells of distal tubules and collecting ducts?

Back 75

It increases # of Na+/K+ pumps on basolateral membrane

It increases # of open Na+ and K+ channels on apical membrane

Front 76

What is the first site of osmotic shift?

Back 76

The loop of henle

Front 77

What occurs in the descending limb in the loop of henle?

Back 77

Water reabsorption in the descending limb

Front 78

What happens to osmolarity in the kidneys if water reabsorption occurs?

Back 78

Osmolarity in the kidneys increase

300 mOsm to 1200 mOsm

Front 79

What is reabsorbed in the ascending limb?

Back 79

Na+, K+, and Cl-

Front 80

How does the reabsorption of ions affect the osmolarity?

Back 80

It decreases osmolarity

1200 mOsm to 100 mOsm

Front 81

What is the difference between the limbs of the loop of henle?

Back 81

300 mOsm - 100 mOsm = 200 mOsm

Front 82

What drives reabsorption in the descending limb?

Back 82

The reabsorption of salt at the ascending limb

Salt moves from filtrate to ISF (bathes the descending loop of henle)

Front 83

What is a diuretic?

Back 83

It increases urine output

Front 84

What happens to H2O reabsorption in the descending limb if you decrease the reabsorption of Na+, K+, and Cl- in the ascending loop of henle?

Back 84

H2O reabsorption will decrease in the descending limb

Front 85

What happens to urine volume if H2O reabsorption in the ascending loop decreases?

Back 85

Urine volume increases

Front 86

What happens to urine osmolarity when there is a decrease in the reabsorption of Na+ in the ascending limb?

Back 86

Urine osmolarity increases because urine is retaining more salt than water

Front 87

What is the normal pH of arterial blood?

Back 87

7.35-7.45

Front 88

What does a pH < 7.35 indicate?

Back 88

Acidosis

Front 89

What does a pH > 7.45 indicate?

Back 89

Alkadosis

Front 90

What are some complications with acid-base disturbance?

Back 90

Conformation change in protein structure

Changes in excitability of neurons

Changes in K+ balance

Cardiac arrhythmias

Vasodilation

Front 91

What is bicarbonate reabsorption coupled with in the PCT?

Back 91

Hydrogen secretion

Front 92

In the DCT, what is synthesized as H+ is secreted?

Back 92

Bicarbonate