Unit 5 Lecture 34 Flashcards Preview

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Flashcards in Unit 5 Lecture 34 Deck (57)
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1
Q

Function of the renal corpuscle

A

Filtration

2
Q

What is filtered in the renal corpuscle?

A

Water and blood solutes (except proteins) like ions, glucose, amino acids, creatinine, urea, and uric acid

3
Q

Compare the concentration of blood to fluid in the glomerular’s capsule

A

isotonic = equal to

4
Q

What is the mOsm/liter of fluid in the renal capsule?

A

300 mOsm/liter

5
Q

What part of the nephron does most of the reabsorption?

A

PCT

6
Q

By what process does water follow solutes?

A

osmosis

7
Q

By what process doe small proteins move across into the blood?

A

pinocytosis

8
Q

What is tubular secretion?

A

Materials move from blood to tubular fluid

9
Q

Purpose of secretion

A
  • controls blood pH through secretion of H+

- eliminates certain substances (NH4+, creatinine, K+)

10
Q

What are the 2 different types of reabsorption?

A
  1. Paracellular reabsorption

2. Transcellular Reabsorption

11
Q

What happens during paracellular reabsorption?

A

50% of reabsorbed material moves between cells by DIFFUSION in some parts of tubule

12
Q

How do materials move between cells in paracellular reabsoprtion?

A

Diffusion

13
Q

What happens during transcellular reabsorption?

A

material move through both APICAL and BASAL membranes of tubule cell by ACTIVE TRANSPORT

14
Q

How do materials move between cells in transcellular reabsoprtion?

A

Active transport

15
Q

Define active transport

A

transportation that requires energy (ATP) to move particles

16
Q

What are two major things needing to be reabsorbed?

A

Na+ and water

17
Q

How is Na+ reabsorbed?

A

Na+/K+ ATPase pumps on the basolateral membrane pumps Na+ from tube into ISF

18
Q

What process reabsorbed water?

A

osmosis

19
Q

What are the 2 types of osmosis reabsorption of water?

A
  1. Obligatory water reabsorption

2. facultative water reabsorption

20
Q

Define obligatory water reabsorption

A

Water is “obliged” to follow the solutes being reabsorbed

21
Q

Define facultative water reabsorption

A

@ collecting duct under the control of ADH

22
Q

What does ADH do to the collecting duct?

A

ADH inserts aquaporins into the basolateral membrane that allows the reabsorption of water

23
Q

What is the function of the PCT?

A

reabsorption and secretion

24
Q

Where does the majority of nephron reabsorption occur and why?

A

PCT - microvilli on cells increase surface area and increase reabsorption

25
Q

What filtrates are reabsorbed into blood at the PCT?

A

water, Na+, K+, glucose, amino acids

26
Q

What structure is found on the apical membrane that helps reabsorb more materials from tubular filtrate

A

Na+ symporters

27
Q

What do Na+ symporters help reabsorb from tubular filtrate?

A

Glucose, amino acids, lactic acids and water soluble vitamins

28
Q

What type of transports does Na+ symporters use?

A

Secondary active transport

29
Q

What is secondary active transport?

A

the movement of materials across a membrane due to the uneven ionic charge

30
Q

Describe intracellular sodium levels

A

They are kept low due to Na+/K+ pumps on the basolateral side

31
Q

Define renal threshold

A

The normal levels of what’s reabsorbed by blood

32
Q

What happens if nutrient concentration is too high compared to renal threshold?

A

it gets filtered into urine

33
Q

What happens if blood glucose exceeds 200 mg/mL (threshold) ?

A

glucose will remain in urine

34
Q

What process is indicative of glucose in urine?

A

glycosuria

35
Q

What disease is a common cause for glycosuria?

A

Diabetes mellitus

36
Q

What is the function of the Loop of Henle?

A

Reabsorption and secretion

37
Q

What is reabsorbed into blood and secreted into tubular fluid in the loop of henle?

A

reabsorbed - water, Na+, K+, Cl-

secreted - urea

38
Q

Describe the concentration of filtrate and blood at the end of the loop of henle and provide the value

A

Hypotonic - lower concentration than blood ~ 100-150 mOsm/mL

39
Q

Where are the symporters in the loop of henle?

A

Thick ascending limb

40
Q

What symporters are found in the loop of henle?

A

Na+, K+ and Cl- symporters

41
Q

How does K+ move across the tubular ?

A

2 K+ moves back into filtrate

42
Q

How does Na+ move across the tubular membrane?

A

3 Na+ is pumped out of the basolateral membrane by Na+ K+ pump with active transport

43
Q

How does Cl- move across the tubular membrane?

A

diffusion

44
Q

How do cations move to the vasa recta from the loop of henle?

A

they move passively due to the negative charge in capillaries

45
Q

What is the thick ascending limb impermeable to?

A

Water

46
Q

What is the function of the early DCT?

A

reabsorption and secretion

47
Q

What is reabsorbed into blood in the early DCT?

A

water, Na+ and cl-

48
Q

Describe the concentration of fluid to blood at the early DCT

A

hypotonic - lower than ~100

49
Q

What is the difference between the early DCT and thick ascending limb of loop?

A

Although they both reabsorb ions, early DCT is more permeable to water

50
Q

Why is the early DCT more permeable to water?

A

obligatory reabsorption of water

51
Q

What is the function of the late DCT and collecting duct?

A

Reabsorption and secreton

52
Q

What does the late DCT and CD reabsorb and secrete?

A

reabsorb - water, Na+ and urea

secrete - k+

53
Q

Describe the concentration of filtrate to blood in the late DCT and CD

A

its variable (either dilute (low bc low ADH) or concentrated ( high bc high ADH)

54
Q

What does the concentration osmolarity depend on in the late DCT and CD?

A

ADH levels!!!!!!!!!!!!!!!!!!!!

55
Q

What are the 2 types of cells in the late DCT and CD?

A
  1. Principal cells

2. Intercalated cells

56
Q

What is the function of principal cells?

A
  • reabsorb Na+ (and water if ADH present)

- secrete K+

57
Q

What is the function of intercalated cells?

A
  • reabsorb K+ and HCO3-

- secrete H+