L14- Urinary Flashcards

1
Q

Function of the urinary system

A

Regulates extracellular fluid (plasma +ISF)

By filtering blood of wastes ➡️ urine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Result(s) of kidneys regulating extracellular fluid

A
  • waste concentration
  • pH (H+ & Hco3)
  • water
    Electrolyte concentration
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the organs found in the urinary system

A

Kidneys, ureters, bladder, urethra

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Kidneys

A

Filters blood of wastes to produce urine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Ureter

A

Transports urine to urinary bladder

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Urinary bladder

A

Stores urine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Urethra

A

Excretes urine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Renal pelvis of kidneys

A

Collects urine before it leaves ureter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Nephron (of kidneys)

A

Functional unit
- forms filtrate and dumps into collecting duct

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the 4 parts of a Nephron

A

Glomerular capsule, proximal convoluted tubule, distal convoluted tubule, the loop of Henle (ascending & descending)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Vascular supply of nephron includes

A

Glomerulus, efferent arteriole , afferent arteriole, peritubular capillaries & vasa recta

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What structures make up a renal corpuscle

A

Glomerular capsule, glomerulus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Fluid flow in kidneys

A

Plasma ➡️ pre-urine filtrate ➡️ urine
(Glomerous). (Nephron). (Leaves collecting duct)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Filtration membrane includes

A
  • Capillary fenestrations
  • Basement membrane
  • filtration slits
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Filtration membrane is

A

Filtration of blood that produces pre-urine filtrate in glomerular capsule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Juxtaglomerular apparatus (JGA) includes

A

Juxtaglomerular cells & macula dense cells

  • is the triangle area b/w afferent and efferent arterioles
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are the 2 types of nephrons

A

Cortical nephron & juxtamedullary nephron

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Juxtamedullary nephron

A
  • less numerous (20%)
  • long loop of henle = goes into medulla & cortex

2nd capillary bed= peritubular capillaries & vasa recta

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Cortical nephron

A
  • more numerous (80%)
  • short loop of henle ( mostly in cortex of kidney)

2nd capillary bed = peritubular capillaries

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are the steps of urine formation

A
  1. Filtration
  2. Reabsorption
  3. Secretion
  4. Concentration
  5. Excretion
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Filtration

A

Blood ➡️ tubule

  • filtrates everything in the blood but cells & proteins ( too big)
  • occurs at renal corpuscle= glomerular corpuscle
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Filtrate =

A

Plasma - cells & proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What percent of filtrate is reabsorbed regardless of a persons state of hydration

A

99% of filtrate reabsorbed & 1% excreted as urine

24
Q

What is the total blood volume of an average adult?

A

5.5 liters of blood

25
Q

How much blood is filtered a day?

A

180L of filtrate / day

26
Q

Reabsorption

A

Tubule ➡️ blood

  • reabsorbed what we want to keep
27
Q

Where does reabsorption occur and what is absorbed?

A

65% at proximal convoluted tubule
20% at descending loop of henle

  • na+, cl, h2o
28
Q

What percentage of glucose and amino acids is reabsorbed and where are they reabsorbed at?

A

100% reabsorbed at proximal convoluted tubule

  • Cotransport w/ Na+
29
Q

Why is glucose found in urine for individuals with diabetes?

A

They reach the glucose transport maximum, meaning they have too much glucose in the blood therefore some needs to be excreted out through urine

30
Q

Secretion ( active process)

A

Blood ➡️ tubule
@ distal convoluted tubule
- fine tunes blood removing excess H+ , K+ & xenobiotics, metabolites

31
Q

Removal of excess h+ maintains ______

A

Ph

32
Q

Removal of excess k+ maintains _________________

A

Electrophysiology

33
Q

How does our body remove chemicals that it’s never seen before?

A

Go to liver ➡️ converting it to soluble form then removed by “multi-specific” transporters in kidneys

34
Q

Concentrating urine is important

A

To maintain blood osmolarity

35
Q

How do we concentrate urine

A

Pulling water out of collecting duct by osmosis ( na+ goes h2o follows)

36
Q

Driving force for osmosis is

A

Salt gradient in the renal medulla interstitial fluid

37
Q

What is the osmolarity of the renal cortex? What is the osmolarity of the renal medulla?

A

Cortex = 300

Medulla = 600-1200

38
Q

Loop of Henle _______ salt gradient

A

Creates

39
Q

Vasa recta ___________ salt gradient by taking in h2o

A

Maintains

40
Q

Collecting duct _________ salt gradient to concentrate urine

A

Uses

41
Q

How does ADH Concentrate urine

A

Antidiuretic hormone (ADH) inserts aquaporins into collecting duct

+ ADH = concentrated urine up to 1200mOm
- ADH = dilate urine @ 100mOsm

42
Q

Counter current multiplier

A

Mechanism used to create salt gradient - loop of henle

43
Q

Counter current exchanger

A

Mechanism that maintains salt gradient - Vasa recta

44
Q

Why must we concentration urine?

A

Prevent dehydration

45
Q

Counter current means

A

Ascending and descending limb moves in opposite directions

46
Q

The descending limb of Henle

A
  • is passive
  • it must lose water to assist in formation of salt gradient in Medulla
47
Q

Ascending loop of Henle

A

Is active
- forms salt gradient in renal medulla

48
Q

What is the problem of water leaving desending loop of
Henle? How is this solved?

A

Water dilutes gradient in renal Medulla

Solution = water is picked up in the ascending vasa recta

49
Q

The descending vasa recta

A

Picks up salt from gradient in medulla ➡️ creating salt gradient in vasa recta

50
Q

Ascending vasa recta

A

Uses the salt gradient to pick up water from medulla preventing dilution of salt gradient ➡️ returning salt to medulla to maintain salt gradient

51
Q

In the complete absence of ADH, what will the osmolarity of urine be?

A

100mOm - filtrate enters collecting duct @ 100mOm therefore when we are over hydrated no ADH with be present to help retain water

52
Q

In the Presence of ADH, what is the maximal osmolarity that the urine can achieve?

A

1200 mOm - it enters collecting duct at 100, but as it passes through the more dehydrated the person is the more ADH present inserting more Aquaporins to retain water

53
Q

What causes ADH to stimulate the insertion of aquaporins

A

Exocytosis

54
Q

What removes aquaporins

A

Endocytosis

55
Q

What are the 2 causes of increased osmolarity?

A
  1. Dehydration
  2. Increased salt intake
56
Q

What are the two ways to fix osmolarity?

A
  • drink water
  • hold on to water by concentrating urine
57
Q

NFL for dehydration

A

Low water intake = stimulus
➡️ increase osmolarity ➡️ osmoreceptors shrink in hypothalamus ➡️ posterior pituitary increase ADH (aquaporins) ➡️ kidneys increase h2o reabsorption ➡️ less water excreted in urine