Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

+ CAPS 301: Respiratory, Renal, GI, Endocrinology, Reproduction > Functional Anatomy and Renal Blood Flow > Flashcards

Functional Anatomy and Renal Blood Flow Flashcards

1
Q

Overview of Kidney Functions (6)

A
  • regulation of extracellular fluid volume and blood pressure
  • regulation of osmolality of fluid
  • maintenance of ion balance of fluid (Na+, K+, Cl-, Ca2+, PO43- – primarily regulate loss of Na+ and K+)
  • homeostatic regulation of pH (acid-base balance) – by variable excretion of H+ and HCO3-
  • excretion of wastes (ie. creatinine, urea, hormone metabolites, urobilinogen)
  • production of hormones (ie. erythropoietin: stimulates RBC synthesis; renin: important regulator of blood pressure)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is a nephron?

A

one functional unit of the kidney – exchange of substances from tubule back into vascular system

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

How are functions of the kidney accomplished?

A
  • three processes: filtration, reabsorption, secretion (specific movements from blood to tubular fluid, or from tubular fluid to blood – depends on where it is occurring along the nephron)
  • axial specialization
  • coordinate function
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the axial specialization of kidneys?

A

each segment receives product from previous segment

  • composition of fluid in tubule changes as we move through tubule
  • fluid gets exchanged into the next segment, where composition changes again
  • some parts don’t change, depending on conditions
  • some parts are very highly regulatable, and can change in response to different conditions
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the coordinate function of kidney? (2)

A

coordination between multiple segments of one nephron or adjacent nephrons
- kidney tubule folds back on itself, and has some sections where it can communicate with earlier segments

coordination between multiple organs

  • ie. communication between kidney and lungs – helps acid-base balance
  • ie. communication between kidney and liver – when you have higher acid load over sustained period of time
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Gross Anatomy – What are the main components of the renal system?

A
  • kidney (2)
  • ureter (2)
  • urinary bladder
  • urethra
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are ureters?

A

tubes that connect kidney to urinary bladder

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

What does the urinary bladder do?

A

houses urine

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

What is the urethra?

A

where urine exits into environment

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

Where do changes in composition of fluid to-be-excreted occur?

A

all changes occur in outer portion of kidney

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

Kidney Anatomy – What is the renal capsule?

A

thin, tough fibrous capsule that covers surface of kidney

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

Kidney Anatomy – What is the renal cortex?

A

non-striated outer region underneath capsule

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

Kidney Anatomy – What is the medulla?

A

anything that sits under the line that divides the base of that section

  • includes columns
  • more inner portion, but still part of main section of kidney
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Kidney Anatomy – What are renal pyramids? What do they contain?

A

striated pyramidal sections

have many nephrons that change composition of fluid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Kidney Anatomy – What is the renal pelvis?

A

at end of nephron, fluid gets drained into region that connects to renal pelvis, which is an open section inside kidney where fluid sits until it moves down through ureter

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

When can the composition of fluid to-be-excreted no longer be changed?

A

once fluid gets to renal pelvis – this fluid is housed in bladder and excreted through urethra

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How many nephrons do you have?

A

2 million (1 million per kidney)

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

Where are nephrons located?

A
  • some sit with their glomerulus close to border between cortex and medulla
  • some sit with their glomerulus further away
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are the functional units of nephrons? (4)

A
  • filtration
  • reabsorption/secretion
  • regulation
  • excretion
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Where does filtration occur?

A

renal corpuslce

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Where does reabsorption/secretion occur?

A

renal tubule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is reabsorption?

A

movement of substances from tubular fluid back into blood

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

What is secretion?

A

movement of substances from blood to be secreted into tubule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Where does regulation occur?

A

juxtaglomerular apparatus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is the juxtaglomerular apparatus?

A

interface between renal tubule that is just approaching distal tubule, and glomerulus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Where does excretion occur?

A

collecting ducts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

When does excretion occur?

A

when composition of fluid can no longer be changed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What are the 4 tubule segments of the nephron? What parts does each segment consist of?

A
  • proximal tubule (PCT)
  • loop of Henle (PST, tDLH, tALH, TAL)
  • distal tubule (DCT, CNT)
  • collecting duct (CCD, OMCD, IMCD)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What is the structure of the proximal tubule? (3)

A
  • Bowman’s capsule: bulbous section containing capillaries
  • glomerulus: capillary bed found within renal corpuscle
  • lots of bending and folding
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What is the structure of the loop of Henle? (3)

A
  • forms hair-pinned turn as it enters more deeply into medulla of kidney
  • tube is thinner in descending section
  • tube is thicker after turn, when ascending and returning closer to starting point (glomerulus)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What is the structure of the distal tubule? (3)

A
  • convoluted/folded
  • tubule is any tubing past interface between nephron and glomerulus (at beginning of tubule)
  • convergence of many different nephrons at end of distal tubule – drain into collecting duct
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What does the collecting duct do? (3)

A
  • important site in terms of regulation
  • expels fluid into renal pelvis
  • convergence of other nephrons
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What is the renal corpuscle?

A

site of filtration, composed of Bowman’s capsule and glomerulus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What is the macula densa? Where is it?

A

cells on portion of tubule that interfaces with glomerular region (where efferent and afferent arteriole enter and exit)

where thick ascending limb (TAL) transitions into distal convoluted tubule

35
Q

What is Bowman’s capsule?

A

space that fluid (or different substances coming from blood) will be filtered into

36
Q

What are some structural characteristics of Bowman’s capsule? (2)

A
  • basement membrane

- lined by parietal epithelium

37
Q

What are some structural characteristics of glomerular capillary tufts?

A
  • visceral epithelium (podocytes)
  • glomerular basement membrane
  • inside of capillary lined by fenestrated endothelium
38
Q

What does visceral epithelium (podocytes) do?

A
  • adds structural integrity – no interstitial tissue, therefore support is needed
  • very little selectivity that plays role in filtration
  • mesangial cells help change amount of space between podocytes, which impacts surface area available for filtration to occur
39
Q

What happens when mesangial cells are contracted?

A

pull podocytes together → reduced surface area

40
Q

What happens when mesangial cells are relaxed?

A

podocytes move apart → more surface area

41
Q

What does the glomerular basement membrane do?

A

filters – more selective, primary decider about what can pass (ie. size, charge)

42
Q

What is the fenestrated endothelium and what does it do?

A

epithelium glomerular capillary tufts that has large openings between cells

helps make large transport of different substances across membrane possible

43
Q

Where does blood enter and get filtered?

A

enters through afferent arteriole, and filtered once it gets into capillary tuft

44
Q

What happens to substances during filtration in capillary tuft?

A
  • some substances and fluids will cross barrier and enter Bowman’s capsule
  • some substances remain inside vessel, and leave via efferent arteriole and go to vasa recta or peritubular capillaries
45
Q

In later regions of the nephron, why are there principal cells and intercalated cells?

A

allows more diverse and integrated response when fine tuning fluid composition, and regulating pH homeostasis

46
Q

Where in the nephron are cells thinner? Why?

A

descending thin limb and ascending thin limb (as we’re moving into the loop of Henle)

have less mitochondria – not much active transport occurring, therefore cells don’t need them

47
Q

What reabsorption occurs in the proximal straight tubule?

A

67% of Na+ and H2O we reabsorb – bulk movement

48
Q

Do epithelial cells remain the same as we move through the tubule?

A

no – composition of epithelial cells change as we move through tubule

49
Q

What is an important feature of the proximal straight tubule? Why?

A

brush border (microvilli-covered surface)

allows for huge expansion of surface area, which is critical for the large amount of transport occurring in this region

50
Q

What are cells in tubules connected by?

A

tight junctions

51
Q

What do tight junctions help do?

A

determine permeability between cells, across barrier

52
Q

What is the apical membrane?

A

side of cell with tight junctions, and in contact with lumen (continuous with external environment)

53
Q

What is the other side (opposite to apical membrane)?

A

basolateral membrane

54
Q

How do tight junctions change throughout the tubule?

A
  • starts with relatively loose tight junctions, which helps with huge amount of transport occurring
  • very tight junctions in other parts of tubule allow limited (or almost none) movement of substances between cells
55
Q

When do we start seeing more than one cell type in the nephron?

A

starting at the connecting tubule

56
Q

What is filtration?
Where does it occur?
What does it depend on?

A

movement of substances (fluid, glucose, ions, etc.) from blood into tubule

occurs in glomerular capillaries → Bowman’s capsule

highly depends on glomerular basement membrane selectivity

57
Q

What is secretion?

What are other mechanisms along the tubule through which substances can get secreted?

A

movement of substances from blood into tubule after beginning of proximal tubule

substances can still get secreted by active transport, and different types of channels – some places are highly regulated, some places have bulk movement

58
Q

What is reabsorption?

A

movement of substances from tubule back into blood

59
Q

How can fluid or substances be modified? (3)

A
  • by being taken back into blood by reabsorption
  • by adding things to fluid by secretion
  • fluid loss through evaporation, sweating, and other sources
60
Q

Which artery supplies the kidney?

A

renal artery

61
Q

What does all the blood delivered to the kidney pass through?

A

glomerular capillaries

62
Q

What do efferent arterioles supply?

A

depends on where you are in the kidney

  • peritubular capillaries – found superficially in cortical region
  • vasa recta – deeper penetrating vasculature
63
Q

Where does blood exit the kidney?

A

via renal vein

64
Q

What is the filtration fraction?

A

percent of total plasma volume that filters into tubule

65
Q

Describe the general pathway of blood through the kidney.

A

enters kidney → glomerulus → continues on path through kidney → exits kidney

66
Q

Describe how the plasma volume changes along the nephron.

A
  1. 100% when entering afferent arteriole
  2. 20% filters into nephron (from glomerulus into Bowman’s capsule), and 80% continues through glomerulus
  3. > 19% of fluid in nephron is reabsorbed into blood
  4. > 99% of plasma entering kidney returns to systemic circulation via efferent arteriole
  5. < 1% of volume is excreted to external environment
67
Q

What determines the amount of solute excreted?

A

amount filtered - amount reabsorbed + amount secreted

68
Q

What are 3 properties that will allow for assessment of renal blood flow (RBF)?

Is it easy or hard to collect these data?

A
  • urine output – easy
  • blood that gets to kidney – easy, blood sample will closely match composition of blood being delivered to kidney
  • renal vein output – hard, sample needs to be collected before it get mixed back in with the rest of our blood
69
Q

Describe the input = output equation of renal blood flow.

A

input equation: one way in
- renal artery

output equation: two ways out

  • taken back into blood, and leave through renal vein
  • stay in nephron and leave through ureter to be excreted in urine
70
Q

What are clearance values?

A

how well or how much kidney is able to clear substance from blood and excrete it into external environment

71
Q

What are clearance values used for?

A

to estimate RPF – focusing on plasma because it is the fluid part of blood

72
Q

What are the 3 criteria for a substance to be able to be used to estimate RPF?

Why?

A

largely excreted by nephron

  • filtered and secreted, but NOT reabsorbed
  • if it’s going to be excreted, we want it to be completely excreted so that we can know the values between our blood that is being delivered and the urine being excreted

not metabolized/produced by kidney
- can change amounts – by increases in production or break down

not toxic to body

73
Q

Describe para-aminohippuric acid.

A
  • 20% filtered
  • extensively secreted – some PAH goes from blood into Bowman’s capsule
  • < 10% remaining in renal venous blood
74
Q

What is excretion largely dependent on?

A

movement from blood into tubule through secretion mechanism

75
Q

What is RPF used for?

A

to estimate what RBF is

76
Q

How can we assess RPF?

A

by using molecule that is going to be fully excreted – important that it is relying on secretion

substance enters through artery, and is largely going to be cleared by kidneys so that it is essentially 100% excreted

77
Q

What does RPF tell us?

A

how much plasma is delivered to kidney

78
Q

Can the substance used to assess RPF be filtered?

A

can be partially filtered, but it is critical that any non-filtered substance is COMPLETELY SECRETED

79
Q

Why is para-aminohippuric acid (PAH) used to assess RPF?

A

it is partially filtered, but completely secreted (~100% excreted) – relies on secretion for its excretion

ie. if there’s damage to glomerulus and filtration is impacted (ie. 10% being filtered – when normally 20% being filtered, 80% being secreted), because we rely on secretion, we will just secrete more of it

  • 90% leftover will still be secreted, and ultimately we will excrete everything
  • gives good indication of overall picture of how much plasma is actually being delivered to kidney
80
Q

Does RPF change if filtration is impaired?

A

NO – secretion will still allow for complete excretion, even if filtration is reduced

81
Q

What does RPF and GFR together tell us?

A

allows for assessment of renal function (filtration fraction = GFR/RPF)

82
Q

What is glomerular filtration rate (GFR)?

A

how much substance is crossing filtration barrier in glomerulus – gives overall idea of kidney function (filtration fraction)

83
Q

Does filtration matter for RPF?

Does filtration matter for GFR?

A

amount of filtration doesn’t matter for RPF, but really important for GFR

+ CAPS 301: Respiratory, Renal, GI, Endocrinology, Reproduction (32 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions