Brainscape's Knowledge GenomeTM

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


See full index

Urinary > Renal structure and function: macromolecules > Flashcards

Renal structure and function: macromolecules Flashcards

1
Q

What are the three main actions that occur in the nephron?
1.
2.
3.

A

Filtration
Secretion
Absorption

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

What is filtered from the glomerulus?

A

Plasma

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

Where is the major site of reabsorption in the nephron?

A

PT

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

What are the main components that are reabsorbed?

A

Na

Glucose

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

Where is the major site of secretion in the nephron?

A

DT

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

What are the main components that are secreted?

A

K

Organic acids

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

What are the two different types of nephron?

A

Cortical

Juxtamedullary

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

How does blood enter the glomerulus?

A

Via the afferent arteriole

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

How does blood exit the glomerulus?

A

Via the efferent arteriole

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

Which of the following is largest, afferent arteriole or efferent arteriole?

A

Afferent

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

_____ cells provide support and structure to the glomerulus.

A

Mesangial

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

What would happen if the podocyte pedicles get further apart?

A

Lose the ability to effectively filter the ultrafiltrate, meaning they will allow large molecules such as proteins and cells to exit the capillaries

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

Outline the course the ultrafiltrate passes to become urine.

A

Glomerulus, Bowman’s space/urinary space, PT, LOH, DT, CD, renal papilla renal pelvis, ureter, bladder, urethra

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

The endothelium of the glomerular capillaries contains _____ that allow the passage of filtrate from the capillaries.

A

Fenestrations

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

What properties of the basement membrane make it a barrier to filtration?

A

It is a thick acellular negatively charged glycocalyx

Proteins within the plasma tend to be negatively charged, therefore the basement membrane repels them

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

What effect does hypertension have on the basement membrane?

A

It increases the thickness of it to try and oppose the increase in pressure being exerted on it by high blood pressure

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

Apart from filtration, what other functions do pedicels have with regards to the capillaries?

A

Support the capillaries

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

What size molecules can easily pass through the filtration apparatus?

A

Molecules less then 7000 daltons

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

Glomerular filtrate is essentially a _____ free filtrate of plasma.

A

Protein

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

Name five molecules that the glomerular filtrate contains.

A 
Glucose
Amino acids
Hormones
Salts
Vitamins
Water
Urea
(Plasma proteins, but very little)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

In the normal animal, what should be reabsorbed from the glomerular filtrate?

A 
Glucose
Amino acids
Hormones
Salts
Vitamins
Water
Plasma proteins (if present)
(Some urea)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is glomerular filtration rate?

A

The volume of fluid filtered from the glomerular capillaries to the Bowman’s space per minute

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

GFR can be used as a measure of _____ _____.

A

Renal function

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

GFR is not measured in practice easily and tends to be done more in research. Why is this?

A

Variations in animal based on size and age of the animal
GFR will be different in an animal that is very lean compared to an animal that has lots of fat
Other tests are more appropriate for looking at renal function in practice.

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

What part of the nephron follows the Bowman’s capsule?

A

PT

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

What is the main function of the PT?

A

Bulk reabsorption

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

How are the PT’s adapted for bulk absorption?

A

Microvilli on the apical surface of the epithelial cells for bulk absorption
Basal striations on the basal membrane of the epithelial cells, also have lots of Na/K ATPases for active uptake of ions, also have lots of mitochondria as very metabolically active area

28
Q

The majority of reabsorption of the ultrafiltrate occurs in the PCT, roughly how much is this and where in the kidney does it occur?

A

65-80%

In the outer cortex

29
Q

What type of epithelium is present in the PTs?

A

Thick, tall columnar epithelium

30
Q

In what region of the kidney does most reabsorption occur?

A

(Outer) cortex

31
Q

What type of nephrons are mostly involved in reabsorption?

A

Cortical

32
Q

Why does the majority of reabsorption occur in the cortex?

A

Cortex has a better blood supply than the medulla

33
Q

Most reabsorption is generally _____, but it is the action of Na pumps in the _____ _____ and the coupling of Na ions to substances to be reabsorbed that allows this passive diffusion to occur.

A

Iso-osmotic

Basal membrane

34
Q

Why is primary active reabsorption known as primary active reabsorption?

A

Transport through the basolateral membrane requires energy.

35
Q

Why is secondary active resorption known as secondary active resorption?

A

The active membrane transport occurs in the apical membrane due to the action of the Na/K pump on the basolateral membrane, think of it as indirect active transport.

36
Q

Which types of active reabsorption does most rebsorption occur by?

A

Primary

37
Q

In primary active reabsorption, Na is _____ pumped _____ of the cell and K is pumped ____ to the cell. The results in a _____ Na concentration within the cell and a ____ Na concentration in the _____. From the _____, Na ions along with water and the substances dissolved in water diffuse into the peritubular capillaries.

A 
Actively
Out
In
Low
high
Interstitum
Interstitium
38
Q

As a result of the movement of ions across the cell membranes, the epithelial cells are _____ relative to the surrounding ECF.

A

Negative

39
Q

There are two factors that promote the diffusion of Na from the tubular lumen into epithelial cells, what are they?
1.
2.

A

Large Na difference across the cell, i.e. high concentration in the tubular lumen and low concentration inside the epithelial cells
Negative membrane potential of the cell

40
Q

Na/K ATPase pumps are not present on the apical surface of the PT cells, why is this?

A

Prevents Na from being pumped back into the tubular lumen

41
Q

Renal Na transport always proceeds from the _____ lumen to the _____ _____.

A

Tubular

Peritubular capillaries

42
Q

Secondary active absorption utilises the concentration gradient formed from the action of the Na/K pump on the basolateral surface of the epithelial cells to promote uptake from the apical membrane of the cell. This means that molecules such a glucose get a ‘free ride’ into the cell when Na is transported into the cell.
What is the name for the transporters that allow entry of sodium and another substance into the epithelial cells?

A

Symporters

43
Q

What are the names of the carrier proteins that pump Na into the cell and other molecules out of the cell?

A

Anti-porters

44
Q

What is the name of the receptors that reabsorb filtered proteins by endocytosis?

A

Megalin and cubulin

45
Q

Why is there not tight regulation of the processes of absorption and secretion

A

The solute gradients are very small, therefore not a lot of molecules will move across, so they do not need controlling.

46
Q

How much of the glucose and amino acids in the filtrate are reabsorbed by the end of the PCT?

A

100%

47
Q

How much of the water and electrolytes present in the filtrate are reabsorbed by the end of the PCT?

A

65-80%

48
Q

How much phosphate is reabsorbed from the filtrate at the end of the PCT?

A

Around 80%

49
Q

How much urea is reabsorbed from the filtrate at the end of the PCT?

A

Around 50%

50
Q

Why is high kidney flow/filtration rate needed to prevent uremia?

A

50-60% urea is reabsorbed, so high kidney filtration rates are needed to prevent uraemia.

51
Q

Why is important that urea is appropriately removed?

A

Urea is moderately lipid soluble so can easily cross cell membranes. Lipid-soluble toxins are hard to get rid of, The liver will convert lipid-soluble toxins to water soluble toxins to be excreted by the kidneys. If it is not removed appropriately, uremia (pre-renal azotaemia) will develop.

52
Q

What causes pre-renal azotaemia?

A

Reduced blood flow to the kidneys resulting in improper removal or urea/nitrogen containing products leading to a build up of them in the blood.

53
Q

Glucose is reabsorbed in the PT coupled with _____ by _____ _____ _____.

A

Na

Secondary active reabsorption

54
Q

Glucose enters the cells via Na-glucose _____.

A

Symporters

55
Q

Na-glucose symporters can become saturated, i.e. they have reached their transport maximum. What would happen when this occurs?

A

More glucose will be excreted

56
Q

Briefly explain what Fancoi syndrome is.

A

PT is damaged, therefore this is limited to no reabsorbtion occurring. As a result, you see isosothenuric urine, i.e. urine with the same USG as plasma.

57
Q

Name three causes of glomerular disease.
1.
2.
3.

A

Diabetic nephropathy
Hypertension
Glomerulosclerosis (fibrosis of the glomerulus)

58
Q

What is nephrotic syndrome?

A

A disease that causes loss of protein in the urine.

59
Q

What are the clinical signs of nephrotic syndrome?

A

Weight loss (due to the animal having to use its own body reserves to make up for the protein it is losing from the blood in the urine), oedema (due to the lack of COP in the blood vessels, so water is drawn into the tissue instead), ascities (see above) and hypoalbuminaemia (due to chronic loss of protein in the urine)

60
Q

How would you diagnose nephrotic syndrome?

A

Urinalysis, lots of protein in the urine
Blood biochemistry
History

61
Q

What is the value that means an animal has proteinuria on urine protein:creatinine?

A

> 0.4

62
Q

What are amyloids?

A

Clumps of proteins that are bound together.

63
Q

How do amyloids contribute to nephrotic syndrome?

A

Amyloids block the glomerular basement membrane resulting in loss of normal barrier proteins, leading to proteinuria.

64
Q

How does chronic proteinuria lead to renal failure?

A

This triggers renal inflammation which will eventually result in renal failure (not sure of exact mechanism)

65
Q

How does chronic proteinuria lead to hypertension?

A

Chronic proteinuria leads to hypovolaemia due to the reduced COP in the vessels. This will then activate the RAAS, which can lead to hypertension.

Urinary (11 decks)

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