Brainscape's Knowledge GenomeTM

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


See full index

Tri B > Renal System > Flashcards

Renal System Flashcards

1
Q

Where are the kidneys and what size are they?

A

Located on inner surface of lower back.

Small organs 1% of body weight.

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

What % of Cardiac output to kidneys receive?

A

25%

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

Discuss the internal structure of the kidney?

A

Outer renal capsule surrounds renal cortex surrounds renal medulla.
Renal medulla composed of renal pyramids. The renal pyramids join to the renal papilla at the minor calyx which joins to major calyx and then renal pelvis which leads to the ureter.
Permeating the pyramids are nephrons which are the functional units of the kidneys

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

What are kidney nephrons?

A

The function unit of the kidney. An intricate epithelial tube of simple cuboidal epithelia specialised for secretions and absorption.

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

Discuss the structure of a nephron.

A

Afferent Arteriole - Glomerulus - Efferent arteriole.
Glomerulus surrounded by glomerular capsule - Proximal convoluted tubule - loop of henle descending and ascending- distal convoluted tubule - collecting duct - renal papilla

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

Discuss the cell specialisation of the proximal convoluted tubule

A

Cells have microvilli on apical surface, joined by tight junctions.
Cells have brush border so huge surface area. This promotes reabsorption of water nutrients into blood and secretion of other substances back into systemic circulation

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

Discuss the filtration membrane of the glomerulus blood vessels.

A

The blood vessels have fenestrations in the squamos epithelia surrounded by a basement membrane.
Podocytes are cells which surround blood vessels which wrap vessels forming pedicels which leave gaps exposing the basement membrane. These are filtration slits.

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

What does the filtration membrane at the glomerulus do?

A

Large particles like rbc & proteins cannot cross barrier but water nutrients, glucose, ions can.

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

What does the loop of henle do?

A

Site of water reabsorption to adjust osmotic gradient that allows water & sodium reabsorption and to concentrate urine in collecting duct

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

What does the distal convoluted tubule do?

A

Further reabsorption of material including BICARBONATE ions as well as secretion of hydrogen. This adjusts blood ph assisting to maintain acid base balance.

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

What does the collecting duct do?

A

Serves multiple nephrons. Final site of water reabsorption determining final concentration of urine

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

How many litres of water are filtered each day?

A

180 Litres

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

How much of filtered water is reabsorbed

A

99%

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

How many grams of sodium are filtered per day?

A

630g

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

How much of filtered sodium is reabsorbed?

A

95.5%

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

How many grams of glucose are filtered each day?

A

180g

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

How much of filtered glucose is reabsorbed?

A

100%

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

How many grams of urea are filtered per day?

A

54g

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

How much of filtered urea is reabsorbed?

A

44%

20
Q

How much water, sodium, glucose, urea is excreted each day?

A

Water - 1.8 litres
Sodium - 3.2g
Glucose - 0
Urea - 30g

21
Q

What happens to the substances that are reabsorbed and those that are not?

A

Reabsorbed enter systemic circulation, the rest is excreted as urine

22
Q

What do tight junctions in the nephron do?

A

Tight junctions restrict diffusion between lumen and extracellular space. Make nephrons watertight.

23
Q

What is the Glomerulus?

A

Part of nephron. A network of capillaries with a relatively high bp. The high bp works to push fluid out of capillaries into space of bowman capsule

24
Q

What is reabsorbed in the proximal convoluted tubule?

A

Water, glucose, Vitamin C, some salts

75% of filtered sodium is reabsorbed here

25
Q

What are the three main processes involved in urine formation?

A

Filtration
Reabsorption
Secretion

26
Q

What is the Glomerular Filtration Rate?

A

The measure of how much filtrate is produced. About 180 Litres a day in a normal person.
GFR is an important indicator of kidney health/ function

27
Q

How is eGFR (estimation of GFR) standardised?

A

By correcting for body surface area.

28
Q

What drives filtration?

A
  • The sieve like walls of the capillary walls
  • Pressure gradients resulting from glomeruli bp being high compared to bowman capsule (assisted by presence of plasma proteins in capillary blood)
29
Q

What is glomerular capillary blood pressure?

A

60 mmHG

This pushes blood out

30
Q

What is the bowman capsule blood pressure?

A

20mmHg

This acts to push fluid back into capillaries

31
Q

What is the Capillary osmotic pressure (plasma proteins)

A

30mmHg

Acting to pull water from bowman capsule back into capillaries

32
Q

What is the overall filtration pressure out of the glomerular capillaries?

A

10mmHg

Acting in outward direction.

33
Q

Describe the reabsorption of sodium ions in the proximal convoluted tubule?

A

75% OF S

34
Q

Describe the reabsorption of sodium ions in the proximal convoluted tubule?

A

75% OF Sodium ions reabsorbed here.

It is an ACTIVE PROCESS using membrane pumps and ATP.

35
Q

What ions are taken along with sodium ions during reabsorption and why?

A

Chloride ions are dragged along with sodium ions as they are negatively charged and help to maintain eletrochemical neutrality by counteracting the positively charged sodium ions.

Water is also reabsorbed to maintain osmotic balance.

36
Q

What is the maximum amount of material that can be transported from the filtrate back into plasma known as?

A

The Transport Maximum (Tm)

Once beyond the transport maximum no more can be reabsorbed.

37
Q

At what point would a substance such as sodium appear in the urine?

A

Only once the transport maximum for sodium has been reached and exceeded.

38
Q

Discuss diabetes mellitus in terms of glucose excretion and the transport maximum.

A

Glucose not absorbed and level in plasma increases.
Filtered glucose increases and exceeds transport maximum. Transport systems overwhelmed.
Glucose now appears in urine

39
Q

What is glucose in the urine called?

A

Glycosuria

40
Q

Why does glycosuria result in increased urine volume?

A

The presence of glucose in the urine exerts an osmotic gradient pulling water into the tubule. Thus there is an increased volume of urine.

41
Q

What is secreted in the distal convoluted tube?

A

Potassium Ions
HYDROGEN Ions
Ammonia
These substances are now added to the filtrate for excretion

42
Q

What does the reabsorption of bicarbonate and secretion of hydrogen in the distal convoluted tube achieve?

A

Bicarbonate is alkaline.
Hydrogen is acidic.
This process increases the acidity of urine and in REGULATING PLASMA PH (acid base balance)

43
Q

What is the normal PH of plasma?

A

7.4

44
Q

What hormone influences the collecting duct?

A

Anti-diuretic hormone which helps to reabsorb water

45
Q

What does ADH do in terms of the collecting duct?

A

Influence the volume and concentration of urine. Increases water reabsorption and fluid retention in plasma.

This is important in regulating plasma volume and therefore blood pressure.

46
Q

What stimulates release of ADH from the posterior pituitary gland?

A

Dehydration, blood loss, shock

47
Q

Discuss dehydration and ADH as a negative feedback loop?

A

Dehydration
ADH released
Water reabsorption increased and plasma fluid retention increased.
Increases blood volume

Increased blood volume = less ADH released

Tri B (13 decks)

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