Brainscape's Knowledge GenomeTM

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


See full index

Medical Science - Physiology > Kidney Function > Flashcards

Kidney Function Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards USMLE® Step 1 flashcards
1
Q

How many nephrons in the kidneys?

A

2.5 million

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

What are the three stages of urine formation and where do they occur?

A

Filtration (renal corpuscle)
Reabsorption (convoluted tubule)
Secretion (distal convoluted tubule)

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

What happens in filtration?

A

Blood pressure forces water and solutes across walls of glomerular capillaries

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

What happens in reabsorption?

A

Water and solutes removed from filtrate across tubular epithelium into peritubular fluid (fluid surrounding tubule), via diffusion or carrier proteins
Reabsorbed substances eventually reenter blood

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

What happens in secretion?

A

Solutes transported from peritubular fluid across tubular epithelium into tubular fluid

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

What is the net filtration rate?

A

Net filtration pressure acting across glomerular membrane, depends on:

  • Glomerular hydrostatic pressure
  • Capsular hydrostatic pressure (acts against)
  • Colloid osmotic pressure (acts against)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What effects the glomerular filtration rate?

A

Renal blood flow

Arteriolar constriction

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

What is the glomerular filtration rate (GFR)?

A

Amount of filtrate produced by kidneys each minute

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

What is the structure of the glomerular membrane?

A
  • Endothelial layer of capillary
  • Basement membrane
  • Layer of epithelial cells lining capsule
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is clearance?

A

The volume of plasma passing through the kidneys per unit time to produce the amount of a solute in urine

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

When does clearance equal the GFR?

A

When a substance is not reabsorbed from urine or secreted into the tubules

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

How can GFR be accurately measured?

A

Inulin

- An inert polysaccharide not metabolised in the body and neither reabsorbed or secreted by tubules

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

What is the creatinine clearance test?

A

Compares creatinine level in blood and urine
A value of 100 means kidneys working 100%
(Creatinine elimination per hour/plasma creatinine conc.)

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

What is countercurrent multiplication?

A

Exchange of substances between descending (thin) and ascending (thick) segments of a nephron

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

What is the purpose of the countercurrent?

A
  • Effectively reabsorbs water and solutes

- Establishes concentration gradient in peritubular fluid that passively reabsorbs water from collecting ducts

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

How does the countercurrent work?

A
  • Na and Cl ions actively pumped out from ascending loop
  • Interstitial fluid ion concentration increases
  • Osmotic movement of water out of thin loop
17
Q

How is concentrated urine produced following dehydration?

A
  • Increase in osmotic pressure detected by osmoreceptors in hypothalamus, so ADH produced by pos. pituitary gland
  • ADH increases reabsorption of water in collecting tubules
  • Blood is diluted, osmotic pressure decreases, ADH release decreases
18
Q

What is it called when the body produces a large volume of urine?

A

Diuresis

19
Q

What does ADH do?

A

Increases the permeability of the collecting ducts to water

20
Q

What controls osmolarity?

A

Concentration of sodium, which is controlled by ADH, thirst centre and aldosterone

21
Q

Where is aldosterone produced?

A

Adrenal glands

22
Q

What does aldosterone do?

A

Increases K+ secretion into distal and collecting tubules

23
Q

What is Addison’s disease?

A

Destruction of adrenal gland - Hyperkalaemia

- Cardiac arrhythmias

24
Q

What is the effect of an adrenal gland tumour?

A

Very low blood potassium

  • Failure of nerve transmission due to hyperpolarisation of membranes
  • Hypokalaemia
25
Q

What regulates aldosterone release?

A
  • Extracellular K+ concentration
  • Renin-angiotensin system
  • Body sodium ion concentrations
  • ACTH
26
Q

What is ACTH?

A

Hormone released by ant. pituitary which controls release of aldosterone

27
Q

From where is renin released?

A

Juxtaglomerular apparatus (distal tubule)

28
Q

What does renin do?

A

Converts angiotensinogen (plasma protein from liver) to angiotensin I

29
Q

How is angiotensin I converted to angiotensin II?

A

By convertase enzyme in the lung

30
Q

What does angiotensin II do?

A
  • Stimulates release of aldosterone
  • Vasoconstrictor
  • Stimulates thirst

Medical Science - Physiology (11 decks)

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