Brainscape's Knowledge GenomeTM

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


See full index

S1 Pharmacology > Urea + Electroylte Tests > Flashcards

Urea + Electroylte Tests Flashcards

1
Q

Which components are typically filtered by the kidneys?

A
  • Low molecular weight (LMW) components are filtered by the kidneys.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the normal glomerular filtration rate (GFR) in humans?

A
  • The normal GFR is approximately 120 mL/min.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the typical range of urine production in a 24-hour period?

A
  • Normal urine production is between 1–2 liters per day
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Why is glomerular filtration rate (GFR) important?

A
  • GFR is a key indicator of overall health and is particularly important for assessing kidney function and drug excretion.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Which substance is commonly used as a proxy marker for GFR?

A
  • Creatinine is used as a proxy marker for GFR because it is completely filtered by the kidneys and not reabsorbed.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is creatinine?

A
  • Creatinine is a waste product formed from the normal breakdown of creatine, a compound essential for muscle energy metabolism
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How is creatinine eliminated from the body?

A
  • Creatinine is filtered out of the blood by the kidneys and excreted in urine.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Why does muscle mass affect creatinine levels?

A
  • Muscle mass affects creatinine levels because creatinine production is proportional to muscle metabolism, meaning individuals with more muscle mass produce more creatinine
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What happens to the majority of creatinine in the kidneys?

A
  • About 90–95% of creatinine is filtered through the glomerulus.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What happens to the remaining 5–10% of creatinine in the kidneys?

A
  • the remaining 5–10% of creatinine is secreted into the urine by the cells of the distal tubule.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the Cockcroft-Gault equation used for?

A
  • The Cockcroft-Gault equation is used to estimate creatinine clearance (CrCl), which reflects kidney function.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the Cockcroft-Gault equation ?

A
  • CrCl (mL/min) = (140-age) x weight x (1.23 male/1.04 female) / SrCr (μmol/L)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What creatinine clearance (CrCl) ranges correspond to kidney impairment?

A

• 50–20 mL/min: Mild impairment
• 20–10 mL/min: Moderate impairment
• <10 mL/min: Severe impairment

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

Why is creatinine clearance (CrCl) inherently inaccurate?

A
  • CrCl slightly overestimates GFR because a small amount of creatinine is secreted by the renal tubules
  • its accuracy is influenced by various patient factors.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

In which patients is CrCl particularly inaccurate?

A

• Patients with significant muscle wastage.
• Patients with low muscle mass.
• Cachexic (severely malnourished) patients.
• Patients with rapidly changing serum creatinine levels.

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

What is acute kidney injury (AKI)?

A
  • AKI is a sudden decline in kidney function, characterized by reduced glomerular filtration rate (GFR)
  • impaired fluid and electrolyte balance, and accumulation of waste products in the blood.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are the primary causes of AKI?

A
  1. Pre-renal: Reduced blood flow to the kidneys (e.g., dehydration, hypotension).
    1. Intrinsic: Direct damage to kidney tissues (e.g., acute tubular necrosis, glomerulonephritis).
    2. Post-renal: Obstruction of urine outflow (e.g., kidney stones, enlarged prostate).
18
Q

How is urea produced ?

A
  • in the liver
  • after the delaminating of amino acids
19
Q

How is urea cleared form the body ?

A
  • by the golmerular filtration
  • it is a major source of N loss from the body
20
Q

Is urea reabsorbed in the body ?

A
  • some urea is reabsorbed by passive tubular reabsorption
21
Q

What does high level of urea indicate ?

A
  • dehydration
  • gastric blood loss
  • infection
22
Q

What does low level of urea indicate ?

A
  • oedema
  • pregnancy
  • low protein diet
23
Q

Where is potassium primarily found in the body?

A
  • Potassium is primarily an intracellular cation, meaning most of it is found inside cells.
24
Q

Why are serum potassium (K+) levels important?

A
  • Serum K+ levels are crucial because they influence membrane potential and can cause rapid changes in cell function, particularly in nerve and muscle cells.
25
Q

What percentage of potassium is available for exchange in the body?

A
  • About 90% of the total body potassium is available for exchange.
26
Q

Where is the remaining 10% of potassium in the body found?

A
  • the remaining 10% of potassium is bound in red blood cells (RBCs) and other tissues.
27
Q

How are potassium and sodium movements related in the kidneys?

A
  • K and Na movements are closely related because as Na is actively reabsorbed, K moves into the filtrate to maintain membrane potential balance.
28
Q

How do hydrogen ions (H+) move in relation to potassium in the kidneys?

A
  • H+ ions tend to move with potassium in the renal tubules
  • but this depends on the ability of the tubular cells to secrete H+.
29
Q

What happens to potassium levels in acidosis?

A
  • hyperkalemia (high potassium)
  • because hydrogen ions shift into cells, and potassium shifts out to maintain charge balance.
30
Q

What happens to potassium levels in alkalosis?

A
  • hypokalemia (low potassium)
  • hydrogen ions shift out of cells, and potassium moves into cells to maintain balance
  • less in bloodstream
31
Q

What is the normal range for potassium in the body
?

A

3.6 - 5.2 mmol/L

32
Q

What happens when the water content of the blood is low?

A
  • blood water content is low (due to too much salt or sweating)
  • brain produces more ADH, causing the kidneys to reabsorb more water
  • resulting in low urine output / less water in urine (small volume of concentrated urine).
33
Q

What happens when the water content of the blood is high?

A
  • blood water content is high (due to drinking too much water)
  • the brain produces less ADH
  • leading to low reabsorption of water by the kidneys and high urine output (large volume of dilute urine).
34
Q

What is the definition of hyponatremia?

A
  • serum sodium concentration of less than 135 mmol/L.
  • Treatment is typically required when serum sodium is below 120 mmol/L.
35
Q

What is the most common cause of hyponatremia?

A
  • rarely due to low sodium intake but is usually caused by defective homeostatic mechanisms
  • such as the inability to properly regulate water and sodium balance.
36
Q

What is the underlying issue in most cases of hyponatremia?

A
  • often an excess of water relative to sodium, meaning there is more water than sodium in extracellular fluid
37
Q

What is required to develop hyponatraemia ?

A
  • Source of free water
    • Impaired ability of the urine to excrete dilute urine.
    • Reduced solute intake
    • Poor renal function
38
Q

What are symptoms of people with hyponatraemia ?

A
  • Cerebral edema
    • Confusion
    • Seizures
    • Coma
    • Brain herniation (in severe cases)
39
Q

What is hypernatraemia ?

A
  • marked decrease in water relative to sodium.
    • Does not occur unless there is impaired thirst
    mechanisms or lack of access to water
    • Can be cause by drugs or (usually) by drinking sea
    water
40
Q

What is the role of glomerular filtration in protein loss?

A
  • the glomerular filtration system is designed to filter out large molecules, such as proteins, and prevent them from crossing into the filtrate.
41
Q

What is the normal range for protein loss in the urine?

A
  • A protein loss of <150 mg/day is considered normal.
42
Q

What is microalbuminuria?

A
  • Microalbuminuria refers to the loss of albumin in the urine at levels of >30 mg/L.

S1 Pharmacology (33 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions