40 Questions
What is the primary function of the liver in the urea cycle?
To detoxify ammonia by combining it with carbon dioxide
What percentage of urea is reabsorbed into the bloodstream depending on the state of hydration?
40-70%
What is the normal range of urea nitrogen in the blood of a healthy adult?
7-21 mg/dL
Why is the measurement of plasma urea less useful as a test of renal function?
Because it is influenced by extra renal factors
What is the primary purpose of the urea cycle in the body?
To detoxify ammonia and remove excess nitrogen
What is the effect of low urine flow on urea reabsorption?
It increases urea reabsorption
What is the fate of the majority of urea that is filtered by the glomeruli?
It is reabsorbed into the bloodstream
What is the effect of increased protein catabolism on circulating urea concentrations?
It increases circulating urea concentrations
Why is the measurement of plasma creatinine a more reliable test of renal function than the measurement of plasma urea?
Because creatinine is less influenced by extra renal factors
What is the purpose of the BUN test?
To measure the amount of nitrogen in the blood in the form of urea
In which organ is ammonia detoxified to form urea?
Liver
What is the consequence of increased protein breakdown in the body?
Increased ammonia production
Why is the measurement of plasma urea not a reliable test of renal function?
All of the above
What is the primary function of the urea cycle in the body?
To detoxify ammonia
What is the effect of cortisol treatment on circulating urea concentrations?
It increases circulating urea concentrations
What is the fate of the nitrogenous group removed from amino acids?
It is released as ammonia
Why does the rate of urea reabsorption increase when the rate of urine flow is low?
Because the rate of urine flow is inversely related to the rate of urea reabsorption
What is the significance of the BUN test in medical practice?
It measures the amount of urea nitrogen in the blood
What is the consequence of gastrointestinal hemorrhage on circulating urea concentrations?
It increases circulating urea concentrations
What is the relationship between the rate of urine flow and the amount of urea excreted in the urine?
The rate of urine flow is directly proportional to the amount of urea excreted
What is the primary reason for the reabsorption of urea in the kidneys?
To maintain nitrogen balance
What is the consequence of a high urea concentration in the blood?
Toxicity to the body
Why is the measurement of plasma creatinine a better test of renal function than the measurement of plasma urea?
Because creatinine is produced at a constant rate
What is the role of carbon dioxide in the urea cycle?
To detoxify ammonia
What is the effect of a low rate of urine flow on the body?
Increased water reabsorption
What is the fate of the nitrogenous group removed from amino acids?
Converted to ammonia
What is the effect of increased protein intake on the body?
Increased urea production
What is the purpose of the urea cycle in the body?
To detoxify ammonia
What is the consequence of decreased kidney function on the body?
Increased urea concentration in the blood
What is the relationship between the rate of urine flow and the rate of urea reabsorption?
Inversely proportional
What is the primary cause of increased blood urea levels in a patient with severe burns?
Dehydration
Which of the following conditions is associated with decreased blood urea levels?
Pregnancy
What is the likely cause of increased blood urea levels in a patient with ulcerative colitis?
Pre-renal disease
Which of the following is a post-renal disease that can cause increased blood urea levels?
Enlargement of prostate
What is the likely cause of increased blood urea levels in a patient with hematemesis?
Pre-renal disease
What is the primary cause of increased blood urea levels in a patient with Addison's disease?
Adrenal insufficiency
In which condition is blood urea typically lower than in normal non-pregnant women?
Pregnancy
What is a common cause of increased blood urea levels in a patient with ulcerative colitis?
Pre-renal disease
What is the likely cause of decreased blood urea levels in a patient with protein malnutrition?
Decreased protein catabolism
Which of the following is a post-renal disease that can cause increased blood urea levels?
Enlargement of prostate
This quiz covers the process of urea formation in the liver, its transportation and excretion by the kidneys, and factors affecting blood urea levels. Understand how amino acids are deaminated and ammonia is detoxified to form urea. Learn about the role of glomeruli and hydration in urea excretion.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
