BLD 324 EXAM QUESTIONS AND ANSWERS WITH COMPLETE
SOLUTIONS VERIFIED GRADED A++
Discuss urine composition and its variation
Varies on individual's:
Diet
Physical activity
Health
Urine is ultra-filtrate of plasma with selected solutes reabsorbed, other solutes secreted
Final water volume determined by the body's state of hydration
Excreted urine 94% water and 6% solutes
Discuss the substances that are excreted by the kidney
Soluble metabolic wastes
Organic acids and bases
Exogenous
Radiographic contrast media
Drugs
Metabolism of proteins and nucleic acids yields:
Soluble substances such as urea, creatinine, uric acid, and other inorganic solutes
Compare and contrast osmolality and specific gravity and discuss their
determined factors
,Osmolality and specific gravity measurements are used to assess the quantity of
solutes present in urine, which reflects the ability of the kidneys to produce a
concentrated urine
Their relationship is close but not linear
Osmolality
Osmoles per kilogram (Os/kg)
1 mOsm=1 mmol of particles
1 mmol urea= 1 mOsm
1 mmol NaCl= 2 mOsm
Affected by solute number
Final osmolality is determined in distal and collecting tubules when ADH is present
Normal urine osmolality is 1 to 3 times that of plasma
300 mOsm 100 mOsm 300 mOsm
Compare and contrast specific gravity and discuss their determined factors
Specific gravity
Comparison of density of urine to that of water
Normal ranges: 1.002-1.035
Above 1.04 is physiologically impossible unless excreting high-molecular-weight
substance
Depends on number of particles and mass
Fluid intake
State of hydration
, Explain the causes of extremely high gravity value of the urine specimen and how
to handle it
Higher than 1.050
Happens when urein has high-molecular-weight substance
X-ray dye
Substances are infused into patients and excreted in the urine
Consider a contaminant and don't indicate disease or disorder
New specimen should be collected latte
Explain why urea and creatinine can be used to monitor renal function
Large concentration in urine
Easy to measure
Precision and reliability of each measurement method are known and well documented
Discuss the osmolality change of the urine during its formation process. State the
effects of the ADH
Osmolarity remains unchanged (isometric at ~300 mOsm) until the filtrate reaches the
thin descending limb of the loop of Henle
Filtrate in the Loop of Henle becomes hypersomatic and when it enters the distal
tubules is 100 mOsm
Final osmolarity of urines determined in the distal tubules and collecting
When ADH is present, the filtrate is again 300 mOsm
Define polyuria, oliguria, and anuria. Discuss and differentiate their causes.
SOLUTIONS VERIFIED GRADED A++
Discuss urine composition and its variation
Varies on individual's:
Diet
Physical activity
Health
Urine is ultra-filtrate of plasma with selected solutes reabsorbed, other solutes secreted
Final water volume determined by the body's state of hydration
Excreted urine 94% water and 6% solutes
Discuss the substances that are excreted by the kidney
Soluble metabolic wastes
Organic acids and bases
Exogenous
Radiographic contrast media
Drugs
Metabolism of proteins and nucleic acids yields:
Soluble substances such as urea, creatinine, uric acid, and other inorganic solutes
Compare and contrast osmolality and specific gravity and discuss their
determined factors
,Osmolality and specific gravity measurements are used to assess the quantity of
solutes present in urine, which reflects the ability of the kidneys to produce a
concentrated urine
Their relationship is close but not linear
Osmolality
Osmoles per kilogram (Os/kg)
1 mOsm=1 mmol of particles
1 mmol urea= 1 mOsm
1 mmol NaCl= 2 mOsm
Affected by solute number
Final osmolality is determined in distal and collecting tubules when ADH is present
Normal urine osmolality is 1 to 3 times that of plasma
300 mOsm 100 mOsm 300 mOsm
Compare and contrast specific gravity and discuss their determined factors
Specific gravity
Comparison of density of urine to that of water
Normal ranges: 1.002-1.035
Above 1.04 is physiologically impossible unless excreting high-molecular-weight
substance
Depends on number of particles and mass
Fluid intake
State of hydration
, Explain the causes of extremely high gravity value of the urine specimen and how
to handle it
Higher than 1.050
Happens when urein has high-molecular-weight substance
X-ray dye
Substances are infused into patients and excreted in the urine
Consider a contaminant and don't indicate disease or disorder
New specimen should be collected latte
Explain why urea and creatinine can be used to monitor renal function
Large concentration in urine
Easy to measure
Precision and reliability of each measurement method are known and well documented
Discuss the osmolality change of the urine during its formation process. State the
effects of the ADH
Osmolarity remains unchanged (isometric at ~300 mOsm) until the filtrate reaches the
thin descending limb of the loop of Henle
Filtrate in the Loop of Henle becomes hypersomatic and when it enters the distal
tubules is 100 mOsm
Final osmolarity of urines determined in the distal tubules and collecting
When ADH is present, the filtrate is again 300 mOsm
Define polyuria, oliguria, and anuria. Discuss and differentiate their causes.
