Urine & Body Fluid Analysis Exam 1
Questions And Answers
What are the three major processes that lead to the formation of urine 1) Filtration
2) Reabsorption
3) Secretion
Filtration Occurs in the glomerulus; renin-angiotensin-aldosterone feedback system
Reabsorption Movement from filtrate to blood; filtered renal plasma is called
"ultrafiltrate"
Secretion Movement from blood to filtrate; removes unneeded foreign waste substances
not filtered by the glomerulus; mostly occurs in distal convoluted tubule
What is the functional unit of the kidney? nephron; about 1-1.5 million present in each
kidney
Function of the glomerulus Filtration of the blood/ filtration of water and dissolved
substances from the plasma
, Urine & Body Fluid Analysis Exam 1
Questions And Answers
Function of the tubules Reabsorption of substances: glucose, NaCl, amino acids,
potassium, water, calcium, urea
Function of the Loop of Henle Recovery of water and sodium chloride from the urine
Role of Antidiuretic hormone (ADH) -secreted by pituitary gland
-regulates the reabsorption of water in the distal convoluted tubule & collected tubule
What is tubular secretion? Movement from blood to filtrate
Filtration: Renin-angiotensin-aldosterone feedback system -Maintains blood pressure of
the arterioles at a relatively constant rate by regulation of the *dilation of the afferent arteriole*
and *constriction of the efferent arteriole*
-Enzyme *renin* is produced by the juxtaglomerular apparatus
-Renin is released in response to decreased blood volume or decreased blood pressure (decreased
sodium)
, Urine & Body Fluid Analysis Exam 1
Questions And Answers
What is the area of the nephron responsible for the secretion of renin? Juxtaglomerular
apparatus
Composition of glomerular ultrafiltrate Ultrafiltrate has no cells (RBCs/WBCs) and no
proteins. In comparison, plasma also does not have cells but DOES have proteins.
Renal threshold Maximum capacity of tubules to reabsorb
Glucose has a renal threshold of: 160-180 mg/dL
Active vs. passive reabsorption Active requires energy and passive does not require
energy
Reabsorption process Movement from filtrate to blood; epithelial cells lining the proximal
tubule provide a large surface area to help reabsorb >80% of the ultrafiltrate
Which substances are reabsorbed during the reabsorption process Glucose, NaCl, amino
acids, potassium, water, calcium, urea
, Urine & Body Fluid Analysis Exam 1
Questions And Answers
Role of the kidney in ion secretion and acid-base balance H+ ions secreted, ammonium
ions secreted, sodium ions reabsorbed, bicarbonate reabsorbed/secreted
What is the countercurrent multiplier mechanism Mechanism that expends energy to
create a concentration gradient which enables water reabsorption to produce concentrated urine
Explain ADH hormone -antidiuretic hormone
-secreted by pituitary gland
-regulates the reabsorption of water in the distal convoluted tubule & collecting tubule
Summarize the process of urine formation 1. Filtration from blood into nephron
2. Reabsorption from filtrate into blood
3. Tubular secretion from blood into filtrate
4. Reabsorption of water under effects of ADH
Reference range for daily average volume of urine for adults: 1200-1500 mL/day........ but
can range from 600-2000 mL/day
Questions And Answers
What are the three major processes that lead to the formation of urine 1) Filtration
2) Reabsorption
3) Secretion
Filtration Occurs in the glomerulus; renin-angiotensin-aldosterone feedback system
Reabsorption Movement from filtrate to blood; filtered renal plasma is called
"ultrafiltrate"
Secretion Movement from blood to filtrate; removes unneeded foreign waste substances
not filtered by the glomerulus; mostly occurs in distal convoluted tubule
What is the functional unit of the kidney? nephron; about 1-1.5 million present in each
kidney
Function of the glomerulus Filtration of the blood/ filtration of water and dissolved
substances from the plasma
, Urine & Body Fluid Analysis Exam 1
Questions And Answers
Function of the tubules Reabsorption of substances: glucose, NaCl, amino acids,
potassium, water, calcium, urea
Function of the Loop of Henle Recovery of water and sodium chloride from the urine
Role of Antidiuretic hormone (ADH) -secreted by pituitary gland
-regulates the reabsorption of water in the distal convoluted tubule & collected tubule
What is tubular secretion? Movement from blood to filtrate
Filtration: Renin-angiotensin-aldosterone feedback system -Maintains blood pressure of
the arterioles at a relatively constant rate by regulation of the *dilation of the afferent arteriole*
and *constriction of the efferent arteriole*
-Enzyme *renin* is produced by the juxtaglomerular apparatus
-Renin is released in response to decreased blood volume or decreased blood pressure (decreased
sodium)
, Urine & Body Fluid Analysis Exam 1
Questions And Answers
What is the area of the nephron responsible for the secretion of renin? Juxtaglomerular
apparatus
Composition of glomerular ultrafiltrate Ultrafiltrate has no cells (RBCs/WBCs) and no
proteins. In comparison, plasma also does not have cells but DOES have proteins.
Renal threshold Maximum capacity of tubules to reabsorb
Glucose has a renal threshold of: 160-180 mg/dL
Active vs. passive reabsorption Active requires energy and passive does not require
energy
Reabsorption process Movement from filtrate to blood; epithelial cells lining the proximal
tubule provide a large surface area to help reabsorb >80% of the ultrafiltrate
Which substances are reabsorbed during the reabsorption process Glucose, NaCl, amino
acids, potassium, water, calcium, urea
, Urine & Body Fluid Analysis Exam 1
Questions And Answers
Role of the kidney in ion secretion and acid-base balance H+ ions secreted, ammonium
ions secreted, sodium ions reabsorbed, bicarbonate reabsorbed/secreted
What is the countercurrent multiplier mechanism Mechanism that expends energy to
create a concentration gradient which enables water reabsorption to produce concentrated urine
Explain ADH hormone -antidiuretic hormone
-secreted by pituitary gland
-regulates the reabsorption of water in the distal convoluted tubule & collecting tubule
Summarize the process of urine formation 1. Filtration from blood into nephron
2. Reabsorption from filtrate into blood
3. Tubular secretion from blood into filtrate
4. Reabsorption of water under effects of ADH
Reference range for daily average volume of urine for adults: 1200-1500 mL/day........ but
can range from 600-2000 mL/day
