BIO 2A03 RENAL SYSTEM EXAM
QUESTIONS AND ANSWERS 2026
VERIFIED.
What must kidneys do? - ANS 1. Maintain osmotic balance: determine the voluem of
urine production/water balance.
2. Regulate ion balance: extraceullar fluid osmolarity contorls loss of ions that have important
roles.
3. Mainain pH balance: by retaining or excretion H+ and HCO3-
4. Remove waste: of metabolic nitrogenous wastes and water soluble toxins
5. Respond to changing inputs: diet and hydrations
Main function of the kidneys? - ANS 1. Filtration: filters blood
2. Reabsorption: of molecules from the filtrate
3. Secretion: of specific molecules back into filtrate
4. Excretion: of urine from the body
Where are the kidneys located? - ANS posterior abdominal wall and on top of the adrenal
gland
Why are kidney tubules and their blood vessels large? - ANS They need to filter
1
,What is the macroscopic anatomy of the mammalian kidney? - ANS Two layers: outer
cortex and the inner medulla
- there are cortex pyramids which have NEPHRONS embedded in and expand into the medulla
What is a nephron? - ANS The smallest functional unit of the kidney
- individuals tubular structure that produces urine
- 100,000 of nephrons in each renal pyramid (several pyramids per kidney)
- it plays a role in urine production and collect urine in minor calyx
- main portion of the the nephron is the glomerulus which is where blood supply enters in and
out (the first step of filtration)
What is the glomerulus? - ANS Ball of capillaries in the nephron that performers the first
step of filtering blood
How is urine produced and how does it leave the kidneys? - ANS Produced: collected by
minor calyces (joins together to make a major calyx)
Leaves: leave the kidneys through the ureter and passes into the urinary bladder for storage
-leave the animal though the urethra
What are the three main transport process in the nephron? - ANS 1. Glomerular filtration:
blood goes from the glomerulus into the nephron
2. Tubular reabsorption: filtrate from the nephron to the rest of the body via peritubular
capillaries
3. Tubular secretion: from peritubular capillaries to nephron space
Glomerular filtration - ANS Blood passes from glomerulus INTO nephron
2
, Tubular reabsorption - ANS The tissues re absorb what is in the nephron
- nephron to the rest of the body through the peritubular capillaries
Tubular secretion - ANS Tissues secrete blood from peritubular capillaries into the
nephron space
What is the structure of the nephron? - ANS Exists mainly within the renal correct or
writhing the renal medulla
- cortical nephrons: 85% of our nephrons, short loops of henle (perform most of the resorptive
and secretory functions of the kidney)
- juxtamedullary nephron: 15% of our nephrons, long oops of henle (important in producing
concentrated urine, since the long loops give more opportunity for absorption)
Nephron flow of fluid ** - ANS 1. Renal corpuscle: production of filtrate (where filtration
happens, blood from glomerulus enters nephron)
- as it goes through, reabsorption of solutes
2. Proximal convoluted tubule: reabsorption of water, ions, and all organic nutrients
3. Goes to the descending limb (thick to thin): water is reabsorbed
4. Goes to ascending limb (thin to thick): sodium and chloride are reabsorbed
5. Goes to distal convoluted tubule: secretion of ions, acids, drugs, and toxins. Variable
reabsorption of water, sodium ions and calcium ions (under hormonal control)
6. Goes to collecting system: variable reabsorption of water and reabsorption OR secretion of
sodium, potassium, hydrogen, and bicarbonate ions
7. Goes through papillary duct: delivery of urine to minor calyx (water can move out into the
surrounding tissues in this step)
3
QUESTIONS AND ANSWERS 2026
VERIFIED.
What must kidneys do? - ANS 1. Maintain osmotic balance: determine the voluem of
urine production/water balance.
2. Regulate ion balance: extraceullar fluid osmolarity contorls loss of ions that have important
roles.
3. Mainain pH balance: by retaining or excretion H+ and HCO3-
4. Remove waste: of metabolic nitrogenous wastes and water soluble toxins
5. Respond to changing inputs: diet and hydrations
Main function of the kidneys? - ANS 1. Filtration: filters blood
2. Reabsorption: of molecules from the filtrate
3. Secretion: of specific molecules back into filtrate
4. Excretion: of urine from the body
Where are the kidneys located? - ANS posterior abdominal wall and on top of the adrenal
gland
Why are kidney tubules and their blood vessels large? - ANS They need to filter
1
,What is the macroscopic anatomy of the mammalian kidney? - ANS Two layers: outer
cortex and the inner medulla
- there are cortex pyramids which have NEPHRONS embedded in and expand into the medulla
What is a nephron? - ANS The smallest functional unit of the kidney
- individuals tubular structure that produces urine
- 100,000 of nephrons in each renal pyramid (several pyramids per kidney)
- it plays a role in urine production and collect urine in minor calyx
- main portion of the the nephron is the glomerulus which is where blood supply enters in and
out (the first step of filtration)
What is the glomerulus? - ANS Ball of capillaries in the nephron that performers the first
step of filtering blood
How is urine produced and how does it leave the kidneys? - ANS Produced: collected by
minor calyces (joins together to make a major calyx)
Leaves: leave the kidneys through the ureter and passes into the urinary bladder for storage
-leave the animal though the urethra
What are the three main transport process in the nephron? - ANS 1. Glomerular filtration:
blood goes from the glomerulus into the nephron
2. Tubular reabsorption: filtrate from the nephron to the rest of the body via peritubular
capillaries
3. Tubular secretion: from peritubular capillaries to nephron space
Glomerular filtration - ANS Blood passes from glomerulus INTO nephron
2
, Tubular reabsorption - ANS The tissues re absorb what is in the nephron
- nephron to the rest of the body through the peritubular capillaries
Tubular secretion - ANS Tissues secrete blood from peritubular capillaries into the
nephron space
What is the structure of the nephron? - ANS Exists mainly within the renal correct or
writhing the renal medulla
- cortical nephrons: 85% of our nephrons, short loops of henle (perform most of the resorptive
and secretory functions of the kidney)
- juxtamedullary nephron: 15% of our nephrons, long oops of henle (important in producing
concentrated urine, since the long loops give more opportunity for absorption)
Nephron flow of fluid ** - ANS 1. Renal corpuscle: production of filtrate (where filtration
happens, blood from glomerulus enters nephron)
- as it goes through, reabsorption of solutes
2. Proximal convoluted tubule: reabsorption of water, ions, and all organic nutrients
3. Goes to the descending limb (thick to thin): water is reabsorbed
4. Goes to ascending limb (thin to thick): sodium and chloride are reabsorbed
5. Goes to distal convoluted tubule: secretion of ions, acids, drugs, and toxins. Variable
reabsorption of water, sodium ions and calcium ions (under hormonal control)
6. Goes to collecting system: variable reabsorption of water and reabsorption OR secretion of
sodium, potassium, hydrogen, and bicarbonate ions
7. Goes through papillary duct: delivery of urine to minor calyx (water can move out into the
surrounding tissues in this step)
3
