Where in the nephron does most solute reabsorption occur?

Proximal convoluted tubule

Approximately 80% of the energy used for active transport is devoted to the reabsorption of __________.

Sodium

What is the juxtaglomerular apparatus?

A system that regulates the rate of filtrate formation and systemic blood pressure

Which of the following substances is not normally found in filtrate?

1. water and small solutes
2. blood cells and large particles
3. ions, such as sodium and potassium
   nitrogenous waste particles, such as
   urea

Blood cells and large particles

What is the primary driving force (pressure) that produces glomerular filtration?

Hydrostatic pressure of blood (blood pressure)

Which of the following would only be found in the glomerular filtrate if the glomerular membrane were damaged?

1. protein
2. chloride
3. creatinine
4. glucose

Protein

If the osmotic pressure in the glomerular capillaries increased from 28 mm Hg to 35 mm Hg, would net filtration increase or decrease?

Net filtration would decrease

Calculate the net filtration pressure if capillary hydrostatic pressure is 60 mm Hg, capillary osmotic pressure is 25 mm Hg, and capsular hydrostatic pressure is 10 mm Hg.

25 mm Hg
60 - (25 + 10) = 25 mm Hg

Most solutes that are reabsorbed in the proximal convoluted tubule use which of the following pathways?

paracellular

OR
transcellular

Transcellular

During reabsorption of water in the proximal convoluted tubule, what causes water to diffuse from the lumen into the interstitial space?

1. a decrease in the osmolarity of the
interstitium
2. active transport of water
3. an increase in the osmolarity of the
interstitium

An increase in the osmolarity of the interstitium

The decreased intracellular concentration of sodium in tubular cells during active transport is caused by which of the following mechanisms?

1. the sodium-potassium ATPase pump in the basolateral membrane
2. the sodium-potassium ATPase pump in the luminal membrane
3. sodium-glucose cotransporter
4. passive sodium channels

The sodium-potassium ATPase pump in the basolateral membrane

The active transport of which ion out of proximal convoluted tubule cells causes the reabsorption of both water and solutes?

1. potassium
2. sodium
3. chloride

Sodium

Which of the following transporters in the luminal membrane results in secretion?

1. Na+-H+ countertransport
2. Na+-glucose cotransporter
3. potassium ion channel
4. glucose carrier transporter

Na+-H+ countertransport

What is the limiting factor for the reabsorption of most actively transported solutes in the proximal tubule?

1. number of transport carriers in the basolateral membrane
2. number of sodium-potassium ATPase pumps in the basolateral membrane
3. number of transport carriers in the luminal membrane

Number of transport carriers in the luminal membrane

Which of the following best describes glomerular filtration rate (GFR)?

1. the volume of filtrate created by the kidneys per minute
2. the volume of urine leaving the kidneys per minute
3. the volume of filtrate created at the glomerulus per liter of blood flowing through the glomerular capillaries
4. the volume of blood flowing through the glomerular capillaries per minute

The volume of filtrate created by the kidneys per minute

GFR regulation mechanisms primarily affect which of the following?

blood osmotic pressure (OPg)
capsular osmotic pressure (OPc)
glomerular hydrostatic pressure (HPg)
capsular hydrostatic pressure (HPc)

Glomerular hydrostatic pressure (HPg)

Which of the following are mechanisms of intrinsic control of glomerular filtration (renal autoregulation)?

1. myogenic mechanism and tubuloglomerular feedback
2. tubuloglomerular feedback and the renin-angiotensin mechanism
3. sympathetic nervous system control and the renin-angiotensin mechanism
4. myogenic mechanism and sympathetic nervous system control

Myogenic mechanism and tubuloglomerular feedback

Macula densa cells of the juxtaglomerular apparatus (JGA) regulate GFR through which intrinsic mechanism?

1. myogenic mechanism
2. renin-angiotensin mechanism
3. sympathetic nervous system control
4. tubuloglomerular feedback

Tubuloglomerular feedback

The myogenic mechanism of renal autoregulation primarily involves smooth muscle in which blood vessels?

1. afferent arterioles
2. systemic arterioles
3. efferent arterioles
4. glomeruli

Afferent arterioles

What does a high concentration of NaCl in the renal tubule at the juxtaglomerular apparatus (JGA) most likely indicate?

1. insufficient NaCl reabsorption due to low GFR
2. excessive NaCl reabsorption due to low GFR
3. insufficient NaCl reabsorption due to high GFR
4. excessive NaCl reabsorption due to high GFR

Insufficient NaCl reabsorption due to high GFR

Through the tubuloglomerular feedback mechanism, how would an increase in filtrate NaCl concentration affect afferent arteriole diameter?

1. Afferent arteriole diameter would increase.
2. Afferent arteriole diameter would stay about the same.
3. Afferent arteriole diameter would decrease.

Afferent arteriole diameter would decrease.

Granular cells of the juxtaglomerular apparatus (JGA) regulate GFR through which mechanism?

1. renin-angiotensin mechanism
2. tubuloglomerular feedback mechanism
3. sympathetic nervous system controls
4. myogenic mechanism

Renin-angiotensin mechanism

Which hormone(s) is/are required for facultative water reabsorption in the collecting ducts?

ADH

A nonfasting urine sample from an individual who has previously ingested donuts and a soft drink showed the presence of sugar (glucose). Which of the following statement explains the presence of the glucose in the urine?

1. The individual exceeded the transport maximum.
2. The individual is glucose intolerant.
3. The individual has diabetes mellitus.
4. Some glucose is always present in the urine.

The individual exceeded the transport maximum

Which part of the brain controls the micturition reflex?

Pons

The __________ keeps the urethra closed when urine is not being passed from the bladder and prevents leaking between voiding.

internal urethral sphincter

Who is awesome?

1. Alex
2. Iffy
3. Terra

Terra

Since most patients with renal failure produce little or no urine, hemodialysis often involves removal of water from the blood. However, side-effects may develop if too much fluid is removed from the blood. Which of the following is NOT one of the potential side-effects?

1. dizziness
2. vasoconstriction of afferent arterioles
3. low blood pressure
4. muscle fatigue

Vasoconstriction of afferent arterioles

The frequency of cystitis in men is lower than in women because ______.

The male urethra is longer than the female urethra

Urinary incontinence may occur if a person has ______.

An overactive detrusor muscle