If solution A has a higher concentration of solute particles than solution B and if these solutions are separated by a semipermeable membrane, then there will be a net movement of water
into solution B since B has a lower osmotic pressure than solution A
into solution B since B will have a higher hydrostatic pressure than solution A
into solution B since the osmolarity of B is less than that in solution A
into solution A since B has a higher osmotic pressure than solution A
into solution A since A has a lower concentration of water than solution B
What might account for a net movement of water from solution X into solution Y?
a. Solution X has a higher osmolarity than the cell.
b. Solution X has more milliosmoles of solute per liter than the cell.
c. Solution X has a higher hydrostatic pressure than solution Y
d. All of the above e. Only a and b
A substance does not move down a concentration gradient through
a. a symporter
b. an antiporter
c. a primary active transporter
d. a secondary active transporter e. facilitated diffusion carrier
Which of the following is not a function of the kidneys?
Excreting metabolic wastes
Maintaining proper plasma volume
Secreting aldosterone to regulate sodium
Maintaining proper osmolarity of body fluids
Assisting in maintaining the proper acid-base balance of the body
The peritubular capillaries
supply nutrients and O2 to the tubular cells
take up the substances that are reabsorbed by the tubules
supply substances that are secreted by the tubules
perform all of the above
perform none of the above
Which nephron structure is especially important in the kidney's ability to produce urine of varying concentration?
Bowman' capsule
proximal tubule
c. distal tubule
loop of Henle
glomerulus
The renal process whereby substances are selectively transferred from the peritubular blood into the renal tubule is
filtration
secretion
reabsorption
excretion
none of these
The glomerular filtration rate is
about 115-125 ml/min
about 70-75 liters/day
60 to 65 percent of the cardiac output
less than the rate of renal reabsorption
all of the above
The glomerular filtrate
is a protein-free plasma
is formed as a result of passive forces acting across the glomerular membrane
does not contain foreign compounds because these substances are secreted by special
transport mechanisms in the proximal tubule instead
is both a and b
is both a and c
Changes in the glomerular filtration rates are accomplished through
autoregulation
myogenic activity
vasoactive responses in the afferent arteriole
all of the above
none of the above
The macula densa
consists of specialized tubular cells in the juxtaglomerular apparatus
consists of specialized arteriolar smooth-muscle cells in the juxtaglomerular apparatus
secretes renin
has characteristics a and b
has characteristics b and c
Which of the following forces oppose glomerular filtration?
Blood colloid osmotic pressure
Bowman's capsule hydrostatic pressure
Glomerular-capillary blood pressure
Both a and b
Both b and c
Afferent arteriolar vasoconstriction ____ blood flow into the glomerulus, which causes the glomerular-capillary blood pressure to ____, leading to a(n) ____ in the net filtration pressure and a resultant ____ in the GFR.
increases; increase; increase; increase
decreases; decrease; decrease; decrease
increases; increase; decrease; decrease
decreases; decrease; increase; increase
none of these
Tubular reabsorption
refers to the movement of a substance from the peritubular capillary blood into the tubular
fluid
occurs by either active or passive transport
involves the process of transepithelial transport
has b and c characteristics
has none of the above characteristics
The proximal tubule
reabsorbs about 65 percent of the filtered water
is not the site of action of renin
is where glucose is reabsorbed
receives filtrate from Bowman's capsule
has all of the above characteristics