Part II Flashcards
refers to the process that moves solutes & water out of the filtrate for the second time and returns them back in the bloodstream
TUBULAR REABSORPTION
is the result from processes like diffusion, facilitated diffusion, active transport, symport, & osmosis
TUBULAR REABSORPTION
is the movement of a substance across a membrane against a gradient
ACTIVE TRANSPORT
requires the combination of the substance to be reabsorbed with a carrier protein
ACTIVE TRANSPORT
this creates an electrochemical energy, which causes the substance to be transferred across the cell membranes back into the circulation
ACTIVE TRANSPORT
is responsible for glucose reabsorption, amino acids, & PCT salts, chloride in the ascending loop of Henle, & sodium in the DCT
ACTIVE TRANSPORT
when the active transport of a substance requires energy (e.g., the Na+ pump)
direct active transport
when the transport of one substance is coupled with the transport of another substance down a gradient (e.g., the indirect absorption of glucose with Na+ in the PCT)
indirect active transport / cotransport
is the movement of a substance along a gradient (from an area of higher concentration to one of lower concentration)
PASSIVE TRANSPORT
is driven by the gradient differences in the electrical potential or concentration of molecules on opposite sides of the membrane
PASSIVE TRANSPORT
requires no energy
PASSIVE TRANSPORT
Passive reabsorption of water occurs in all parts of the nephron, except the_________ because the walls are water impermeable.
ascending loop of Henle
- the plasma concentration at which active transport stops
renal threshold
Renal threshold for glucose:
160 to 180 mg/dL
Substances in Active transport
Glucose
Amino Acids
Salts
Sodium
Substances in Passive transport
Water
Urea
Sodium
Where does renal concentration starts
Descending and ascending loops of henle
prevents the excessive water reabsorption as the filtrate passes through the highly concentrated medulla
water-impermeable walls of the ascending loop
is the process which involves selective reabsorption, that functions to maintain the osmotic gradient of the medulla
countercurrent mechanism
the starting point of the final concentration of the filtrate (through the
water reabsorption)
distal convoluted tubule
Reabsorption is dependent on the
- osmotic gradient (medulla)
- arginine vasopressin (antidiuretic hormone [ADH])
is required for water reabsorption to happen in the collecting tubules
ADH
is a hormone synthesized in the hypothalamus & transferred via the neuronal stalk to the Posterior pituitary (neurohypophysis)
ADH
-present in the ♥
-monitor arterial BP
vascular baroreceptors
is the passage of substances from the blood in the peritubular capillaries to the tubular filtrate
Tubular Secretion
takes place throughout the nephron (like tubular reabsorption)
Tubular Secretion
is the major site of the removal of plasma protein – bound foreign nonfiltered substances (e.g., medications)
proximal convoluted tubule (PCT)
The 3 body systems required in maintaining the blood pH at a level compatible with life:
the blood-buffer system
pulmonary system
renal system
The buffering & the elimination of the excess acid formed by dietary intake & metabolism in the blood aids in the maintenance of normal blood pH which is alkaline, ranging from ________
7.35 to 7.45
the buffering capacity of the blood depends on
bicarbonate (HCO3-) ions
must be expediently returned to the blood to maintain the proper pH
bicarbonate (HCO3-) ions
secretion of these ions by the renal tubular cells into the filtrate inhibits the filtered HCO3- from being
hydrogen ions (H+)
excreted in the urine & leads to the HCO3- ions being returned to the plasma
hydrogen ions (H+)
the actual excretion of the excess of these ions is dependent on tubular secretion
hydrogen ions (H+)
the adjustment of the pH, osmolality, and electrolyte content of the urine
The primary function of the distal & collecting tubules:
is the result of the disruption of the renal secretory functions
Metabolic acidosis/renal tubular acidosis (RTA)
a condition characterized by the inability to produce an acid urine
Metabolic acidosis/renal tubular acidosis (RTA)
is the volume of plasma in milliliters that is completely cleared of a substance per unit of time
Renal clearance
the standard test utilized to measure the glomerular filtering capacity
Clearance test
measures the rate at which the kidneys are able to remove (to clear) a filterable substance from the blood
Clearance test
can help in the evaluation of glomerular filtration, tubular reabsorption, & tubular secretion & in renal blood flow determinations
Clearance test
commonly performed for GFR evaluations
Clearance test
requires the use of substances with known & strictly limited modes of renal excretion
Clearance test
was measured in the earliest glomerular filtration tests because of its presence in all urine specimens & the routinely used methods of chemical analysis are existent
Urea
are substances that replaced urea as a test substance for GFR
C = creatinine, cystatin C
R = radioisotopes
I = inulin
B = β2 microglobulin
Used to be the gold standard for measuring GFR because it has all the properties of an ideal marker.
inulin
