urinary pt 2 Flashcards
(48 cards)
The production of urine involves:
Glomerular filtration:, Tubular reabsorption: , and Tubular secretion:
fluid filtered from the blood to the
glomerulus
Glomerular filtration:
amount of filtrate
formed in all the renal corpuscles of both kidneys each
minute.
glomerular filtration rate (GFR):
returning important substances
from the filtrate back to the body
Tubular reabsorbtion
the movement of waste materials
from the body to the filtrate.
Tubular secretion:
_____ s the formation of a protein-free
filtrate (ultrafiltrate) of plasma across the glomerular
membrane.
Glomerular filtration
main force that “pushes”
water and solutes through the filtration membrane
(promotes filtration). *Primary determinant of amount of
filtrate
Blood hydrostatic pressure
from the capsular space
(opposes filtration)
Capsular hydrostatic pressure
osmotic pressure of
plasma proteins “pulling” on water (opposes filtration)
Blood osmotic (oncotic) pressure:
Final part of the ascending limb of the loop of Henle
contacts the afferent arteriole for that _____
renal corpuscle
Columnar tubule cells in the afferent arteiole region are the
macula densa
Wall of the afferent arteriole contains
juxtaglomerular (JG)
cells: modified
smooth muscle fibers
Juxtaglomerular
apparatus (JGA):
juxtaglomerular cells
and macula densa
Regulation of the GFR
- Renal autoregulation: ____
- Neural regulation:______
- Hormonal regulation: ______
-by kidneys
- by the ANS
-by angiotensin II and atrial
natriuretic peptide (ANP)
- Stretching in the glomerular capillaries or pressure and
flow monitored in the JGA, causes - afferent arterioles to constrict (decreasing
blood flow and GFR) or dilate (increasing
blood flow and GFR) appropriately
Renal autoregulation of GFR occurs by two means:
sympathetic ANS fibers
cause vasoconstriction
Neural regulation:
Two hormones contribute to regulation of GFR
Angiotensin II, and ANP (released under high bp)
vasoconstrictor of both afferent and
efferent arterioles (reduces GFR)
Angiotensin II:
_____ causes the
glomerulus to relax,
increasing the surface
area for filtration
atrial natriuretic peptide (ANP). (released under high
bp)
is the process of returning important
substances (“good stuff”) from the filtrate back into the renal
interstitium, then into the renal blood vessels… and
ultimately back into the body.
Tubular reabsorption
The “good stuff” being reabsorbed is ________, and any small proteins that might have
inadvertently escaped from the blood into the filtrate.
glucose, electrolytes, vitamins, water,
amino acids
______ percent of the glomerular filtrate is reabsorbed
(most of it in the PCT)
99
Reabsorption into the interstitium has two routes:
Paracellular reabsorption and transcellular reabsorption
passive process between
adjacent tubule
cells
paracellular reabsorption