UR Vocab Flashcards
Glomerular filtration
glomerulus (blood) -> capsular space (filtrate)
Tubular reabsorption
renal tubule (filtrate) -> peritubular capillaries (blood)
tubular secretion
peritubular capillaries (blood) -> renal tubule (filtrate)
urinary excretion
elimination from body by combination of 3 processes
excreted = filtered + secreted - reabsorbed
principle of filtration
use pressure to move fluids/solutes through a membrane
Starling forces
- blood hydrostatic pressure (PGC)
- Filtrate Osmotic Pressure (piCS)
- filtrate hydrostatic pressure (PCS)
- blood osmotic pressure (piGC)
GC: glomerulus
CS: capsular space
Renal autoregulation (and it’s two processes)
intrinisc mechanisms in kidneys trying to keep GFR within certain tolerance despite what blood pressure is doing in rest of body (homeostasis of GFR)
- myogenic mechanism
- tubuloglomerular feedback
myogenic mechanism
stimulus: blood pressure change affecting PGC and stretch of an arteriole
response: alter contraction of smooth muscle surrounding arteriole/alter radius of arteriole
tubuloglomerular feedback
stimulus: blood pressure change affecting PGC and salt concentration delivery at macula densa cells of JGA (juxtaglomerular apparatus)
GFR - regulation
extrinsic mechanisms outside of kidneys to alter GFR
neural and/or hormonal changes
Hormonal regulation - RAAS
involves renin, angiotensin, aldosterone system (RAAS)
involves formation of angiotensin ll
angiotensin ll
-decreases GFR
-binds alpha receptors - vasoconstrict afferent arterioles
-contracts mesangial cells - decrease glomerular capillary surface area
Hormonal regulation - ANP
-altered plasma volume will alter distention (stretch) of atria
-distension controls atrial natriuretic peptide (ANP) secretin and release into blood
Atrial natriuretic peptide
-increases GFR
-binds beta 2 receptors - vasodilate afferent arterioles
-relaxes mesangial cells - increase glomerular capillary surface area
tubular reabsorption and secretion
eliminating substances: glomerular filtration and tubular secretion
retaining substances: tubular reabsorption
ask how much to retain and eliminate once filtered
tubular lumen
inner cavity of renal tubule
tubular epithelial cell
cells making up inner wall of renal tubulei
interstitial fluid
extracellular fluid surrounding renal tubule
blood vessel
peritubular capillaries
tight junction
connection point between adjacent tubular epithelial cells
pathways between lumen and peritubular capillaries
- paracellular: between epithelial cells
- transcellular: through epithelial cells
2 ways of going transcellular
must cross cell membranes
1. apical
2. basolateral
apical (transcellular)
between tubule lumen and inside tubular epithelial cell
basolateral
between inside tubular epithelial cell and interstitial fluid
renal tubule - passive transports
high to low concentration (down or with gradient)
“chemical”
-simple diffusion
-facilitated diffusion
-osmosis
“electro
brackets “: electrochemical is a combination of all of this
simple diffusion
ion moving straight through membrane
facilitated diffusion
ion needs a membrane protein (MP) to provide passage
osmosis
for water: often involves aquaporin (AP: water membrane protein)
“electro”
separation of electrical charge (charge imbalance)
-positive charge towards negative charge and vice verse
-sort of seen already with action potentials as inside cell is more negative than outside so positive cells want to go into cell
renal tubule - active transports
-at least 1 one moving low to high concentration gradient (up or against gradient)
-at least 2 ions move together (cotransport or counter transport)
-primary
-secondary
cotransport
ions move together in same direction
counter transport
ions move together in opposite direction
primary
ATP - ADP and Pi to provide direct energy to pump ions across membrane
-both ions move up gradients
secondary
movement in response to conditions created by primary
-one ion move down gradient, another move up gradient (can be more than 2 ions involved)
tubular reabsorption and secretion
-specific things move in specific parts of renal tubule
-movements processes different in specific parts of renal tubule
