17 Flashcards
urinary system func
- Filter the blood
- Get rid of toxic metabolic
wastes – nitrogenous wastes - Urea formation
- Liver converts ammonia to
urea - Regulate water, electrolyte
and acid-base balances - Get rid of hormones and
drugs
-hormones
urea formation
- Proteins amino acids NH2
removed forms ammonia - Liver converts ammonia to
urea
clomerulus
capillary bed in nephron
glomerular capsu/le
cells around the glomerulus
podocytes
viseral layer
like little feet?
Cortical nephrons
- Close to the kidney’s
surface
Juxtamedullary
nephrons
- Close to the medulla
steps of urine production
glomerular filtration
tubular reabsorption/secretion
water conservation
Glomerular filtration
- Location: Renal corpuscle
- Fluid: Glomerular filtrate
Tubular reabsorption and
secretion
- Location: PCT, nephron
loop, DCT - Fluid: Tubular fluid
Water conservation
- Location: Collecting Duct
- Fluid: Urine
Glomerular Filtration
Membrane
1.Fenestrated
endothelial cells of
capillaries
2.Basement membrane
3.Filtration slits between
the podocytes
Blood hydrostatic
pressure (BHP)
- Blood pressure in the
glomerulus
net pressure out is hi
Capsular pressure (CP)
- Hydrostatic pressure of
glomerular filtrate
push fluid into glomerulus
Colloid osmotic pressure
(COP)
- Osmotic pull from proteins
in the blood
Tubular reabsorption
process of reclaiming
water and solutes from tubular fluid and returning them to blood
biggest site of reabsportion
pct
transcell rout reabsorption
- through cell
membrane - occurs in all tubules
- anything can use
this route (if transport
proteins are available)
paracell reabsorption
- between 2 cells
- only in PCT
- only ions or very
small molecules - passive transport
only
water movement is always
passive, will follow solutes
movement from lumn into tubular cell transportation
secondary active transport
use na/k pumps
movement out of tubular cell into isf transport
passive
The amount of solute
that renal tubules can
reabsorb is limited by
the number of transport
proteins in tubule cells’
membranes
tubular secretion trasnport is
active
occurs throughout tubules, but specific molecules are often secreted in
one region
