Renal structure / function Flashcards
general functions of the kidney
regulation of water and electrolyte balance
removal of metabolic waste, drugs, and foreign chemicals
activation of hormones
regulation of water and electrolyte balance
regulate volume and osmolarity of the extracellular fluid (blood volume and blood pressure)
urea comes from
protein breakdown
uric acid comes from
ATP breakdown
creatinine comes form
from muscle, removed by kidneys
- measures kidney function
erythropoietin
stimulates production of RBCs in the bone marrow
activation of vitamin D3
occurs in proximal tubule cells
- involved in calcium regulation
renin –>
angiotensin I –> angiotensin II –> vasoconstriction
2 types of nephrons
juxtamedullary nephrons
superficial cortical nephrons
juxtamedullary nephrons
15%
the loop of Henle goes into the inner medulla
required to make concentrated urine
superficial cortical nephrons
85%
the loop of Henle does not go into the inner medulla
the juxtaglomerular apparatus
afferent arterioles, Bowmans capsule, and the ascending limb of loop of Henle are close together
- the close physical location allows them to interact
granular cells
release renin
- eventually increase BP through angiotensin (vasoconstriction)
macula dense cells
detect increase Na+, Cl- infiltrate, constrict afferent arteriole, decrease filtration, decrease Na+, Cl- filtered
angiotensin converting enzyme (ACE)
used to treat high blood pressure
- comes from lungs
if afferent arteriole is constricted then
decrease in filtration
if efferent arteriole is constricted then
increase in filtration
if both efferent and afferent arteriole are constricted then
decrease in renal blood flow
decrease in filtration
afferent and efferent arteriole are in
series
glomerular and peritubular capillaries are in
series
reabsorption moves from
tubule to peritubular capillary
secretion moves from
peritubular capillary to tubule
capillary endothelium
stops RBCs from leaving the blood
basement membrane
main barrier of filtration
negative charge
- hard for negatively charged solutes to pass
glomerular filtration determined how much is filtered by
capillary permeability and starling forces
what needs to be reabsorbed in glomerular filtration
glucose, Amin acids, ions (H2O)
filtration pressure =
capillary hydrostatic pressure - capillary osmotic pressure
ultrafiltration pressure =
capillary hydrostatic pressure - (capillary osmotic pressure + bowman’s capsule hydrostatic pressure)
in glomerular capillaries, capillary hydrostatic pressure is
high and stays high
capillary osmotic pressure
increases because so much H2O filtered
- plasma proteins not filtered
- increases because of build up of proteins
glomerular filtration rate (GFR)
the flow rate of filtered fluid through the kidneys
GFR =
Kf x (capillary hydrostatic pressure - (capillary osmotic pressure + bowman’s capsule hydrostatic pressure ))
increase in renal blood flow causes
increased GFR and urine
auto regulation
renal blood flow remains relatively constant despite changes in mean arterial blood pressure
- intrinsic property of the kidneys
myogenic hypothesis
increasing MAP, causes to the renal arterioles to stretch, causing vasoconstriction
collecting duct
last place composition of filtrate changes –> urine
granular cells are in the
afferent arteriole
macula dense cells are on the
ascending limb of loop of Henle
stimulus for renin release
low BP
