what is the function of the urinary system?
it removes waste from your blood in the form of urine
what is the function of kidneys?m
regulates blood ionic composition
blood pH
blood volume
what structures make up the urinary system?
kidneys
renal pelvis
ureters
bladder
urethra
what is a nephron?
a functional unit that consists of the renal corpuscle and real tubule
What are the 2 nephrons?
cortical and juxtamedullary
what are the basic process used by kidneys?
filtration and reabsorption
filtration
uses nephron to filtrate
reabsorption
movement of water and solutes from tubule back to plasma
secretion
water and hydrogen ions pass from the capillaries into the renal tubule
what are the 3 basic functions performed by nephrons?
filtration
reabsorption
secretion
what is the filtration membrane and factors that promote it
glomerular and blood pressure/volume
what are factors that control glomerular filtration?
capillary hydrostatic pressure
Bowmans space oncotic pressure
what is the equation for net filtration?
NFP= GBHP-CHP-BCOP
list 3 types of regulation for GFP
renal autoregulation
neural regulation
hormonal regulation
route for tubular reabsorption
solutes are reabsorbed across the wall of nephron into interstitial fluid
route for tubular secretin
solutes are secreted across the wall of nephron into the filtrate
tubular reabsorption mechanism
osmosis
tubular secretion
active transport and passive diffusion
paracellular
passive fluid leakage between cells
transcellular
directly through the tubule cells
primary active transport
uses ATP like Na and K pump
secondary active transport
driven by ions electrochemical gradient
obligatory water reabsorption
90% water follows the solutes that are reabsorbed
facultative water reabsorption
10% regulated by ADH
what happens during reabsorption in PCT?
water and solutes within PCT are transported into the blood stream causing it to be isomotic
symporters
move substances in same direction
antiporters
move substances in opposite direction
what is a nephron loop ?
something that conserves water for the organism and produces highly concentrated urine
DCT duct
short tubule that regulate extracellular fluid volume and electrolyte homeostasis
collecting duct
collects urine through it to the pelvis through ureters
principal cells
reabsorb Na and secretes K
intercalated cells
reabsorb HCO3 and secretes H
what is the homeostatic regulation of tubular reabsorption and secretion
ADH and aldosterone
5 hormones that affect the extent of Na, Cl, Ca2, and H2o
angiotensin II
ADH
aldosterone
ANP
PTH
dilute urine
osmolarity in the tubule
concentrated urine
osmotic gradient is created
how does ADH affect urine concentration?
high ADH causes concentrated urine and low causes diluted urine
countercurrent exchange
energy is used to create an osmotic gradient that enables reabsorption of water
how does female and male urethras differ?
female is short and male is long
how could kidney functions be evaluated?
blood urea nitrogen
plasma creatine
renal plasma clearance
characters of urine?
pale yellow
odorless
pH of 4.5-8.0
affects of kidneys with agin
shrunken kidneys
filtering less blood
decreased blood flow