Chapter 26: Urinary System Flashcards
site of blood filtration and urine production
kidneys
_______ carries urine from kidneys to bladder
ureters
what organ stores urine and squeezes it out during micturition (urination)
bladder
urethra
transports urine during urination
what is urine
filtered blood
3 key functions of the urinary system
excretion of waste production (urea, creatine, uric acid)
elimination as urine
homeostatic regulation of blood
why don’t we “pee dust”?
obligatory water loss, why we still pee when dehydrated
other functions of urinary system?
maintains pH
BP regulation
RBC prod.
Vitamin D. prod.
nephron is…
the functional unit of the kidneys
glomerulus + glomerulus capsule makes…
renal corpuscle
glomerulus (renal corpuscle)
filters 50 gal of filtrate a day into the glomerulus capsule
nephron also…
reabsorbs good that was filtered out (only SMALL things)
secrets waste products
proximal convoluted tubules
part of nephron
reabsorb 70% of water from filtrate
reabsorbs almost 100% of glucose, vitamins, etc
nephron loop
further absorbs water
helps create concentrated urine (juxtamedullary nephron)
distal convoluted tubule
part of nephron
secretes waste products
collecting duct
part of nephron
determines final concentration of urine (under control of ADH)
site of urine production
nephron
what are cortical nephrons?
most numerous (85%)
SHORT nephron loops
responsible for most reabsorption and secretion
what are juxtamedullary nephrons?
15%
more important
responsible for urine concentration
how much blood do kidneys receive a minute
1200 mL
how many gallons of filtrate do kidneys produce a day?
50 gal
flow of urine out of kidneys
renal papilla –> minor calyx –> major calyx –> renal pelvis –> ureter
urters
smooth muscle contractions carry urine to bladder
what has slit-like openings that function like valves>
urters
3 layers of smooth muscle and rugae
bladder
trigone
funnel made by 2 ureteral openings and urethra
internal urethral sphincter
involuntary smooth muscle
external urethral sphincter
voluntary skeletal muscle