A & P - URINARY SYSTEM Flashcards
what does the urinary system consist of?
2 kidneys
2 ureters
1 urinary bladder
1 urethra
functions of the urinary system
-excretion of waste
-regulation of blood ions, blood pH, blood volume, blood pressure, blood glucose
-maintenance of blood osmolarity
-production of hormones
what structures make up the hilum
hilum: in cavity of renal sinus
-contains renal pelvis, calyces, branches of renal blood vessels & nerves
-blood supply: starts in hilum in renal artery off abdominal aorta
path of urinary drainage / filtrate through kidney
->nephron
->collecting duct
->papillary duct
->minor calyx
->major calyx
->renal pelvis
->ureter
->urinary bladder
->urethra
3 layers of glomerular filtration
- fenestrations
- basement membrane
- podocytes with pedicles
how much urine is held in the bladder
700-800 ml
1-2L excreted a day
what is the muscle in the bladder called?
detrusor
how long the urethra is in male & female
female: 4cm long
male: 20cm long
+ / - pressures in nephrons in terms of Bowman’s Capsule
filtration pressure:
-glomerular blood hydrostatic pressure: solutes out of blood into bowman’s capsule = promote filtration (+)
-capsular hydrostatic pressure: pressure of fluid filled capsule
-blood colloid osmotic pressure: pressure of plasma proteins pulling on water: solutes back into bloodstream = opposing filtration (-)
primary vs. secondary active transport
PRIMARY: Na+, K+ pump (Na one way, K+ the other way)
SECONDARY: anything else
-symporter: transports in SAME direction
-antiporter: transports in OPPOSITE direction
which transport uses symporters & antiporters?
SECONDARY active transport
what do you pump in the ascending loop?
Na+ - SALT
what is the renal corpuscle made of?
Glomerulus: glomerular capillaries -> where filtration takes place
Bowman’s Capsule: surrounds glomerular capillaries
what is secreted at the distal convoluted tubule? (DCT)
K+: by leakage
H+: by pumps
DYSURIA (temrinology)
painful urination
ENURESIS (terminology)
involuntary voiding
NOCTURNAL ENURESIS (terminology)
night time bed wetting (young children up to 5)
POLYURIA (terminolgy)
excessive urination
UREMIA (terminology)
toxic levels of urea in bloodstream
layers of detrusor & what they hold
- inner longitudinal: relaxed when peeing
- middle circular: form internal urethra sphincter controlled by ANS - involuntary control
- outer longitudinal: formed by skeletal muscles - voluntary control
level of spinal cord that controls micturition reflex
S2 & S3
when urinary incontinence is normal vs. when it is not
-lack of voluntary control of micturition
normal in infants up to 2-3 years old (muscles not fully developed)
path of blood supply to kidneys from abdominal aorta
->renal artery off abdominal aorta into hilum
->segmental arteries
->interlobar
->arcuate
->cortical radiate
->afferent arterioles
->glomerular capillaries
->efferent arterioles
2 types of nephrons - which dip further into medulla
-juxtamedullary nephron: 15-20% of all nephrons, deep in cortex close to medulla = LONG loop of Henle
-cortical nephron: 80-85% of all nephrons, outer portion of cortex = SHORT loop of Henle (thick segment)
what type of cells are part of the juxtaglomerular apparatus
-macula densa cells: specialized cells in ascending loop of Henle
-juxtaglomerular cells: modified smooth muscle fibers in afferent arteriole - secrete RENIN
what is unique about the ascending loop?
NO WATER - impermeable to water
too thick
GLOMERULAR FILTRATION RATE (GFR)
amount of renal filtration formed in all corpuscles of both kidneys in 1 minute
-must be stable (homeostasis)
how kidneys regulate GFR - 2 mechanisms
- by adjusting blood flow in & out
- by altering surface area
what is a podocyte with pedicle?
foot like processes that form filtration slits
-allows smaller proteins, water, vitamins
mechanisms that allow kidneys to auto-regulate without an outside influence
- Myogenic Mechanism
- Macula Densa Feedback (tubuloglomerular)
- Neuroregulation
- Hormonal Regulation
- Homeostatic Regulation
what hormones increase & decrease GFR, BP, BV
-angiotensin II: vasoconstriction - decrease GFR, increase BP
-ANP: increase GFR, decrease BV/BP
what does ADH do?
increases BV/BP
decreases urine output
what does ANP do?
decreases BV/BP
increases GFR
what does aldosterone do?
increase water reabsorption & water volume
increase BP
different roots of transport between cells
-Paracellular Reabsorption: moves substances between slightly leaky adjacent cells (passive process)
-Transcellular Reabsorption: moves substances through an individual tubule cell
kidneys - how much water is reabsorbed & where
PCT - 65%
Descending Loop - 15%
DCT - 20%
(PCT = most salty area of nephron)
what is secreted & absorbed at the PCT
ABSORBED: water, Na+, glucose, Cl-, AA, HCO3, Ca+, Mg
EXCRETED: H+, urea, creatinine, ammonium
where is urea recycled?
collecting duct
why do we get rid of urea?
to keep medulla more salty & to retain more water
what is a calyx?
papillary ducts: receives urine from minor & major calyx - then out renal pelvis & ureters
order of filtrate passing through nephron
->PCT
->Descending limb
->Ascending limb
->DCT
->Collecting duct
what does the pituitary gland secrete?
hormones - antidiuretic hormone (ADH)
DIURETICS
caffeine
alcohol
