44 - Problems of Urinary System Flashcards
upper urinary system
2 kidney + 2 ureters
lower urinary system
bladder + urethra
(6) kidney functions
1 reg volume + composition of ECF 2 excrete wastes 3 control BP 4 make erythropoietin 5 activate vit D 6 reg acid-base balance
kidney location
- between T12-L3
- right is lower than left
__ protects the kidneys and acts as a shock absorber
capsule
parenchyma
tissue of the kidney
functional unit of the kidney
nephron
-each kidney has 1 mil nephrons
each nephron is composed of…
- glomerulus
- bowman’s capsule
- tubular system
amount of blood flow to kidneys
1200 mL/min
-accounts for 20-25% of CO
glomerulus
collection of up to 50 capillaries
-where urine formation begins + where blood is filtered
filtration is more RAPID than ordinary tissue capillaries becasue ____
glomerular membrane is porous
formula to decide the average amount of urine output
0.5-1.5/mL/kg/hr
UOP
glomerular filtration rate [GFR]
amount of blood filtered each minute by the glomeruli
average GFR
125 mL/min
the peritubular capillary network ________ before it reaches the collecting duct
REABSORBS MOST of the glomerular filtrate
average rate of filtrate is excreted
1 mL/min
REABSORPTION is the passage of a substance from the ______ to the _____
fr the lumen of tubules
to the tubule cells + capillaries
SECRETION is the passage of a substance from the ______ to the _____
fr the capillaries
to the lumen of the tubules
proximal tubule
reabsorbs 80% of electrolytes
-inc glucose, amino acids, HCO3-, water
loop of henle
[ascending + descending]
concentration of filtrate
ASCENDING: reabsorbs Cl- > Na+
DESCENDING: reabsorption of water
distal tubule
- reabsorption of water (reg by ADH)
- reabsorp HCO3-
collecting duct
reabsorption of water
-MUST HAVE ADH
distal tubule is regulated by
ADH
-makes the distal convoluted tubules + collecting ducts MORE PERMEABLE TO WATER
2 important functions of the distal convoluted tubules
1 final regulation of water balance
2 acid base balance
25% of Na+ is reabsorbed in the ____
ascending limb of loop of henle
-passive move, follows Cl-
how is ADH secretion inhibited?
osmoreceptors in hypothalamus direct DECR plasma osmolarity
- supraoptic cells send messages to POST PITUITARY GLAND
- inhibit ADH secretion
-tubules become impermeable to water
Aldosterone
- released fr adrenal cortex
- acts on distal tubule
- reabsorbs Na+ + water
- secretion of K+
HCO3-
- reabsorbs + conserves HCO3
- secretes excess H+
Atrial Natriuretic Peptide
- released by myocyte cells in rt atrium
- triggered by atrial distention/incr plasma vol
- incr Na sodium
- inhibits renin, ADH, + ANG II
parathyroid hormone [PTH]
- released in response to LOW Ca
- incr in tubular reabsorp of Ca+
- decr reabsorp of PO4 (phosphate)
major effect on bone metabolism
vitamin D
- obtained by diet or UV radiation
- activated by liver then kidneys
- essential for absorption of Ca in GI tract
erythropoietin
- secreted by kidneys in response to HYPOXIA + DECR RENAL BF
- stims RBC production in bone marrow
renin
- secreted by juxtaglomerular cells
- activates ANGIOTENSINOGEN into ANGIOTENSIN I
- INCREASES BP
renin is released in response to ___
- decr renal perfusion
- decr arterial BP
- decr ECF
- decr serum Na
- incr urinary Na
angiotensinogen
plasma PROTEIN - not hormone
- fr liver
- activated into ANG I by renin
ACE is found in _____
inner surface of all blood vessels
-esp high in vessels of lungs
RAAS causes…
Na + water reabsorption>
incr in ECF>
incr in BP
ANG II
causes vasoconstriction >
incr BP
prostaglandin that are synth in the kidneys
- occurs primarily in medulla
- causes vasodilation > incr renal BF > promote Na excretion
- vasodilation> decr BP
____ + ____ are often sites of obstructions
ureteropelvvic junction [upj] + ureterovesical junctions [uvj]
bc ureter lumens are the narrowest at these junctions
renal colic
acute, severe flank pain
-may be caused by passing stone
renal pelvis only holds _____ of urine
3-5 mL
-kidney damage can result fr backflow of more than that amount
what happens when bladder pressure rises i.e. during voiding or coughing
muscle fibers that the ureters shares w bladder base CONTRACT FIRST
- promotes lumen closure
- next BLADDER CONTRACTS against base
- ensures UVJ closure + prevention of reflux
normal daily adult urine output
1500 mL/day
-typically 5-6x during the day
vol of urine at night is less than half formed during the day bc of ___
ADH
on average, ____ mL of urine cause moderate distention + urge to urinate
200-250 mL
-when it reaches 400-600 mL, it feels uncomfortable
urothelium
- transitional cell epithelium bladder
- resistant to absorption of urine
- —once urine has left the kidney, they cannot be reabsorbed by the urinary sistem
continence
voluntary control
if you cannot void at a given time _____ are stimulated and transmitted back to cause _______
inhibitor impulses in brain
detrusor muscles to accommodate pressure (do not contract), pshincter + pelvic floor tighten (contract)
changes in the aging kidney
30-90yr: 20-30% decr in size + weight
70’s: 50% of glomeruli have lost their function
- decr renal BF > decr GFR
- changes in hormone
women: loss of elasticity + muscle strength
men: prostate enlargement
anuria
<100 mL/daily
oliguria
100-400 mL daily
positions to help urinate
CREDES: pressing on lower ab
VALSALVA: straining
how does sedentary lifestyle affect urinary
- more likely to have stasis of urine
- demineralization of bones> incr Ca> stones
can you palpate the urinary bladder?
normally no unless distended
should kidney punch (percussion) elicit pain?
not in normal kidneys
a bladder does not percuss until it contains ___
150mL
patients undergoing diagnostic studies should not receive _______________
magnesium citrate (anything w Mg),
fleet enema,
iodine based contrast
when a patient w kidney failure has multiple diagnostic studies, it is important to make the patient stays ____
HYDRATED
urinalysis is best obtained in the ___ and best examined within ____
morning
w/in 1 hr
creatinine
waste product made by muscle breakdown
-urinary excretion of creatinine is a measure of the amount of active muscle tissue in the body
normal creatinine ranges
MALE: 107-139 mL/min/1.73cm
FEMALE: 87-107 mL/min/1.73cm
most accurate indicator of kidney function
creatinine clearance
- almost all creatinine is excreted by the kidneys
- reflection of GFR
anuria is a sign of
AKI, ESRD, bilateral ureteral obstructn
burning urine is a sign of
urethral irritation, UTI, calculus
dysuria is a sign of
UTI, interstl cystitis, calculus, + more
enuresis
involuntary nocturnal urination
enuresis is a sign of
lower urinary tract disorder
frequency is a sign of
acute inflamed bladder, retention w overflow, calculus
hematuria is a sign of
cancer, blood dyscrasias, kidney diseases, stones, UTI, anticoag
hesitancy is a sign of
partial obstruction, BPH
incontinence is a sign of
neurogenic bladder, bladder infection, injury to external sphincter
nocturia is a sign of
impaired concentrating ability, obstruction, HF, diabetes, post renal transplant, excess evening fluid intake
oliguria is a sign of
severe dehydration, shock, transfusion rxn, kidney disease, ESRD
