urinary system Flashcards
organs of urinary system
kidney, ureters, bladder, uretha
removes wastes
kidney
force urine into bladder
ureters
stores urine
bladder
urine from bladder to outside of body
uretha
functions of kidney
removes wastes, regulates RBC, blood pressure, calcium absorption, pH of blood
product of nucleic acid catabolism
uric acid (nitrogenous waste)
product of creatine phosphate catabolism
creatine (nitrogenous waste)
a by product of protein catabolism
urea (nitrogenous waste)
separating wastes from body fluids and eliminating them
excretion
C02, small amounts of other gases and water
respiratory system
water, inorganic salts, lactic acid, urea in sweat
integumentary system
water, salts, CO2, lipids, bile pigments, cholesterol, and other metabolic waste
digestive system
many metabolic wastes, toxins, drugs, hormones, salts, H+, and water
urinary system
lie against posterior abdominal wall at level of T12 to L3
kidney
which kidney is slightly lower due to large right lobe of liver
right kidney
crosses the middle of the left kidney
rib 12
kidney, uterus, urinary bladder, renal artery and vein, and adrenal glands are all what
retroperitoneal
kidney is the size of what
bar of bath soap
lateral surface is convex, and medial is concave with a split (hilum) receives renal nerves, blood vessels, lymphatics, and ureter
kidney
immediately deep to parietal peritoneum; binds it to abdominal wall, dense; anchors kidney in place
renal fascia (protective tissue covering of kidney)
cushions kidney and holds it into place
perirenal fat capsule ( protective tissue covering of kidney)
hard; encloses kidney protecting it from trauma and infection
fibrous capsule (protective tissue covering of kidney)
glandular tissue that forms urine
renal parenchyma
cavity that contains blood and lymphatic vessels, nerves, and urine-collecting structures
renal sinus
two zones of renal parenchyma
outer renal cortex and inner renal medulla
extensions of the cortex that project inward toward sinus
renal columns
6 to 10 with broad base facing cortex and renal papilla facing sinus
renal pyramids
one pyramid and its overlying cortex
lobe of kidney
cup that nestles the papilla of each pyramid; collects its urine
minor calyx
formed by convergence of 2 0r 3 more minor calyces
major calyces
formed by convergence of 2 or 3 major calyces
renal pelvis
tubular continuation of the pelvis that drains urine down to the urinary bladder
ureter
kidneys convert blood plasma to urine in 4 stages:
glomerular filtration, tubular reabsorption and secretion, and water conservation
fluid in the capsular space; similar to blood plasma except that it has almost no protein
glomerular filtrate
fluid from the proximal convoluted tubule through the distal convoluted tubule; substances have been removed or added by tubular cells
tubular fluid
fluid that enters the collecting duct, undergoes little alteration beyond this point except for changes in water content
urine
special case of capillary fluid exchange in which water and some solutes in the blood plasma pass from the capillaries of the glomerulus into the capsular space of the nephron
glomerular filtration
retroperitoneally; between dorsal body wall and parietal peritoneum
location of kidney
convex lateral surface; concave medial surface; renal hilum on concave surface
general appearance of kidney
glomerular filtration regulation is achieved by 3 __ mechanisms
homeostatic
- renal autoregulation
- sympathetic control
- hormonal control
GFG controlled by adjusting glomerular __ from moment to moment
blood pressure
nephron controls itself with myogenic mechanism and tubuloglomerular feedback
renal autoregulation
nervous system controls nephron
sympathetic control
system of hormones that helps control blood pressure and GFR; hormones control nephron
renin-angiotensin-aldosterone mechanism
substances pass through cytoplasm of PCT epithelial cells and out their base
transcellular route
substances pass through PCT cells
paracellular route
process of reclaiming water and solutes from tubular fluid and returning them to blood
tubular reabsorption
two routes of reabsorption:
transcellular route and paracellular route
reabsorbed fluid is ultimately taken up by __
peritubular capillaries
Na+ is most abundant cation in __
filtrate
negative chloride ions follow the positive sodium ions by __
electrical attraction
creatinine isnt __ -it is passed in urine
reabsorbed
kidneys reduce 180 L of glomerular filtrate to __
1 or 2 L of urine
In PCT, water is reabsorbed at constant rate called
obligatory water reabsorption
reabsorbs water and solutes that leave the basal surface of the tubular epithelium
peritubular capillaries
3 facts promote osmosis into the capillaries
high interstitial fluid, low blood hydrostatic pressure, high colloid osmotic pressure
renal tubule extracts chemicals from capillary blood and secretes them into tubular fluid
tubular secretion
secretion of varying proportions of hydrogen and bicarbonate ions helps regulate pH of body fluids
acid-base balance
urea, uric acid, bile acids, ammonia, and little creatinine are secreted into the tubule
waste removal
clearance of drugs and contaminants
morphine, penicillin, and aspirin
primary function is to generate salinity gradient that enables collecting duct to concentrate the urine and conserve water
nephron loop
two kinds of cells in the DCT and collecting duct:
principal cells and intercalated cells
most numerous cell, has receptors for hormones, involved in salt and water balance
principal cells
involved in acid-base balance by secreting H+ into tubule lumen and reabsorbing K+
intercalated cells
“salt retaining hormone”
aldosterone
runs through medulla, reabsorbs water, making urine up to four times more concentrated
collecting duct
as urine passes through the increasingly salty medulla, water leaves by osmosis, concentrating urine
collecting duct
the ability of kidney to concentrate urine depends on __
salinity gradient in renal medulla
acts as a countercurrent multiplier
nephron loop
recaptures salt and returns it to renal medulla which multiplies the osmolarity of adrenal medulla
countercurrent multiplier
examination of physical and chemical properties of urine
urinalysis
varies from clear to deep amber depending on state of hydration
appearance of urine
due to urochrome pigment from breakdown of hemoglobin (RBCs)
yellow pee
suggests a urinary tract infection, trauma, or stone
cloudiness or blood in pee
pus in the urine
pyuria
blood in urine due to urinary tract infection, trauma, or kidney stones
hematuria
bacteria degrade urea to ammonia, some foods and diseases impart particular aromas in pee
odor
compares urine samples density to that of distilled water
specific gravity
density of urine
1.001 to 1.028 g/mL
urine pH
4.5-8.2 , usually 6.0 (mildly acidic)
chemical composition of urine
95% water, 5% solutes
retroperitoneal, muscular tubes that extend from each kidney to the urinary bladder
ureters
flap of __ at entrance of each ureter acts as a valve into the bladder; keeps urine from backing up
mucosa
3 layers of ureters
adventita
muscularis
mucosa
lumen is very low in __, easily obstructed by kidney stones
ureters
muscular sac located on floor of the pelvic cavity
urinary bladder
inferior to peritoneum and posterior to pubic symphysis
urinary bladder
urinary is covered by __ and has muscularis and mucosa layers
parietal peritoneum
conspicuous wrinkles in empty bladder
rugae of urinary bladder
smooth-surfaced triangular area on bladder floor that is marked with openings of ureters and urethra
trigone
moderate fullness of urinary bladder is 500mL, maximum fullness is
700 to 800 mL
thins from five to six layers to two or three in the urinary bladder
epithelium
tube that conveys urine out of body
urethra
3 to 4 cm long, bound to anterior wall of vagina, external urethral orifice is between vaginal orifice and clitoris
female urethra
where urethra passes through pelvic floor
skeletal muscle- voluntary control
external urethral sphincter of female urethra
18 cm long, 3 regions of mens urethra:
prostatic, membranous, spongy urethra
detrusor muscle thickening
internal urethral sphincter of male
skeletal muscle of pelvic floor
external urethra sphincter of male
passes through muscular floor of pelvic cavity
membranous urethra of male
passes through muscular floor of pelvic cavity
membranous urethra of male
__ activity stimulates postganglionic fibers to the detrusor muscle (relax it) and internal urethral sphincter (excite it)
sympathetic
___ travels through pudendal nerve to supply the external sphincter to allow voluntary control
somatic motor fibers
act of urinating
micturution
involuntary spinal reflex that partly controls urination
micturition reflex
can survive with __ of a kidney
one third