The Urinary System Flashcards
nephr/o
kidney
ren/o
kidney
cyst/o
urinary bladder
vesic/o
urinary bladder
urethr/o
urethra
ureter/o
ureter
pyel/o
renal pelvis
functions of the urinary system
filter out cellular waste/toxins/excess water from blood
produce and excrete urine
fluid/electrolyte balance
pH and bp regulation
kidneys - what/where/function
what = two bean shaped organs, each = fist size
where = posterior on abdominal wall, either side of spine, outside peritoneum
function = produce urine
ureter - what/where/function
what = tubes that carry urine from kidney to bladder
where = 3 layers, fibrous outer/smooth muscle middle/mucosa inner
function = conduct urine to the bladder via peristalsis
urinary bladder - what/where/function
what = distensible (extend/contract) muscular sac
outer - loose connective tissue (blood/lymph vessels)
middle - detrusor muscle (contract to empty - smooth muscle)
inner - transitional epithelium (expand when required)
where = posterior to pubic symphysis
function = storage of urine
urethra - what/where/function
what = muscular tube/canal, surrounded by internal and external urethral sphincter
where = extends from bladder to exterior (males only - runs within prostate gland)
function = carry urine from bladder to outside of body
function of kidneys
main = filter blood and produce urine
other = excrete waste, regulation of pH, electrolytes and fluid, produce renin
nephron structure
functional unit of the kidney, microscopic structural unit
contains tubules + loop of Henle, bowman’s capsule and glomerulus
urine formation - filtration
where - glomerulus
what - passive, non-selective process driven by pressure small molecules e.g. water, AA, glucose, urea pass through semi permeable membrane while larger molecules e.g. proteins do not
urine formation - reabsorption
where - proximal convoluted tubule
what - reabsorption of substnaces e.g. water, glucose, amino acids, salts from filtrate, passive and active depending on
concentration gradient
urine formation - tubular secretion
where - distal convoluted tubule
what - drugs/medicines secreted into tubules, ions are also secreted for pH regulation, filtrate now referred to urine
thirst response
insufficient water in body
detected by osmoreceptors in hypothalamus
thirst centre stimulated
increased thirst and increased water consumption
ADH
secreted by pituitary gland -> acts on collecting duct and distal convoluted tubule
increases permeability of collecting duct to water and therefore increases reabsorption
high water = low ADH, low water = high ADH
aldosterone
secreted by adrenal gland -> acts on distal convoluted tubule
increases reabsorption of sodium and therefore water
