urinary renal system for exam 3

functions of urinary system

excretion, water and electrolyte balance, conservation of nutrients, control blood cell formation, regulate BP, produce 1 mL/min of urine

primary function of the kidneys

regulate extracelluar fluid (plasma, interstitial)

kidneys regulate:

blood volume, concentration of waste/electrolytes, plasma pH

nutrients + by-products of kidney

glucose + CO2/H2O, lipids + CO2/H2O, proteins + CHON/urea/creatinine

uremia

increase of urea and creatinine in blood, renal failure

BUN tests

blood urea nitrogen test, measures blood samples to indicate renal failure

normal renal blood urea output

15 ml/dL

peristalsis

smooth m. of ureters contracts to move fluid down tubules

why does the ureters insert into the urinary bladder posterior and inferiorly?

to fill bladder from the bottom instead of dripping down from the top

oliguria

less than 1 ml/min of urine produced

diuretics used to?

increase rate of urine production, as BP medication

kidney stones

caused by oliguria, not hydrated enough/not making enough urine so casts solidify and form stones

hydronephrosis (2 types)

unilateral and bilateral types of kidney stones

unilateral hydronephrosis

kidney stone in ureter

bilateral hydronephrosis

kidney stone in urethra *treat by surgery/drinking lots of H2O)

renal blood flow (RBF)

1 L/min (half goes to each R/L side)

how much blood flow through kidney?

20% (5 L/min of blood flow thru heart)

nephron

structural and functional unit of urine formation in the kidney, of renal corpuscle and tubules

glomerulus located in?

cortex of kidney, afferent arterioles drain into it

glomerulus

filtration site for blood and move it into nephron, has loops of fenestrated capillaries, gives granular look of cortex

renal corpuscle

site of filtration in cortex, composed of glomerulus and bowmans capsule, 180 L of fluid passes, no blood passes (only solutes and water)

rental tubules

site of reabsorption and secretion into blood, give pyramid look to the medulla; PCT, DCT

compounds in blood you need to know!

RBC, plasma proteins, water, sodium, glucose, urea, creatinine, urobilin

what stays in glomerulus/cardiovascular system out of all the compounds in the blood?

RBC and plasma proteins

nitrous waste

urea and creatinine

what compounds of the blood are reabsorbed?

water, sodium, glucose

glomerular hematuria

damage to glomerulus, RBC change shape, blood comes out in urine

non glomerular hematuria

blood from kidney stones/bladder cancer/UTI, normal RBC shape

renal damage/disease can potentially lead to?

anemia, bc you lose RBC faster than they are made

proteinuria

damage to glomerulus, plasma proteins come out of urine, can be an sx of hypertension or lead to edema

why can proteinuria lead to edema

less than 7% of plasma proteins in body = edema, bc not enough osmotic pressure to bring fluid from tissues back, so there if fluid buildup)

filter

leaving the glomerulus and entering nephron

reabsorbed

taken from tubule back into bloodstream

secreted

take from bloodstream and put into tubule after filtration occurs

excreted

substances taken from blood are put into tubules and eliminated from thebody

compounds in the blood NOT filtered

RBC and PP

compounds in the blood only filtered and reabsorbed

water, glucose, sodium

compounds in the blood that are filtered and excreted

urea, creatinine, urobilin

kidney filtration

all compounds secreted at same time, different compounds have different abilities to filter/reabsorb/excrete

glomerular filtration rate (GFR)

measure of what compounds are filtered into ultra filtrate in kidney tubules (from blood to nephron)

ultra filtrate

measures how well kidneys are working, found in tubules

normal GFR

125 mL/min or 180 L/day

amount of blood in body normally/on average

5 L

with a normal GFR, how many time is blood filtered per day?

blood filtered 35x a day (180/5)

relationship between GFR and blood flow

linear relationship

diuresis

production of more than 1 mL/min of urine

amount of L reabsorbed normally

178.5 L (total is 180 - 1.5 L of urine)

renal disease

accumulate more nitrous waste, less than 60 mL/min GFR

end stage renal disease (ESRD)

kidneys stop filtering so nitrous waste stays in the body, less than 15 mL/min GFR

treatment options for ESRD

kidney transplant, dialysis, death

water absorption occurs where?

PCT and collecting ducts respectively

PCT

first place for reabsorption, 80% of water filtered and reabsorbed back to blood, mandatory water reabsorption

collecting duct

last place of water reabsorption for remaining amounts of water, goes back into blood, facilitated water absorption (adjustable), modifiable depending on hydration bc of regulation from hypothalamus and antidiuretics

sodium glucose co-transporter (SGLT1) in PCT

Na+/glucose enters vasa recta and water follows thru osmosis, mandatory water reabsorption

mandatory water reabsorption

reabsorb Na+/glucose, water will follow solutes, in PCT it is dependent on Na and glucose presence

more hydrated means…

less reabsorption and more excretion

less hydrated means…

more reabsorption and less excretion

antidiuretic hormone (ADH)

produced in hypothalamus and released by posterior pituitary gland, allows for water reabsorption in the collecting duct, urine output decreases

V2 receptors (vasopressin) of collecting duct

on basolateral membrane of kidney tubules, lets ADH bind so vesicles move to apical membrane and aquaporins insert themselves to reabsorb water

ADH only released if…

individual is dehydrated (if hydrated, no ADH needed)

facilitated water absorption only works if…

antidiuretic hormone is present, and aquaporins only work if antidiuretic is present

diuretics treat what conditions?

hypertension and pulmonary edema: decreases blood volume and lowers BP

types of diuretic drugs

flozin, V2 antagonists, and anti-ADH

flozin

targets/antagonizes the PCT’s SGLT1, inhibits Na+/glucose/water uptake so it stays in ultra filtrate: increases water in tubules —> increase in water excreted

V2 antagonists

antagonizes V2 receptors from antidiuretics, so vesicles don’t get the signal to move = no path for water for facilitated water reabsorption

anti ADH (ethanol, caffeine)

suppresses ADH production, less facilitated water reabsorption = more excreted out, you lose more water than you’re drinking