Save
Terms in this set (67)
urine formed as blood flows through the kidneys.
anatomy of the kidney and
800,000-1,000,000 nephrons in each kidney to filter and
urinary system
remove waste
kidneys serve as the primary mechanism for excreting
drug metabolites, waste products include: urea* (MUST
regulation of excretion
be excreted in urine or else it accumulates in body
tissue), Cr, phosphates, sulfates, uric acid
uric acid formed as a waste product of purine metabolism
maintain homeostasis through urine formation
(continuous filtration, secretion, reabsorb), regulation of
function of the kidneys F&E/acid-base balance, renin to regulate BP,
erythropoietin for RBC production, VitD activation,
production/release of bradykinins & prostaglandins
kidneys receive 20-25% total cardiac output, renal artery
--through renal cortex--> afferent arterioles (each
kidney blood supply branch forms glomerulus) -> efferent arteriole (blood
leaves glomerulus through here) -> flows back to
inferior vena cava
forms collection of capillaries that direct blood flow to
afferent arterioles
glomeruli of nephrons
transport blood away from glomeruli and into the peri-
efferent arteriole
tubular capillaries
susceptible to kidney injury r/t renal structural and
functional changes; sclerosis of glomerulus and renal
older adult considerations vasculature, HoTN, decreased GFR/renal reserve,
of kidney dfx altered tubal function and acid/base balance,
incomplete emptying of the bladder, urinary stasis,
decreased drug clearance
, amount of blood filtered by glomeruli in set amount of
glomerular filtration rate time, dependent on systemic BP, blood flow, and blood
volume; kidneys try to compensate for BP changes
2nd and 3rd phase of urine formation; movement of
water and solutes from tubular filtrate back into blood
tubular reabsorption and
(99% glomerular filtrate reabsorbed to avoid
secretion
dehydration), then substances move from capillaries
into renal tubule cells, then into urine to be excreted
urine must be concentrated prior to its excretion from
body, body would quickly experience dehydration w/o
urine concentration ability to concentrate urine, loop of henle has a
significant role (reabsorbs additional water, descending
portion permeable to h2o)
control composition of blood by reabsorbing/secreting
kidney regulatory function: (rate depends on serum concentration) electrolytes to
electrolyte balance maintain normal ranges, PCT responsible for 80% of
electrolyte reabsorption
maintain serum pH 7.35-7.45, kidneys reabsorb/return
bicarb body's circulation from urinary filtrate (can
kidney regulatory function:
generate new bicarb), excrete acid into urine (acid
acid-base balance
production as a result of catabolism & breakdown of
proteins)
aids in BP auto-regulation (constriction/dilation of
afferent and efferent arterioles), produced/released
kidney hormonal function:
when receptors in kidneys sense decrease in blood
renin
flow, volume, or pressure or when decreased levels of
Na in renal blood supply detected
hormone produced exclusively by the kidneys in
response to decreased renal blood flow and hypoxia,
kidneys hormonal function:
RBC production exclusive to the kidneys, stimulates
erythropoietin
bone marrow for RBC production, anemia occurs when
insufficiently produced
obtained through diet and exposure to UV radiation,
kidneys hormonal function: activated vitamin D is necessary for maintaining normal
vitamin D calcium balance in the body (required for GI Ca
absorption, lowering Ca levels with renal impairment)