kidney anatomy and function (midterm 3) Flashcards
what do the kidneys do
act to rid the body of waste and control the volume and composition of bodily fluids
where do substances in kidney come from/go
cleared substances are excreted in the urine, needed substances are returned in the blood
where do the kidneys lie in the body
posterior wall of the abdomen outside the peritoneal cavity
what does the medial side of the kidneys contain
an indented region (hilum), which allows passage of structure such as
- renal artery
- ureter (carriers urine out of the kidney to the bladder
what are the two regions of the kidney
the outer cortex (outside surface)
inner medulla (inside surface)
how much of cardiac output is blood flow to the kidneys
21%
what is the vascular nomenclature of the kidneys
- Blood enters the kidney through the
renal artery, then branches to form interlobar arteries,
arcuate arteries, interlobular arterioles,
and afferent arterioles - Afferent arterioles lead to the
glomerular capillaries, which then
combine to form efferent arterioles, and
then the peritubular capillaries
what are glomerular capillaries the site of
fluid and solute filtration
what do efferent arterioles regulate?
pressure
what do peritubular capillaries do
empty into the venous system - these are the site of reabsorption
where do peritubular capillaries go into
interlobular vein, arcuate vein, interlobar vein, and renal vein
where does rapid filtration come from
high hydrophobic pressure in the glomerular capillaries
where does rapid reabsorption come from
low hydrostatic pressure in the peritubular capillaries
where does fluid flow in each nephron
fluid flows from the glomerular capillaries into Bowman’s capsule, into the proximal tubule, into the loop of Henle (consists of descending and ascending limb)
what do nephrons do
they form urine (each kidney has ~ 1 million)
how many ducts form a large duct in nephrons, and what do they become
8 to 10 cortical collecting ducts join to form a larger duct, which runs downward to become the medullary collecting duct and ultimately the collecting duct
how many large ducts are in each kidney
~ 250 large collecting ducts, each which collects from ~ 4000 nephons
what are the different types of nephrons
cortical nephrons - glomeruli located in outer cortex and possess short loops of Henle
juxtamedullary nephrons - glomeruli located deep in renal cortex and possess long loops of Henle
what is micturition
emptying of the bladder
what is urinary excretion rate determined by
filtration rate minus reabsorption rate plus secretion rate
what does the rate of substance excretion into the urine depend on
glomerular filtration, reabsorption of substances from the renal tubules into the blood, and secretion of substances from the blood into the renal tubules
where does urine formation go from/to (the process)
- filtration from glomerular capillaries -> Bowman’s capsule
- renal tubules -> peritubular capillaries
- peritubular capillaries -> renal tubules
