blood-fluid volume control Flashcards
what is the macula densa sensitive to
sodium concentration (when it detects decreased sodium, it interprets as decreased BP)
what cells release renin into the blood
juxtaglomerular cells
what does renin combine with
angiotensinogen (from liver) to make angiotensin I
where does angiotensin I go to become angiotensin II
Lung
T/F Angiotensin II is the most powerful vasoconstrictor
T
what does angiotensin II have the greatest effect on
Efferent arteriole, causing vasoconstriction
what is the effect of angiotensin II on the adrenal cortex
(zona glomerulosa) secretes aldosterone with affects distal convoluted tubules, saving sodium and excreting potassium.
what happens when sodium levels rise in blood?
they are picked up by the osmoreceptors of the supraoptic nucleus of the hypothalamus which causes the release of ADH/vasopressin
what does ADH do to the collecting ducts
makes them permeable to water
what happens as water becomes permeable to the collecting ducts
picked up by oncotic pressure of peritubuluar capillaries and returned to blood. the water dilutes the sodium concentration, shutting off ADH. thus blood-fluid-volume control.
Flow of urine to bladder
in absence of ADH, urine is made. Collecting ducts>papilla>renal pyramids>minor calyx> major calyx>renal sinus >renal pelvis >ureters>bladder
flow of urine from bladder out (male)
prostatic urethra>membranous urethra> spongy urethra >penile urethra
what muscle voids the bladder
detruser
