Exam 3: Lecture 29: Renal Blood Flow, etc. Flashcards
About how much of overall cardiac output is received by the kidneys?
25%
If the overall renal blood flow increases what happens to the pressure gradient between renal artery and renal vein?
It increases
What is the major mechanism for changing renal blood flow?
Changing arteriolar resistance
What two mechanisms cause vasoconstriction of the renal arterioles?
Sympathetic nervous system and circulating catecholamines
If there is vasoconstriction on the -afferent arteriole, what happens to GFR?
It decreases
If there is vasoconstriction on the efferent arteriole, what happens to GFR?
It increases
Afferent/Efferent: which renal vessel has more alpha 1 receptors?
Afferent
Which renal vessel (afferent/efferent) is. more sensitive to angiotensin 2?
Efferent
T/F: Angiotensin 2 only affects efferent arterioles.
False - it affects both, just affects efferent more
Angiotensin 2 in _______ levels increases GFR.
Low
Angiotensin 2 in _________ levels decreases GFR.
High
If the RAAS system is activated, what would the result be on the GFR?
Decrease - the RAAS system increases the level of AG2 which causes vasoconstriction of both arterioles which decreases GFR.
Atrial natriuretic peptide causes _______ of afferent arterioles
Dilation
Atrial natriuretic peptide causes _______ of efferent arterioles.
Constriction
What is the overall effect on GFR from an increase in Atrial natriuretic peptide?
Increases
What two substances help to modulate vasoconstriction in the renal system in response to the sympathetic nervous system?
- Prostaglandins E2 and I2
- Dopamine
Renal blood flow can be maintained within what range of renal arterial pressure?
80-180mmHg