Renin Angiotensin Aldosterone System Flashcards
What is the primary function of the renin-angiotensin-aldosterone system (RAAS)?
The RAAS primarily regulates blood pressure and fluid balance.
What triggers the release of renin from the juxtaglomerular cells?
Renin is released in response to low blood pressure, low sodium concentration, and sympathetic nervous system activation.
What is the role of renin in the RAAS?
Renin cleaves angiotensinogen to form angiotensin I.
Where is angiotensinogen produced?
Angiotensinogen is produced in the liver.
How is angiotensin I formed?
Angiotensin I is formed when renin cleaves angiotensinogen.
What enzyme converts angiotensin I to angiotensin II?
Angiotensin-converting enzyme (ACE) converts angiotensin I to angiotensin II.
Where is angiotensin-converting enzyme (ACE) primarily located?
ACE is primarily located in the lungs.
What are the main actions of angiotensin II?
Angiotensin II causes vasoconstriction, stimulates aldosterone release, and increases blood pressure.
How does angiotensin II affect blood pressure?
Angiotensin II increases blood pressure by constricting blood vessels.
What effect does angiotensin II have on the adrenal cortex?
Angiotensin II stimulates the adrenal cortex to release aldosterone.
What hormone is released from the adrenal cortex in response to angiotensin II?
Aldosterone is released from the adrenal cortex.
How does aldosterone affect sodium and potassium levels?
Aldosterone increases sodium reabsorption and potassium excretion in the kidneys.
What is the effect of aldosterone on water reabsorption?
Aldosterone increases water reabsorption by promoting sodium retention.
How does the RAAS contribute to the regulation of blood volume?
The RAAS regulates blood volume by controlling sodium and water reabsorption.
What role does the RAAS play in the regulation of systemic vascular resistance?
The RAAS regulates systemic vascular resistance by causing vasoconstriction.
How does angiotensin II affect the efferent arterioles in the kidney?
Angiotensin II constricts efferent arterioles, increasing glomerular pressure.
What is the impact of angiotensin II on glomerular filtration rate (GFR)?
Angiotensin II helps maintain GFR by constricting efferent arterioles.
How does aldosterone influence acid-base balance?
Aldosterone influences acid-base balance by promoting hydrogen ion excretion.
What is the role of angiotensin II in thirst regulation?
Angiotensin II stimulates thirst in the hypothalamus.
How does angiotensin II affect antidiuretic hormone (ADH) release?
Angiotensin II promotes the release of ADH from the posterior pituitary.
What is the impact of angiotensin II on the sympathetic nervous system?
Angiotensin II increases sympathetic nervous system activity.
How does the RAAS respond to low blood pressure?
The RAAS responds to low blood pressure by increasing renin release and activating the system.
What are the stimuli for renin release from the juxtaglomerular cells?
Renin release is stimulated by low blood pressure, low sodium, and sympathetic activation.
How does renal perfusion pressure affect renin release?
Decreased renal perfusion pressure increases renin release.
What is the effect of the macula densa on renin secretion?
The macula densa detects low sodium and signals for renin release.
How does the sympathetic nervous system influence renin release?
The sympathetic nervous system stimulates renin release via beta-adrenergic receptors.
What is the role of beta-adrenergic receptors in renin secretion?
Beta-adrenergic receptors on juxtaglomerular cells promote renin release.
How do prostaglandins affect renin release?
Prostaglandins increase renin release by enhancing the signaling pathway.
What is the function of the angiotensin II type 1 (AT1) receptor?
The AT1 receptor mediates most of the known actions of angiotensin II, including vasoconstriction and aldosterone release.
How does angiotensin II type 2 (AT2) receptor function differ from AT1 receptor?
The AT2 receptor generally opposes the actions of the AT1 receptor, promoting vasodilation and anti-inflammatory effects.
What role do natriuretic peptides play in relation to the RAAS?
Natriuretic peptides inhibit the RAAS by promoting natriuresis and vasodilation.
How do ACE inhibitors affect the RAAS?
ACE inhibitors block the conversion of angiotensin I to angiotensin II.
What is the mechanism of action of angiotensin II receptor blockers (ARBs)?
ARBs block the binding of angiotensin II to the AT1 receptor.
How do aldosterone antagonists work within the RAAS?
Aldosterone antagonists block the effects of aldosterone on the kidneys.
What are the effects of RAAS overactivation?
Overactivation of the RAAS can lead to hypertension, heart failure, and kidney disease.
How is the RAAS involved in heart failure?
In heart failure, the RAAS can contribute to fluid retention and increased cardiac workload.
What role does the RAAS play in chronic kidney disease (CKD)?
In CKD, the RAAS can cause further kidney damage by promoting hypertension and proteinuria.
How does RAAS blockade benefit patients with hypertension?
RAAS blockade helps reduce blood pressure and protect organs in hypertensive patients.
What is the relationship between RAAS and hypertension?
The RAAS increases blood pressure through vasoconstriction and fluid retention.
How does the RAAS contribute to the pathophysiology of diabetic nephropathy?
The RAAS contributes to diabetic nephropathy by promoting glomerular hypertension and fibrosis.
What is the effect of angiotensin II on inflammation and fibrosis?
Angiotensin II promotes inflammation and fibrosis in various tissues.
How does angiotensin II promote cardiovascular remodeling?
Angiotensin II promotes cardiovascular remodeling by increasing smooth muscle proliferation and fibrosis.
What are the systemic effects of angiotensin II beyond blood pressure regulation?
Systemically, angiotensin II affects vascular tone, electrolyte balance, and cell growth.
How does aldosterone contribute to cardiovascular disease?
Aldosterone contributes to cardiovascular disease by promoting fibrosis and endothelial dysfunction.
What are the feedback mechanisms that regulate the RAAS?
Feedback mechanisms include the response of renin release to blood pressure, blood volume, and sodium concentration.
How does plasma sodium concentration influence renin release?
Low plasma sodium concentration stimulates renin release.
What is the impact of the RAAS on potassium homeostasis?
The RAAS helps maintain potassium homeostasis through aldosterone-mediated excretion.
How does the RAAS interact with other hormonal systems, like the ADH system?
The RAAS interacts with the ADH system to regulate blood pressure and fluid balance.
What is the clinical significance of measuring plasma renin activity (PRA)?
Measuring PRA helps diagnose disorders related to blood pressure and fluid balance.
How is the RAAS involved in the body’s response to hemorrhage?
During hemorrhage, the RAAS is activated to conserve fluids and maintain blood pressure.
