RAAS Flashcards
____ is the functional unit of the kidney.
Nephron
What are the five parts of the nephron?
- glomerulus
- proximal convoluted tubule (PCT),
- Loop of Henle,
- distal convoluted tubule (DCT),
- collecting ducts
This part of the renal tubule contains the juxtaglomerular apparatus (JGA)
proximal convoluted tubule
____, _____, _____ are the three cell types of the juxtaglomerular apparatus
modified cells of the DCT called macula densa
extraglomerular mesangial cells,
modified smooth muscle in the wall of the afferent arteriole called juxtaglomeular cells
These cells are modifided cells of the DCT that are part of the JGA
DCT = distal convoluted tubule
JGA = juxtaglomerular apparatus
macula densa
These cells are modified smooth muscle in the wall of the afferent arteriole that are part of the JGA
JGA = juxtaglomerular apparatus
juxtaglomerular (JG) cells
JG = juxtaglomerular
Prorenin is the zymogen form of renin. What cells in the JGA store renin?
JGA = juxtaglomerular apparatus
Juxtaglomerular (JG) cells
Angiotensinogen is the zymogen from of angiotensin I.
What enzyme catalzyes the conversion of angiotensinogen into its active form?
Renin
What are the functions of angiotensin I and angiotensin II, respectively?
Both are vasconstrictors, but angiotensin I is a much **milder ** vasconstrictor.
Angiotensin II is much more potent vasocontrictor
What is the name of the enzyme that catalyzes the conversion of angiotensin I to angiotensin II
angiotensin converting enzyme (ACE)
angiotensin converting enzyme = ACE
TRUE or FALSE: ACE is found predominantly in the lungs.
angiotensin converting enzyme = ACE
TRUE
What is the name of the enzyme responsible for the degradation of angiotensin II?
angiotensinase
TRUE or FALSE
One of the direct effecs of angiotensin II is the binding of this peptide to its Type I receptors in arterioles (and other blood vessels).
This binding to its receptor results in vasocontriction and subsequent increased total peripheral resistance (TPR) and increased blood pressure (BP).
TRUE
Angiotensin II binds to Type I receptor in arterioles and acts as a vasocontrictor, resulting in increased TPR and BP.
What is the name of the receptor angiotensin II binds to?
total peripheral resistance = TPR
blood pressure = BP
angiotensin
TRUE or FALSE
One of the direct effecs of angiotensin is the vasoconstriction of the efferent arteriole at the glomerulus.
This vasoconstriction results in increased hydrostatic pressure, which also increases the glomerular filtration rate (GFR) and filtration fraction.
glomerular filtration rate = GFR
filtration fraction = FF
TRUE
TRUE or FALSE
One of the direct effecs of angiotensin II at the PCT of the renal tubule.
Angiotensin II directly stimulates the Na+/H+ exchanger
TRUE
Angiotensin II directly stimulates the Na+/H+ exchanger of the PCT.
What happens as a result of this stimulation by angiotensin II?
Increased Na+ reabsorption into the principal cells
Increased H+ secretion into the tubular lumen
Increased bicarbonate reabsorption into the blood (plasma) –> metabolic alkalosis
Angiotensin II stimulates the release of aldosterone from the adrenal cortex.
What effect does aldosteron have in order to correct low BP?
Aldosterone increases Na+ reabsorption and subsequently water reabsorption.
Water follows salt.
Angiotensin II stimulates the release of antidiuertic hormone (ADH) from the posterior pituitary gland.
What effect does ADH have in order to correct low BP?
Antidiuretic hormone (ADH) increases membrane permeability to water via the insertion of aquaporins in the principal cells of the collecting duct.
The overall effect is increased water reabsorption
Angiotensin II targets and exerts its effects on both the blood vessels (arterioles) and the kidneys to increase blood pressure when it is low.
Which
