Renal function & renin-angiotensin Flashcards
What are the major structures of the urinary system
Kidneys
Ureters
Urinary bladder
Urethra
What are the kidneys responsible for
Processing blood and sifting out waste products and water
Where does the lymph drain to
Lateral aortic lymph nodes
Where is the cortical nephron located
In the cortex
Where is the juxtamedullary nephron located
Runs through the medulla
What does the cortical nephron do
Performs most reabsorptive and secretory functions of the kidney
What does the juxamedullary nephron do
Concentrate urine
Where is the bowman’s capsule located
In the cortex and encloses the glomerulus
What does net filtration pressure depend on
Glomerular blood hydrostatic pressure
Capsular hydrostatic pressure
Blood colloid osmotic pressure
How is GFR control achieved
Renal autoregulation
Sympathetic control
Hormonal control
What mechanism are used to maintain renal autoregulation
Myogenic and tubuloglomerular mechanisms
What happens if GFR is too high
Needed substances cannot be reabsorbed quickly enough and are lost in the urine
What happens if GFR is too low
Everything is reabsorbed, including waste
What are the 3 processes in the composition of urine
Filtration
Reabsorption
Secretion
What is renal function used to determine
Total % of kidney function
What is GFR
Volume of fluid filtered from glomeruli into bowman’s space per unit time
What can the assessment of GFR be carried out using
Creatinine
Inulin
Single shot technique
What is inulin
Fructose polysaccharide that is freely filtered by glomerulus
What is an advantage and disadvantage of the single shot technique
+ urine not needed, good for young patients
- using radioactive material
How is the renin-angiotensin system activated
Sympathetic stimulation
Renal artery hypotension
Decreased sodium to distal tubule
What is renin released as
Porenin (inactive) from the juxtaglomerular apparatus then converted to active renin by the kidneys
What converts angiotensin I to II
ACE
What does angiotensin II do on peripheral vasculature
Increase vascular resistance and blood pressure
What are the effects of angiotensin II on the renal system
Stimulates aldosterone release
Stimulates reabsorption of Na and water at proximal convoluted tubule
What are the effects of angiotensin II on the CNS
Stimulate release of ADH which stimulates reabsorption of water in the DCT
What are the effects of angiotensin II on the adrenal glands
Secretion of aldosterone by adrenal cortex, stimulating Na reabsorption in the DCT
Which drugs interact with the renin-angiotensin system
ACE inhibitors
ATII receptor antagonists
What are the side effects of ACE inhibitors
Hypotension
Cough
Hyperkalemia
Hyperenineamia
Angiodema
How do ATII receptor antagonists work
Blocks ability of angiotensin II to stimulate pressor effects
What are side effects of ATII receptor antagonists
Dizziness
Hyperkalemia
Angioedema
