Renal Part 1 Flashcards
Amazing kidneys
400 gallons passes through
50 filtered out
Kidney general functions
Blood vessels of the kidneys
constriction and dilated via?
constriction — norepi & angiotensin II
dilation — dopamine & ACh
Nephron, the function unit of the kidney
Glomerulus: filtrate production
Think that mesengial cells are like little muscles and contract
Nephron structure:
What are the two cell types in the collecting duct
P cells — principle — think about how much of a principle ion Na+ is. So they help with Na+ reabsorption
Different types of nephrons:
Which one do we have more of?
Where can the vasa recta be found?
Where can peritubular capillaries be found?
What do RMICs secrete?
Which one do we have more of? cortical
Where can the vasa recta be found?
Where can peritubular capillaries be found?
“Peritubular” is around the PCT and the DCT hence the name.
Juxtamedullary has vasa recta because this nephron is much longer and permeates into the medulla
What do RMICs secrete? prostaglandins
Juxtaglomerular apparatus
grAAnular cells are on the AAfferent arteriole — BP — release renin
macula densa cells are on the distal tubule — ion concentration — mainly Na+
Relation of nephron to whole kidney
[short answer] innvervation of the kidneys
Kidney filtration
Glomerular filtration rate
What is normal GFR?
When do problems occur?
What happens with increased BP? Decreased BP?
What adjusts to offset these BP changes?
Which ions pass through easily in terms of charge? Cannot pass through?
Which cell changes permeability?
What is normal GFR? 125ml/min
When do problems occur? when the GFR is less than that
What happens with increased BP? increased GFR
Decreased BP? decreased GFR
What adjusts to offset these BP changes? with high BP, afferent arteriole constrict, with low BP, afferent arteriole dilates
Permeability
— neutral molecules pass
— negatively charged albumin doesn’t pass because capillary wall proteins are negatively charged
— positively charged get through
— mesangial cells contract and decrease permeability
[short answer] tubuloglomerular feedback
Increased blood flow to glomerulus
GFR increases
Increased diffusion of NaCl into macula dense cells
Water follows
Cells swell
Open ion channels that let out ATP
ATP converted to adenosine
Activates adenosine receptors on mesangial and smooth muscle cells
They release Ca++ intracellular lay
Constriction of afferent arterioles and decreased glomerular permeability
Decrease GFR
Kidney structure and function recap
Processes of the nephron
— What is tubular reabsorption
— What is tubular secretion
— What does this effect
— What is tubular reabsorption: bringing substances back into the body
— What is tubular secretion: adding substances to the filtrate
— Effects: concentration and volume of urine
Sodium reabsorption
Remember: main function of the PCT is reabsorption and the main function of the DCT is secretion
THIN descending loop = water OUT of LoH
THICK ascending loop = NaCl and urea OUT of LoH
Filtrate modification: proximal tubule
Filtrate modification : loop of Henley
[short answer] counter-current multiplier mechanism
Explain the role of the vasa recta
Filtrate modification: distal tubule
Filtration modification: collecting duct
Effects of aldosterone
Remember, aldosterone is the salt retaining hormone! So we’re retaining Na+ here
H2O will follow
Diuretics
Urine formation recap: proximal tubule
Recap Loof of Henle
Recap distal tubule
Recap: distal tubule
Recap: collecting duct
Renal clearance
— What is the equation?
What if RC was < > = GFR
Renal clearance =
concentration of substance in the urine (U) x flow rate of urine formation (V)
/ concentration of substance in plasma (P)
Think about this: high clearance, greater than GFR, you’re clearing the substance from your body
Work through this renal clearance problem [short answer]
Renal clearance example 2
Renal clearance example 3
Renal clearance
Urine collection
— Where does urine go after collecting ducts? 2
— PNS effect on peristaltic contractions?
— SNS effect on peristaltic contractions?
— Amount ml in a moderately full bladder?
— Max capacity of the bladder in ml?
— Where does urine go after collecting ducts? renal pelvis then ureter
— PNS effect on peristaltic contractions? increases contractions so you can pee
— SNS effect on peristaltic contractions? decreases contractions so you don’t pee
— Amount ml in a moderately full bladder? 500ml
— Max capacity of the bladder in ml? 1000ml
Bladder
[short answer] micturition reflex
