Renal System Pt. 1 Flashcards
(50 cards)
Production of _____ in response to decreased renal blood flow and increased sympathetic discharge (___ effect)
Renin; B1
Why does chronic renal disease lead to hypocalcemia?
Kidneys responsible for activating vitamin D. Vitamin D is required for Ca absorption from the gut
Zone most vulnerable to ischemia secondary to hypotension
Inner strip of outer zone (of medulla)
What secretes renin?
Juxta glomelular cells
JG apparatus = ___ (Na sensor) + ____ ; this is important in ______
Macula densa + JG cells; volume regulation
Renal blood flow is ___ of cardiac output; ____ ml/min
25%; 1250
Components of Nephron:
Glomerulus
Afferent & efferent arterioles
Renal tubules
Site of bulk reabsorption, NOT under hormonal control
Proximal tubule
Establishes the osmotic gradient in medulla which is important in regulation of water
“Counter current multiplier”
Loop of Henle
Make final adjustments on urine pH, osmolarity, based on need. The reabsorption here IS under homronal control (aldosterone, ADH)
Distal tubule & collecting duct
85% of total
Located in renal cortex
Have short loop of henle
Cortical nephrons
Located close to renal medulla
Have long loop of henle which goes deep into medulla
Important in countercurrent system by which kidneys concentrate urine
Juxtamedullary nephrons
Remove water and other solutes from renal tubules also known as ______
Reabsorption. Peritubular capillaries
Excretion is the sum of what 3 processes?
Filtration, reabsorption, & secretion
Glomerular filtration results production of ____ L of glomerular fluid each day, out of which ____ L gets reabsorbed
180; 179
Filtration is under pressure
Ultrafiltration
Normal GFR = ?
125 ml/min
Factors governing filtration rate at the the capillary bed are:
- Net filtration pressure
- Total surface area available for filtration
- Filtration membrane permeability
GFR is directly proportional to ______
Net filtration pressure (NFP)
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 wastes that are normally disposed of
How do ACE inhibitors affect GFR?
Decrease GFR by dilating efferent arterioles —> renal insufficiency. Avoid in bilateral renal artery stenosis
The plasma conc at wchich glucose first appears in the urine (____ mg/dL)
Threshold; 250
If glucose does not reabsorb in the ___, it is ____
Proximal tubule; excreted
