Renal Functions: regulation of osmolality
what is normal osmolality and range
the concentration of what contributes to 90%of the extracellular fluid osmolality?
osmolality is another way of saying what?
name the 3 endocrine fxns of the kidney
Vitamin D conversion into Vit D3
blood is delivered to the glomerulus via the ______ arteriole and exits the glomerulus via the ______ arteriol
there are 2 types of nephrons: what are they
picture of 2 types of nephron
the cortical nephron has short loops of henle and glomeruli located where?
near the surface of the kidney
the juxtamedullary nephrons have LONG loop of henle and the glomeruli is where
deep in the cortex near the the cortical medullary junction
again picture of 2 nephrons
blood passes through the ______ arterioles, the _____ capillaries, the _______ arterioles, and the _______ capillaries before it drains into the venous system
the ______ arteriole branches into a caillary network that entwines the renal tubule
the ______ capillaries are the capillaries that arise from the efferent arteriole and engulf the renal tubule
the ____ _____ are the peritubular cappillaries of the loops of henle of the juxtamedullary nephrons, it constitutes a countercurrent echange system
a substance may be transported FROM the tubule TO the capillary called what
a substance may be transported FROM the tubule TO the capillary called reabsorption or FROM the capillary TO the tubule called what?
the vasa recta are hairpin-shaped capillaries of the long loops of henle of what nephron
2 parts or divisons of the kidney>
Glomeruli, proximal tubules, and distal tubules are found in what part of the kidney
the loops of henle and collecting ducts are found in what part of the kidneys
what part of the outter medulla is most vulnerable to ischemia?
the LOH is a COUNTERCURRENT MULTIPLIER which does what?
creats the osmotic gradient
the vasa recta is a COUNTERCURRENT EXCHANGER what does that mean
it maintains the osmotic gradient created by the LOH
the LOH deposits NaCl in the medullary interstitium and in doing so, produces a gradient in osmolality that increases progressively from 300 to 1200 deep in the medulla. this osmotic gradient is required for what?
making the urine concentrated or making the urine dilute
hypothalamus (paraventricular and supraoptic nuleus)
secreted into what?
what is the stimulus for release
site of action
AVP (ADH) is synthesized where in the hypothalamus?
paraventricular and supraoptic nucleus
AVP/ADH is transported in the axoplasmic fluid of the hypothalmic-hypophyseal nerves to storage sites in the nerve terminals where
what stimulate the release of AVP/ADH from the posterior pituitary
nerve action potentials
when circulating levels of AVP/ADH are HIGH, what type of urine is formed
a small volume of concentrated (0.5mL/kg/kr)
when circulating levels of AVP/ADH are LOW what is the urine like
large volumes of dilute urine
what is urine osmolality with HIGH AVP/ADH
what is urine osmolality if AVP/ADH is low
what are causes of DI? (2)
failure of AVP/ADH synthesis or release (most common)
Insensitivity of distal tubules and collecting ducts AVP/ADH (nephrogenic)
what are causes of SIADH
result of surgery
Small OATS cell carcinoma
what are the diagnostic signs of SIADH
increased urine Na+ concentration
Increased Urine osmolality
decreased PLASMA osmolality
(too much ADH pissing out Na+)
Spironolactone is a competitive aldosterone antagonist that works on the late DCT and the collecting decut (mainly collecting duct). it increases excretion of what? and promotes retention of what?
increases Na+ excretion
and promotes K+ retention
Chronic Kidney disease:
what is the best test to determine renal reserve
creatinine clearance (measures GFR)