Kidney's Part 2 Flashcards
The ability of kidneys to remove molecules from the blood plasma by excreting them in the urine
Renal clearance
How does reabsorption affect renal clearance? How does filtration affect it? And secretion?
decreases, increases, increases
What kind of molecules are elimiated in the urine more rapidly than by just glomerular filtration?
xenobiotics
Substances that are used to evaluate GFR and why?
inulin, creatinine, they are neither reabsorbed nor secreted by tubules
Drug used to treat gout
probenecid
Why is glucose not present in urine
secondary active transport in the proximal tubule, cotransport of glucose and Na+
What happens when glucose carriers are saturated?
glycosuria
What is the renal plasma threshold for glucose?
190 mg per 100 ml blood
Fasting hyperglycemia is caused by
inadequate secretion or action of insulin
How is diabetes mellitus similar to drinking seawater
osmotic diuresis
What stimulates the parathyroid hormone secretion?
fall in plasma ca2+
What secretes the hormone that regulates renal reabsorption of na+ and k+?
adrenal cortex
Where is the primary site of aldosterone action and what does it influence?
cortical collecting duct, Na+/K+ pumps
What K+ is secreted into the late distal tbule/collecting duct and why?
K+ in the diet, so blook K+ stays the same
A k+ rich meal stimulates _____ to secrete _____
adrenal cortex, aldosterone
Reabsorption of Na+ promotes what action of K+
secretion into the filtrate
What is the primary cilium and how does it influence K+?
a mechanosensor that acts as a second messenger of sorts and can activate K+ channels –> K+ secretion
How do diuretics influence sodium and potassium
inhibits transport of na+ in nephron loop and increases delivery of Na+ to distal tubule–> more reabsorption–>more secretion of potassium
What would someone taking diuretics also want to take?
potassium supplements
What can cause hyperkalemia?
hyponatremia and adrenal insuffiency (addison’s)
What causes hypokalemia?
excessive aldosterone (hyperaldosteronism or Conn’s synrome), cushing’s syndrome, diuretics
What can hypokalemia lead to
heart arrythmia, muscle weakness
How does decrease in Na+ promote aldosterone secretion
indirectly bc leads to low blood volume which activates the renin angiotensin aldosterone system
Where is the juxtaglomerular apparatus?
where the afferent arteriole comes in contact with the last portion of the thick ascending limb
