Why is the regulation of extracellular fluid osmolarity so important?
It strongly influences cell volume.
Most cell types are ________ permeable to water. An exception is cells of the ________, which can be either impermeable or permeable, depending upon the absence or presence of ________.
not very; distal nephron; ion channels
very; distal nephron; aquaporins
Osmoreceptors are located in the _____.
hypothalamus
Dehydration triggers a/an _____ in osmolarity and secretion of _____.
increase; ADH/vasopressin
Hyponatremia _____ the secretion of ADH/vasopressin and _____ the secretion of aldosterone.
decreases; increases
Which of the following has a direct effect to signal for renin secretion?
low blood pressure
The ion imbalance known as ________ initially leads to ________ in excitable cells.
hyperkalemia; depolarization
A decrease in fluid osmolarity may result from ingesting too much water. What mechanism exists to counteract the drinking of too much water?
salt appetite
Dehydration leads to ________ blood volume, ________ blood pressure, and ________ osmolarity.
decreased; decreased; increased
What is the most important extracellular buffer system?
bicarbonate produced from CO2
Which system helps control pH by eliminating H+ from the body?
Urinary
The ________ limb of the loop of Henle is permeable only to ________, which is reabsorbed all along the length because the fluid outside is ________ concentrated deeper in the medulla.
descending; water; more
Why do patients taking loop diuretics need to take supplemental potassium?
They inhibit the reabsorption of potassium as well as sodium in the loop of Henle.
When venous return is increased, stretch receptors in the atria of the heart are activated. This results in
inhibition of ADH secretion.