Water and Ion Physiology II

Question 1

Regional Specialization in the Nephron

Answer 1

In the nephron different solutes are absorbed at different times/ locations

Question 2

Where does mass absorption of water occur

Answer 2

Mass absorption of water occurs in the proximal tubule due to the high apical surface area

Question 3

Selective reabsorption occurs where in the nephron

Answer 3

In the distal tubule due to its fewer number of mito and impermeable tight junctions

Question 4

Regulation of ion and water excretion

Answer 4

Occurs in the loop of Henle, distal tubule and the collecting duct

Question 5

medullary Osmotic Gradient

Answer 5

This is a key function of the nephron as it allows form the remaining water to be extracted after the proximal convoluted tubule

is possible due to the fact that the tubule is only permeable to water and ions are only pumped out of the tubule

Question 6

What the the medullary osmotic gradient allow for?

Answer 6

it allows for reabsorptions of water from the collecting ducts by osmosis

Question 7

What does ADH do

Answer 7

Binds to its receptor which initiates the movement of vesicles which contain AQP2 to apical membrane which regulates water permeability

Question 8

the regulation of water is what type of feedback?

Answer 8

Negative

Question 9

regulation of water excretion pathway

Answer 9

1. Osmolarity of extracellular fluid
2. Osmoreceptors detect and respond
3. activity of neurosecretory cells of hypothalamus
4. ADH secretion
   5.Water reabsorption
5. water excrecton
6. conservation of water in the body which results in the negative feedback which begins the cycle again

Question 10

Sodium excretion is driven by what

Answer 10

Na/K ATPase in the basolateral membrane

Question 11

what regulates sodium excretion

Answer 11

The renin- angiotensin-aldosterone system

Question 12

How does Aldosterone aid in sodium excretion

Answer 12

stimulates the synthesis and insertion of Na/K ATPase into the Basolateral membrane thus opening the Na and K channels in the distal tubule and collecting duct increasing Na reabsorption

Question 13

how do the renal and respiratory system manage Acid and base concentration

Answer 13

Renal system slowly reabsorbs H and HCO3

the respiratory system changes breathing to monitor CO2 expiration

Question 14

Respiratory Acidosis or Hypoventilation results in what

Answer 14

a buildup of H which causes the kidneys to accumulates more HCO3 and excretes accumulated H restoring blood pH

Question 15

Respiratory Alkalosis or hyperventilation

Answer 15

when excretion CO2 excides production, in response the kinds will excrete more HCO3

Question 16

Metabolic Acidosis

Answer 16

Acid other then CO2 is added to the blood often lactic acid from extersize, in response ventilation will increase excreting CO2 thus lowering blood pH.