Biology 2122 Review and Objectives – Chapter 26
Vocabulary:
 Electrolytes; nonelectrolytes; metabolic water; insensible water loss; obligatory water loss; sensible
water loss; hypoproteinemia; aldosterone; angiotensin; renin; granular cells; ANP; principal cells;
intercalated cells; alkalosis or alkalemia; acidosis or academia; alkaline reserve; amphoteric
molecules; volatile acid; metabolic fixed acid; respiratory acidiosis; respiratory alkalosis; metabolic
acidosis; metabolic alkalosis
1. Know the body water content of:
 Adult males and females
 Compare adipose, skeletal muscle water content
2. Distinguish between water compartments in the body
 ECF, ICF and IF
3. Distinguish between and give examples of electrolytes and nonelectrolytes
4. Compare the electrolyte concentrations of the ECF (plasma and IF) and ICF.
5. Know what occurs when plasma osmolality rises
 Decreased saliva; how it affects osmoreceptors
 Effect on hypothalamus and thirst center, etc.
6. Know how lowered plasma volume:
 Affects blood pressure
 Affects the JGA and granular cells in the kidney
 effects on producing renin and angiotensin II
 Effects on hypothalamic thirst center
7. If osmolality is low, that ADH is released by the posterior pituitary
 How it affects water reabsorption in the kidneys
8. Know where the osmoreceptors are located
9. Know the minimum daily sensible water loss in the kidneys.
10. Know characteristics of the following disorders
 Dehydration
 Hypotonic hydration
 Hyponatremia
 Edema
 Hypoproteinemia
11. Know the basic characteristics of Addison’s disease
12. Know the following concerning sodium balance
 Know the salts that that account for most of the sodium in the body
 Know where sodium reabsorption takes place in the kidneys
 Know the relationship between sodium reabsorption and water reabsorption; what this does to
blood volume and blood pressure
 Know how aldosterone and ANP affect sodium balance, blood pressure and volume.
 Know how the sex hormones estrogen and progesterone affect sodium reabsorption.
13. Know the following concerning potassium balance
 Know that potassium is the chief intracellular ion
 Know what happens when potassium levels are low or high; how it affects the body.
 Know where potassium is reabsorbed
 Know that the collecting duct makes the final determination on potassium secretion and levels.
 Know how aldosterone affects potassium secretion.
14. Know the following concerning calcium balance
 PTH regulates calcium ion levels in the blood
 Know how PTH regulates calcium levels in the blood
 Know where calcium is reabsorbed in tubules of kidneys
15. Know the sources of acids in the body
 Ketones; phosphoric acids; lactic acids; carbon dioxide transport.
16. Know the following about the chemical buffering system
 Know how the bicarbonate buffer system works
 Know what an alkaline reserve is.
 Know how the phosphate buffer system works
 Know how the protein buffer system works
 Distinguish between strong and weak acids and bases
 Know that bases are proton acceptors that make pH rise; acids are proton donors that make pH
fall.
17. Describe how the respiratory system influences acid-base levels in the body.
 Know what occurs when carbon dioxide is released from the body too fast causing pH to rise.
 Know what happens when carbon dioxide is held in the body for too long and causing pH to fall.
18. Know the importance of bicarbonate as a buffer.
19. Know how bicarbonate is conserved or produced
 Conserving bicarbonate
o See figure 26.12
o PCT tubule cells are not permeable to bicarbonate!
o Bicarbonate in filtrate combines with hydrogen ions and eventually split into carbon
dioxide which moves passively into PCT tubule cells and then combines with water. This
produces carbonic acid which then spits into bicarbonate which is reabsorbed into blood
capillaries. Hydrogen ion is transported via secondary transport into filtrate and
combines with more bicarbonate.
 Generation of new bicarbonate
o Figure 26.13
o Water and carbon dioxide combine to produce carbonic acid which splits into
bicarbonate which moves via secondary active transport (antiport with chloride) into
capillaries (reabsorption). Hydrogen ions combine to produce phosphoric acid which is
excreted in urine
o Occurs in collecting duct.
 NH4 excretion
o Figure 26.14
o Glutamine amino acid in PTC cells undergoes deamination. Splits into bicarbonate and
ammonium. Bicarbonate reabsorbed into the blood (secondary active cotransport with
sodium) and ammonium is secreted into filtrate and eliminated in urine.