26. Fluid and Electrolyte Balance, Acid Base Balance

Electrolyte Balance

Open Question
Explain why and how total body sodium content, ECF volume, and blood pressure are jointly regulated.
Open Question
Explain how Na ⁺ balance, ECF volume, and blood pressure are jointly regulated.
Open Question
Mrs. Bush, a 70-year-old woman, is admitted to the hospital. Her history states that she has been suffering from diarrhea for three weeks. On admission, she complains of severe fatigue and muscle weakness. A blood chemistry study yields the following information: Na⁺ 142 mEq/L; K⁺ 1.5 mEq/L; Cl ⁻ 92 mEq/L; Pco₂ 32 mm Hg. Which electrolytes are within normal limits? Which are so abnormal that the patient has a medical emergency? Which of the following represents the greatest danger to Mrs. Bush?a. a fall due to her muscular weakness,b. edema,c. cardiac arrhythmia and cardiac arrest.
Open Question
Which of the following is false with respect to sodium ions in human physiology?

a. Sodium ions are the most abundant extracellular cation.
b. Sodium ions are an important osmotic particle in the ECF.
c. The entry of sodium ions into a cell causes depolarization.
d. Sodium ions are more concentrated in the cytosol than in the ECF.
Open Question
List the effects of each of the following hormones on electrolyte balance. Note that some hormones affect more than one electrolyte.

a. Angiotensin-II
b. Aldosterone
c. Parathyroid hormone
d. Vitamin D
e. Atrial natriuretic peptide
Open Question
Which of the following effects tend to be caused by hypernatremia?

a. Inhibition of ADH secretion
b. Cellular crenation
c. Cellular swelling
d. Increased urine production
Open Question
Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

a. Potassium ions are responsible for the repolarization phase of the action potential.
Open Question
Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

b. Insulin, aldosterone, and epinephrine stimulate the uptake of potassium ions into cells.
Open Question
How does an electrolyte differ from a nonelectrolyte?
Open Question
Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

c. Hyperkalemia tends to decrease the resting membrane potential and hyperpolarize excitable cells.
Open Question
Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

d. Hypocalcemia causes neurons to become hyperexcitable, leading to potential tetanic contractions.
Open Question
Your friend argues that all water conducts electricity, regardless of what it contains. You prepare three liquids to test this hypothesis: one with deionized water (with no solutes, only water molecules), one with 5% glucose in water, and one with 5% sodium chloride in water. Which of these solutions, if any, will conduct an electric current? Explain.
Open Question
What happens to the concentration of sodium ions in the ECF if you consume a large amount of salt without consuming any water? How will this affect the osmotic pressure of the ECF? Why could this lead to an elevation in blood pressure? (Connects to Chapter 19)See answers in Appendix A.
Multiple Choice
Parathyroid hormone (PTH) increases Ca²⁺ deposition in the bones.
Multiple Choice
The most important factor that influences K⁺ secretion is __________.