Parathyroid hormone (PTH) increases Ca²⁺ deposition in the bones.

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.

Which of the following statements correctly describe(s) the role of aldosterone?

a. Aldosterone triggers sodium ion and so water reabsorption.

b. Aldosterone triggers potassium ion secretion.

c. Aldosterone triggers hydrogen ion secretion.

d. Both a and b are correct.

e. All of the above are correct.

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.

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?