Book Questions for Quiz 1 Flashcards
Which one of the following is the least involved in regulating plasma Ca, Mg, and PO4 levels?
a. kidney
b. parathyroid gland
c. bone
d. hypothalmic-pituitary axis
e. GI tract
d. hypothalamic-pituitary axis
The free cytoplasmic Ca concentration is normally about how many times lower than the plasma concentration?
10,000
Appox. what percentage of plasma Ca is normally protein-bound?
40%
Which one of the following attributes is best associated with Ca?
a. activates PKA
b. intracellular 2nd messenger
c. urinary buffer
d. second most plentiful cytoplasmic cation
e. normally chelated cytoplasmic ATP
b. intracellular 2nd messenger
What percentage of Ca traversing the canine intestinal lumen is normally absorbed each day?
40%
Intestinal calcium absorption is reduced by:
glucocorticoids
Which one of the following normally has the lowest renal reabsorption efficiency?
a. tyrosine
b. PO4
c. glucose
d. Ca
e. Mg
b. PO4
Which one of the following typically has the highest absorption efficiency in the GI tract, and is not bound in the plasma to protein?
a. Ca
b. PTH
c. PO4
d. Mg
e. Insulin
c. PO4
Renal diseases affecting the proximal tubules could have profound influences on the plasma concentration of which of the following?
a. Ca
b. glucose
c. PO4
d. tyrosine
e. all of the above
e. all of the above
Phosphate is found in erythrocytes in association with:
membrane-bound phospholipids, 2,3-BPG, carbohydrate metabolism intermediates, ATP
PTH, either directly or indirectly, stimulates all of the following, except:
a. bone resorption
b. adenyl cyclase activity in its target cells
c. renal Ca absoprtion
d. renal PO4 reabsorption
e. renal vit D activation
d. renal PO4 reabsorption
Which of the following is/are true?
a. osteoblasts possess 1,25(OH)2D receptors
b. osteoclasts possess CT receptors
c. osteoblasts are capable of producing cytokines that activate osteoclasts
d. osteoblasts possess PTH receptors
e. all of the above
e. all of the above
Which one of the following exerts the greatest positive influence on PTH release?
a. stress
b. a low serum ionized PO4 concentration
c. a low serum ionized Ca concentration
d. a low serum ionized Mg concentration
e. estrogen
c. a low serum ionized Ca concentration
Select the true statements below regarding the kidneys and the Ca/PO4 homeostasis:
a. PTH promotes Ca reabsorption and urinary PO4 concentrations
b. loop diuretics promotes Ca retention
c. PTH promotes HCO3 retention and urinary Ca excretion
d. thiazide diuretics enhance urinary Ca excretion
e. all of the above
a. PTH promotes Ca reabsorption and urinary PO4 excretion
The circulating half life of PTH in mammals is about:
20 min
Pseudohyperparathyroidism is due to elevated serum levels of:
PTH
Which portions of the functional nephron have no PTH receptors?
CDs