Regulation of Calcium and Phosphate Metabolism Flashcards Preview

NeuroEndo Test 3 > Regulation of Calcium and Phosphate Metabolism > Flashcards

Flashcards in Regulation of Calcium and Phosphate Metabolism Deck (73)
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1

Free, ionized Ca2+ is the biologically ___ form.

active

2

____ symptoms include hyperreflexia, spontaneous twitching, muscle cramping, tingling, and numbness.

Hypocalcemia

3

____ sign is twitching of the facial muscles elicited by tapping on the facial nerve and indicates _____.

Chvostek; hypocalcemia

4

____ sign is carpopedal spasm upon inflation of a BP cuff and indicates ____.

Trousseau; hypocalcemia

5

____ symptoms include decreased QT interval, constipation, lack of appetite, polyuria, polydipsia, muscle weakness, hyporeflexia, lethargy, and coma.

Hypercalcemia

6

Hypocalcemia reduces the activation threshold for Na+ channels, so it is ___ to evoke an AP, which results in membrane excitability.

easier

7

Generation of spontaneous APs is the physical basis for hypocalcemic ____ and produces tingling, numbness, and spontaneous muscle twitches.

tetany

8

Hypercalcemia causes ____ membrane excitability, so the nervous system becomes depressed and reflex responses are slowed.

decreased

9

An increase in plasma protein concentration ____ total Ca2+ concentration.

increases

10

An increase in Ca2+ complexed with anions will ____ ionized Ca2+ concentration.

decrease

11

Acid-base abnormalities will alter the ionized concentration of Ca2+ by changing the fraction of Ca2+ bound to ____.

albumin

12

Acidemia ____ free ionized Ca2+ concentration because ___ Ca2+ is bound to albumin.

increases; less

13

Alkalemia _____ free ionized Ca2+ concentration because ___ Ca2+ is bound to albumin.

decreases; more

14

Alkalemia is often accompanied by _____.

hypocalcemia

15

Extracellular concentration of Pi is ___ related to that of Ca2+.

inversely

16

The chief cells of the parathyroid glands synthesize and secrete ___.

PTH

17

PTH is stimulated to be secreted when there are ___ levels of plasma Ca2+.

low

18

High extracellular Ca2+ concentration ____ PTH synthesis and secretion.

inhibits

19

Chronic hypercalcemia causes ___ synthesis and storage of PTH, ___ breakdown of stored PTH, and release of inactive PTH fragments into circulation.

decreased; increased

20

Chronic hypocalcemia causes ___ synthesis and storage of PTH and hyperplasia of parathyroid glands (secondary hyperparathyroidism).

increased

21

Severe hypomagnesemia (ie alcoholism) ____ PTH synthesis, storage, and secretion.

inhibits

22

PTH acts as a ___.

GPCR

23

Decreased plasma Ca2+ concentration leads to ___ PTH secretion. This leads to ___ bone resorption; ___ Pi reabsorption, ___ Ca2+ reabsorption, and ___ urinary cAMP by the kidneys; and ___ Ca2+ absorption (indirect via VitD) by the intestine.

increased; increased; decreased; increased; increased; increased

24

____ __ promotes mineralization of new bone through its coordinated actions in the regulation of both Ca2+ and Pi plasma concentrations.

Vitamin D

25

Vitamin D ___ both Ca2+ and Pi plasma concentrations.

increases

26

PTH receptors are located on ____.

osteoblasts

27

Short-term actions of PTH include bone ____ via direct action on osteoblasts.

formation

28

Long-term actions of PTH include increased bone ___ via indirect action of osteoclasts mediated by cytokines released from osteoblasts.

resorption

29

Vitamin D acts synergistically with PTH to stimulate ____ activity and bone ____.

osteoclast; resorption

30

____ induces stem cells to differentiate into osteoclast precursors, mononuclear osteoclasts, and finally, mature, multinucleated osteoclasts.

M-CSF