Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

S2 - Mini #4 > Calcium and Phosphate Balance: Biochemistry & Physiology > Flashcards

Calcium and Phosphate Balance: Biochemistry & Physiology Flashcards

1
Q

Which of the following are physiological functions of calcium?

A. Maintenance of skeletal structure

B. Essential role in energy metabolism

C. Intracellular messenger activity

D. Regulation of blood pH

E. Stabilizes DNA and RNA molecules

A

A, C, and E

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

A 21-year-old man appears at the emergency department complaining of palpitations. Subsequent laboratory tests show that the calcium in his plasma is above the normal range (16.0 mg/dL). If this mineral maintains its normal ratio of free to complexed/bound, what is the concentration of free calcium in this man’s plasma (in mg/dL)?

A. 1.6 mg/dL

B. 7.2 mg/dL

C. 8.0 mg/dL

D. 9.6 mg/dL

E. 12.0 mg/dL

F. 16.0 mg/dL

G. 32.0 mg/dL

A

C

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Under normal circumstances, approximately how much calcium and phosphate combined is contained in bone?

A. 25 mg

B. 500 mg

C. 1000 mg

D. 1.5 g

E. 25 g

F. 600 g

G. 1000 g

H. 1.5 kg

A

H. 1.5 kg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Which of the following foods contain significant quantities of both phosphate and calcium?

A. Carbonated soda

B. Cheese

C. Wheat

D. Cod filet

E. Nonfat milk

A

B, C, D, and E

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Approximately how much of the total calcium in the body is contained within cells?

A. Less than 1 percent

B. Between 1 and 2 percent

C. Between 10 and 20 percent

D. Between 80 and 90 percent

E. Between 90 and 99 percent

F. Over 99 percent

A

B

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Which of the following hormones are water soluble with half-lives measured in minutes not hours?

A. Calcitonin
B. Calcitriol
C. Fibroblast Growth Factor-23
D. Parathyroid hormone
E. Parathyroid hormone-related peptide

A

A, C, D, and E

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

In a person who is under stress, cortisol-induced catabolism of bone matrix has resulted in a transient 5 percent increase in plasma calcium. In parathyroid cells, how do levels of cytosolic calcium and cyclic AMP change as this occurs, and how does PTH secretion change?

A. 1

B. 2

C. 3

D. 4

E. 5

F. 6

A

C

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the direct effects of 1,25(OH)2VitaminD3 on parathyroid cells?

A. Inhibit expression of PTH gene and inhibit expression of calcium sensor gene
B. Inhibit expression of PTH gene and stimulate expression of calcium sensor gene
C. Stimulate expression of PTH gene and inhibit expression of calcium sensor gene
D. Stimulate expression of PTH gene and stimulate expression of calcium sensor gene

A

B

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Through what direct effects does parathyroid hormone alter plasma calcium levels?

A. Net increase in calcium transfer from bone to blood and an increase in renal calcium reabsorption

B. Net increase in calcium transfer from blood to bone and a decrease in renal calcium reabsorption

C. Net decrease in calcium transfer from bone to blood and an increase in renal calcium reabsorption

D. Net decrease in calcium transfer from blood to bone and a decrease in renal calcium reabsorption

A

A. Net increase in calcium transfer from bone to blood and an increase in renal calcium reabsorption

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the primary role of RANK-L in calcium and phosphate balance?

A. In the presence of PTH, RANK-L signals osteoblasts to mature and increase calcium salt deposition into bone matrix

B. In the presence of PTH, RANK-L signals osteoclasts to mature and increase calcium salt mobilization from bone matrix

C. In the presence of calcitriol, RANK-L signals osteoblasts to mature and increase calcium salt deposition into bone matrix

D. In the presence of calcitriol, RANK-L signals osteoclasts to mature and increase calcium salt mobilization from bone matrix

A

B. In the presence of PTH, RANK-L signals osteoclasts to mature and increase calcium salt mobilization from bone matrix

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the physiological role of PTHrP in adults?

A. It assists in creating a calcium-rich milk for lactation

B. It promotes calcium salt deposition in many tissues

C. It binds to the PTH receptor and does the same thing as PTH

D. It acts to oppose the effects of PTH on calcium balance

E. It has no physiological role

A

A. It assists in creating a calcium-rich milk for lactation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the physiological role of calcitonin in adults?

A. It assists in creating a calcium-rich milk for lactation

B. It promotes calcium salt deposition in many tissues

C. It binds to the PTH receptor and does the same thing as PTH

D. It acts to oppose the effects of PTH on calcium balance

E. It has no physiological role

A

D. It acts to oppose the effects of PTH on calcium balance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Individuals who consume no Vitamin D in their diets may still have a normal calcium balance. For such individuals, production of cholecalciferol, calcidiol, and then calcitriol involves several organs. What is the correct synthesis pathway for this hormone?

A. Renal production of cholecalciferol, hepatic calcidiol synthesis, and then sunlight- induced production of calcitriol

B. Renal production cholecalciferol, sunlight-induced calcidiol synthesis, and then hepatic production of calcitriol

C. Sunlight-induced production of cholecalciferol, hepatic calcidiol synthesis, and then renal production of calcitriol

D. Sunlight-induced production of cholecalciferol, renal calcidiol synthesis, and then hepatic production of calcitriol

E. Hepatic production of cholecalciferol, renal calcidiol synthesis, and then sunlight- induced production of calcitriol

F. Hepatic production of cholecalciferol, sunlight-induced calcidiol synthesis, and then renal production of calcitriol

A

D. Sunlight-induced production of cholecalciferol, renal calcidiol synthesis, and then hepatic production of calcitriol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the primary effect of calcitriol in humans?

A. Increase renal calcium reabsorption and increase renal phosphate reabsorption

B. Increase renal calcium reabsorption and decrease renal phosphate reabsorption

C. Increase mobilization of calcium and phosphate from bone matrix

D. Increase absorption of calcium and phosphate from the GI tract lumen

E. Increase secretion of FGF-23 and increase secretion of PTH F. Increase secretion of FGF-23 and decrease secretion of PTH

A

D. Increase absorption of calcium and phosphate from the GI tract lumen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Which of the following hormones cannot directly affect plasma calcium but can directly decrease plasma phosphate?

A. Calcitonin
B. Calcitriol
C. Fibroblast Growth Factor-23
D. Parathyroid hormone
E. Parathyroid hormone-related peptide?

A

C. Fibroblast Growth Factor-23

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Which of the following hormones acts to increase secretion of two other hormones?

A. Calcitonin
B. Calcitriol
C. Fibroblast Growth Factor-23
D. Parathyroid hormone
E. Parathyroid hormone-related peptide

A

D. Parathyroid hormone

17
Q

Which of the following is an indirect effect of parathyroid hormone?

A. Increase in calcium reabsorption from the kidney

B. Decrease in phosphate reabsorption from the kidney

C. Increase in calcium mobilization from bone matrix

D. Increase in phosphate mobilization from bone matrix

E. Increase in calcium absorption from the GI tract

A

E. Increase in calcium absorption from the GI tract

18
Q

In the kidney, a precursor molecule can be modified two ways. One product is the active form of Vitamin D and the other is inactive. What is this precursor molecule, and which of its carbons’ hydroxylations is specifically stimulated by PTH and inhibited by FGF-23?

A. Cholecalciferol, carbon 1

B. Cholecalciferol, carbon 24

C. Cholecalciferol, carbon 25

D. Calcidiol, carbon 1

E. Calcidiol, carbon 24

F. Calcidiol, carbon 25

A

D. Calcidiol, carbon 1

19
Q

Where is the Vitamin D receptor and what binds to it?

A. On the cell surface, bound by either ergocalciferol or cholecalciferol

B. Inside the cell, bound by either ergocalciferol or cholecalciferol

C. On the cell surface, bound by calcidiol

D. Inside the cell, bound by calcidiol

E. On the cell surface, bound by calcitriol

F. Inside the cell, bound by calcitriol

A

F. Inside the cell, bound by calcitriol

20
Q

Which of the following are risk factors associated with Vitamin D deficiency?

A. Sedentary lifestyle
B. Indoor environment with little to no sun exposure
C. Vegan diet lacking supplements
D. Darker skin color
E. Living in polar regions, either north or south of the equator

A

B, C, D, and E

21
Q

What is the most typical cause of secondary hyperparathyroidism?

A. Chronic kidney disease

B. Indoor environment with little to no sun exposure

C. Vegan diet lacking supplements

D. Liver failure

E. Pituitary adenoma

A

A. Chronic kidney disease

S2 - Mini #4 (18 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions