Brainscape's Knowledge GenomeTM

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


See full index

D1 Fall - Biochem > 11/15: Calcium and Phosphorus II > Flashcards

11/15: Calcium and Phosphorus II Flashcards

1
Q

How does chronic kidney disease affect calcium and phosphate homeostasis?

A

By disrupting the Ca and Pi reabsorption process

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

What defines hypocalcemia?

A

When total serum calcium concentrations are less than 8.5 mg/dL
Or serum ionized calcium less than 4.4 mg/dL

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

What are the symptoms of hypocalcemia?

A

Muscle cramps
Increased neuromuscular excitability Muscle spams
Fatigue
Cardiac dysfunction
Depression, psychosis, seizures

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

what is hypoparathyroidism?

A

Undersecretion of PTH

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

what leads to hypoparathyroidisms?

A

Hypocalcemia that also has serum PTH that is really low

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

what are the common causes of hypoparathyroidisms?

A

autoimmune

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

what is DiGeorges syndrome?

A

Congenital disease that causes a lack of the parathyroid glan

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

Is hypoparathyroidism associated with CaSR mutations?

A

yes

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

how is hypoparathyroidism associated with CaSR mutations?

A

By consitutively activating CaSR causing hypocalcemia since PTH becomes
inhibited leading to low Ca reabsorption

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

How do you treat hypoparathyroidism?

A

Calcium and calcitriol

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

What occurs in this disease (hypocalcemia)?

A

Serum PTH is high to overcome the resistance to increase low Ca levels

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

what can a Vit. D deficiency lead to in children?

A

rickets

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

what can a Vit. D deficiency lead to in adults?

A

Osteomalacia

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

what is VDDR type 1?

A

Pseudovitamin D deficiency

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

what causes VDDR type I

A

Defect in renal 25-OH-Vit. D 1-alpha hydroxylase

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

Is 1,25(OH)2D3 high or low in VDDR type 1?

A

very low

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What causes VDDR type 2?

A

Defect in Vit. D receptor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Is 1,25(OH)2D3 high or low in VDDR type 2?

A

High

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

How do you treat primary hyperparathryoidism?

A

surgery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Can inactivating mutations of CaSR cause familial primary hyperparathryoidism?

A

yes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What occurs in this disease (hypercalcemia)?

A

Oversecretion of PTH due to hypocalcemia or decreased 1,25(OH)2D3
b. Renal failure

22
Q

what defines hypophosphatemia?

A

<2.5-4.5 mg/dL of Pi

23
Q

what is X-linked hypophosphatemic rickets (XLH)?

A

PHEX gene on X-chromosome gets mutated causing bone deformities

24
Q

what does PHEX normally do?

A

Inhibits FGF23 production

25
Q

what does XLH mutation do?

A

Causes inactive PHEX so FGF23 is increased

26
Q

How do you treat XLH?

A

. Phosphate supplementation
b. High calcitriol

27
Q

What are the two forms of hypophosphatemic rickets?

A

Autosomal dominant
b. Autosomal recessive

28
Q

What causes autosomal recessive hypophosphatemic rickets?

A

a.Mutations in DMP1
i. Causes overproduction of FGF23

29
Q

What causes hereditary hypophosphatemic rickets?

A

Loss of function mutations in NaPiIIc

30
Q

What is tumor induced osteomalacia?

A

An acquired syndrome of renal phosphate wasting

31
Q

What does the condition cause?

A

Secretion of factors into the blood like FGF23

32
Q

what defines hyperphosphatemia?

A

Phosphate > 4.5mg/dL or >1.5mM

33
Q

what are the symptoms of acute hyperphosphatemia?

A

Hypocalcemia

34
Q

what are the symptoms of chronic hyperphosphatemia?

A

Soft tissue calcification
Renal failure

35
Q
A
36
Q

What causes autosomal dominant hypophosphatemic rickets?

A

Mutations in FGF23 causing its increase

37
Q

How does renal failure cause hypercalcemia?

A

Due to the kidneys being unable to produce 1,25(OH)2D3 which inhibits PTH

38
Q

Is secondary hyperparathyroidism a condition of hypercalcemia?

A

no

39
Q

What causes hypercalcemia of malignancy?

A

Tumors that secrete factors that stimulate bone resorption

40
Q

What occurs to cause familial primary hyperparathryoidism in this instance?

A

CaSR inactive so high Ca levels are not sensed leading to elevated PTH since parathyroid gland reads Ca levels as low

41
Q

What occurs in MEN2A?

A

Gain of function mutation in RET protooncogene

42
Q

What occurs in MEN1?

A

Menin tumor suppressor gene inactivated

43
Q

What are the two types of familial primary hyperparathryoidism?

A

MEN1 (Mutiple Endocrine Neoplasia)
b. MEN2A

44
Q

what can primary hyperparathyroidism cause?

A

Hypercalcemia
Low Pi
High bone turnover
Kidney stones

45
Q

what causes primary hyperparathyroidism?

A

Oversecretion of PTH without a negative feedback on it

46
Q

what are the symptoms of hypercalcemia?

A

Fatigue
EKG abnormalities
Nausea, vomiting, constipation Anorexia
Abdominal pain
Hypercaciuria
Calcification of soft tissues Hypercalcemic crisis

47
Q

what defines hypercalcemia?

A

Serum total calcium >10.5 mg/dL
Ionized calcium >5.4 mg/dL

48
Q

What is VDDR type 2?

A

a. Hereditary vitamin D resistant rickets

49
Q

what are the two types of Vit. D deficient rickets?

A

Type 1
Type 2

50
Q

How does a lack of Vit. D inhibit Ca and Pi uptake?

A

Due to calcium transport proteins relying on Vit D to function, so without it they do
not work

51
Q

What causes pseudohypoparathyroidism?

A

Hypocalcemia due to lack of sensitivity to PTH on tissues

52
Q

How can you treat hypoparathyroidism?

A

Calcium and calcitriol supplements

D1 Fall - Biochem (29 decks)

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