Brainscape's Knowledge GenomeTM

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


See full index

MSK > Hormone regulation calcium and phosphate > Flashcards

Hormone regulation calcium and phosphate Flashcards

1
Q

What regulates calcium absorption?

A

PTH

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

What senses change in serum calcium?

A

Chief cells

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

What cause PTH release?

A

Low calcium lvls- stimulate PTH release

High calcium lvls- inhibit PTH release

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

Does parathyroid hormone cause slow or fast response?

A

Fast response

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

Mechanism of PTH?

A

Ca2+ binds to receptor
Intracellular cascade (Gq cascade)
Ca2+ released from ER

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

State 4 effects of PTH?

A

1) IncreaseCa2+ reabsorption in kidneys- decreasing urinary Ca2+ excretion
2) Increases Ca2+ reabsorption in small intestine
3) Stimulates osteoclast break bone down- release Ca2+ and phosphorous
4) Stimulate formation of active form of vitamin D (1α,25-dihydroxyvitamin D)

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

State 3 effects of vitamin D?

A

1) Amplify PTH
2) Stimulate vit D prod in kidney- cause Ca2+ and phosphate reabsorption
3) Stimulate osteoclasts break bone into Ca2+ and phosphate

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

Function calcitonin?

A

Anti PTH

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

What produces calcitonin?

A

Thyroid- C cells

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

When is calcitonin released?

A

High plasma concentration of Ca2+

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

What is released when high conc of Ca2+?

A

C cells of thyroid release calcitonin

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

Effects of calcitonin?

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

Where is vitamin D synthesised?

A

Skin- exposure to sunlight
Metabolised in liver and kidney to form 1α,25-dihydroxyvitamin D

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

Outline how vitamin d is activated (flow diagram)

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

How is vitamin D activated?

A

1) UV light hits skin
2) 7-dehydrocholesterol
3) Cholecalciferol (vit D3)
4) 25-hydroxylase catalyses reaction
5) 25-hydroxyvitamin D3 formed
6) 1-alpha-hydroxylase catalyses reaction
7) Forms 1,25-dihydroxyvitamin D3
(calcitrol)

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

What is the active form of vitamin D called?

A

1,25-dihydroxyvitamin D3
(calcitrol)

17
Q

What enzyme is involved in cholecalciferol to 25 hydroxyvitamin D3?

A

25-hydroxylase

18
Q

What enzyme is involved in 25-hydroxyvitamin D3 to 1, 25 dihydroxyvitamin D3 (calcitrol)

A

1 alpha hydroxylase

19
Q

What sets off chain for activation of vit D3?

A

UV light hitting skin
Converts 7-dehydrocholesterol to cholecalciferol

20
Q

Where does the activation of vit D3 occur?

A

1) Skin
2) Liver (cholecalciferol to 25-hydroxyvitamin D3 (calcidiol))
3) Kidney (25 hydroxyvitamin D3 to 1,25 dihydroxyvitamin D3 (Calcitriol)

21
Q

Outline vit D3 formation?

A

1) Initially skin or diet
2) Vit D hydrolysed by liver by 25-hydroxylase to form 25-hydroxyvitamin D (calcidiol)
3) Kidney hydrolyses it using 1-hydroxylase to form 1,25-dihydroxyvitamin D (calcitriol)

22
Q

What stimulates hydrolysis of vit D3 in kidneys?

A

PTH

23
Q

What inhibits vit D3 activation?

A

High calcitriol- inhibit Pth

24
Q

What effects does calcitonin have?

A

1) Block PTH release
2) SI- inhibit Ca2+ absorption
3) Stop Ca2+ and phosphate release from bone
4) Kidney- inhibit Ca2+ reabsorption

25
Q

Give one function of bone related to Ca2+?

A

Storage (buffer) of Ca2+, Phosphate and magnesium

26
Q

Give 3 functions of kidney?

A

1) Respond Ca2+, PTH, vit D and calcitonin
2) Activate vit D
3) Regulate calcium and phosphate reabsorption/exc

27
Q

Function of parathyroid hormones?

A

1) Respond to changes in serum calcium
2) Synthesis and secretion PTH

28
Q

What stimulates PTH?

A

Low lvls serum calcium

29
Q

Function of GI tract?

A

1) Absorb Ca2+ and phosphate

30
Q

Function thyroid glands?

A

1) Respond changes in serum calcium
2) Synthesis and excretion of calcitonin

31
Q

What secretes calcitonin?

A

Thyroid glands

32
Q

Effect of PTH on:
Intestine
Kidney
Bone
Net effect serum lvl?

A

Intestine- increased calcium and phosphate absorption
Kidney- decreased calcium excretion
increased phosphate excretion
Bone- calcium and phosphate resorption
Serum- calcium increase, phosphate decrease

33
Q

Effect of vit D on:
Intestine
Kidney
Bone
Net effect serum lvl?

A

Intestine- increased Ca2+ and phosphate absorption
Kidney- decreased excretion
Bone- bone formation increased
Serum- both increase

34
Q

What growth factor is involved in phosphate regulation?
Function?

A

FGF23
Suppress phosphate reabsorption

MSK (16 decks)

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