Session 5 - Kalcium and the Cidney (intentional, promise) Flashcards Preview

Semester 3 - Urinary > Session 5 - Kalcium and the Cidney (intentional, promise) > Flashcards

Flashcards in Session 5 - Kalcium and the Cidney (intentional, promise) Deck (48)
Loading flashcards...
1

Give five functions of Calcium

• Muscle contraction
• Inactivation/activation of enzymes
• Nerve conduction
• Exocytosis
• Hormone secretion
• Haemostasis

2

What is the physiologically active from of Ca2+?

• Ionised form

3

Give the three forms in which Ca2+ is found in the body

• Free ionised species
• Protein bound
• Complexed

4

How much of dietary calcium is absorbed?

• 20-40% is absorbed (25mmol)

5

When does calcium absorption increase? (3)

• Growing children
• Pregnancy
• Lactation

6

How much calcium do the kidney filter per day?

• 250mmol

7

How much of the body's calcium reservoir is found in the ECF?

• 1%

8

What chemical is responsible for the absorption of calcium from the gut?

• 1,25 - OH 2D control

9

Where is the majority of calcium reabsorption in the kidney?

• 65% reabsorbed in proximal tubule
• 20-25% recovered in ascending loop of henle
• 10% recovered in DCT under control of PTH

10

What is the standard 24hr urinary calcium excretion?

• <10 mmol

11

How much calcium filtered by kidney per day?

250 mmol

12

Give the actions of PTH

• Increases reabsorption in kidney
• Increases breakdown of bone

Converts calciferol to calcitriol in kidney

13

What is the inactive form of Calcitriol called?

Calciferol

14

What are the actions of calcitriol?

• Increase breakdown of bone
• Increase reabsorption in kidney

Increase absorption of calcium from gut

15

How is vitamin d2 produced?

• By gut

16

How is vitamin d3 produced?

• By skin

17

How does vitamin D become calciferol?

• Hydroxylation in the liver

18

When does calciferol become calcitriol?

• After 2nd hydroxylation

19

How is Calcium release regulated?

• Negative feed back to parathyroid gland
• Gq receptor inhibit PTH release
• Reduce further calcium absorption

20

What are the three major causes of hypercalcaemia?

• Primary hyperparathyroidism
• Haemtological malignancies
• Non-haematological malignancies

21

How do malignancies cause hypercalcaemia?

• PTHrp released
• Does not convert calciferol to calcitriol

22

Give four systems that hypercalcaemia causes symptoms in

• Gastrointestinal
• Cardiovascular
• Renal
• CNS

23

Give four gastrointestinal symptoms of hypercalcaemia

• Anorexia
• Nausea/Vomiting
• Constipation

24

Give three cardiovascular consequences of hypercalcaemia

• Hypertension Shortened QT
• Enhanced sensitivity to digoxin

25

Give three renal consequences of hypercalcaemia

• Polyuria
• Polydipsia
• Nephrocalcinosis

26

Give three cognitive effects of hypercalcaemia on the CNS

• Cognitive difficulties
• Apathy
• depression

27

Outline treatments for hypercalcaemia

General measures
• Hydration - Increase Ca2+ excretion
• Loop diuretics - Increase Ca2+ excretion
Specific measures
• Bisphosphonates - Inhibit breakdown of bone
• Calcitonin - Opposes the action of PTH
Treat underlying condition

28

What percentage of people will develop kidney stones in their life?

• 20% mean
• 5-10% of women

29

What is the most common form of kidney stone?

• 70-80% made of calcium

30

What factors are involved in the formation of kidney stones?

• Low urine volume
• Hypercalcuria

Low urin pH