Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Endocrinology > Calcium metabolism and Disorders > Flashcards

Calcium metabolism and Disorders Flashcards

(63 cards)

Start Studying
1
Q

where do you get vitamin D from

A

skin and diet

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

where is vitamin D converted

A

the liver

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

what does PTH do to vit D and calcium

A

stimulates the phosphorylation of vit D and reduces calcium (in bone, increases it in serum)

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

what is the main stimulus of PTH

A

low serum calcium

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

what senses serum calcium

A

calcium sensing receptor (C ASR) (GPCR)

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

describe how the mineralised aspects of bone are formed

A

inorganic pyrophosphate turns into inorganic phosphate- by alkaline phosphatase- which joins to calcium to make hydroxyapatite

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

what promotes bone mineralisation

A

PTH (elevated serum calcium promotes bone mineralisation) and sclerostin

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

what can make you loose the ability to metabolise vit D

A

renal failure, nephrectomy, hypoparathyroidism, anticonvulsants

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

what are the general symptoms of hypercalcaemia

A

Bones (ache)
Stones (kidney stones)
Abdominal Groans
Psychic Moans

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

what are the acute symptoms of hypercalcaemia

A

Thirst
Dehydration
Confusion
Polyuria

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

what are the chronic effects and symptoms of hypercalcaemia

A 
Myopathy
Fractures
Osteopaenia
Depression
Hypertension
Pancreatitis
Duodenal ulcer
Renal calculi
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

how do you investigate hypercalcaemia

A

PTH

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

what can cause hypercalcaemia with a low PTH

A

bone pathology

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

what do you check in hypercalcaemia with a low PTH

A

ALP

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

what can cause hypercalcaemia with a low PTH and a high ALP

A

Metastases
Sarcoidosis
Thyrotoxicosis

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

what can cause hypercalcaemia with a low PTH and a low ALP

A

Myeloma
Vit D Toxicity
Milk-Alkali (take too many rennie make gut alkaline
Thyrotoxicosis, sarcoid, HCO3

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

what do you check in hypercalcaemia with high/normal PTH

A

urine calcium excretion

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

what can cause hypercalcaemia with a high/normal PTH and a low urine calcium excretion

A

FHH- Familial Hypercalcemic Hypocalciuria

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

what can cause hypercalcaemia with a high/normal PTH and a high urine calcium excretion

A

primary/ tertiary hyperparathyroidism

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

what drugs can cause hypercalcaemia

A

Vit D, thiazides

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

what are the most common causes of hypercalcaemia

A

Primary Hyperparathyroidism

Malignancy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what diseases can cause hypercalcaemia

A

Primary Hyperparathyroidism
Malignancy
Granulomatous Disease eg Sarcoid, TB
Familial Hypocalciuric Hypercalcaemia
High turnover: bedridden, thyrotoxic, Pagets
Tertiary hyperparathyroidism (usually renal disease)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

how do thiazides cause hypercalcaemia

A

reduce ability to secrete calcium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

how do you diagnose primary hyperparathyroidism

A

Raised serum calcium
Raised serum PTH (or inappropriately normal)
Increased urine calcium excretion
Ensure Vitamin D replete

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
how does malignancy cause hypercalcaemia
Metastatic Bone destruction PTHrp (PTH related peptide) from solid tumours Osteoclast activating factors
26
how do you diagnose hypercalcaemia due to malignancy
Raised calcium and alkaline phosphatase (and a low PTH) X-ray, CT, MRI Isotope Bone Scan
27
what is the acute treatment for hypercalcaemia
fluids- saline Consider loop diuretics once rehydrated- avoid thiazides Bisphosphonates- single dose will lower Ca over 2-3d, maximum effect at 1 week Steroids occasionally used e.g Pred 40-60mg/day for sarcoidosis
28
what can reduce calcium in metastatic disease
chemotherapy
29
what is the management for primary hyperparathyroidism
surgery Cinacalcet- Cacium Mimetic (mimic calcium on PTH receptor, reduced PTH secretion) Can be useful if need treatment, but unfit for surgery
30
what are the indications for a parathyroidectomy
``` End Organ Damage: Bone disease (Osteitis Fibosa et cystica; brown tumours/ pepper pot skull) Gastric ulcers Renal stones Osteoporosis ``` very high calcium (>2.85) under age 50 eGFR<60
31
why is the treatment for osteoporosis PTH when hyperparathyroid causes osteoporosis
PTH in non continuous injection (non pulsuatile as normal) will get rid of receptors and have paradoxical effect to normal affect of PTH on bone
32
what is secondary hyperparathyroidism
Physiological response to low calcium or vit D
33
what is tertiary hyperparathyroidism
Parathyroid becomes autonomous after many years of overactivity e.g renal failure
34
what is primary hyperparathyroidism
Primary overactivity of Parathyroid gland i.e adenoma or carcinoma
35
what genetic syndromes are linked to hypercalcaemia
MEN1/ 2 -Will almost always have developed a parathyroid adenoma with hypercalcaemia at a young age Familial isolated hyperparathyroidism -Adenoma as in primary hyperparathyroidism
36
what is familial hypocalciuric hypercalcaemia
condition where a deactivating mutation in the calcium sensing receptor (CaSR) causes increased PTH production + low calcium in urine = increased serum calcium
37
what inheritance pattern does FHH follow
autosomal dominant
38
what is the severity of FHH
usually benign/ asymptomatic
39
what are the tests for FHH
Mild Hypercalaemia Reduced urine calcium excretion PTH may be (marginally) elevated Genetic Screening
40
what are the signs and symptoms of hypocalcaemia
``` Paraesthesia - fingers, toes, perioral Muscle cramps, tetany Muscle weakness Fatigue Bronchospasm or laryngospasm Fits Chovsteks sign (tapping over facial nerve) Trousseau sign (carpopedal spasm) ECG: QT prolongation (risk of R on T, VF) ```
41
what is the treatment for acute hypocalcaemia
IV calcium gluconate (in saline or dextrose)
42
what are the possible causes of hypocalcaemia
congenital - DiGeorge (babies have no PTH) destruction (surgery, radiotherapy, malignancy) autoimmune hypomagnesaemia (functional hypoparathyroidism) idiopathic
43
what is the long term management for hypocalcaemia
calcium supplement | vit D tablets
44
how is hypomagnesaemia related to hypocalcaemia
calcium release from cells is dependent on magnesium in magnesium deficiency intracellular calcium is high PTH release in inhibited skeletal and muscle receptors less sensitive to PTH
45
what can cause hypomangesaemia
``` Alcohol Drugs -Thiazide -PPI GI illness Pancreatitis Malabsorption ```
46
what is pseudohypoparathyroidism
genetic defect (GNAS 1) that causes low calcium but PTH concentrations are high caused by PTH resistance
47
what are the features of pseudohypoparathyroidism
``` Bone abnormalities (McCune Albright) Obesity Subcutanous calcification Learning Disability Brachdactyly (4th metacarpal- short) ```
48
what is pseudo-pseudohypoparathyroidism
Albright’s Herditary Osteodystrophy with no alteration in PTH action so normal calcium
49
what can cause malabsorption of vit D
gastric surgery, coeliac disease, liver disease, pancreatic failure
50
what can cause rickets/ osteomalacia (vit D deficiency)
``` dietary deficiency malabsorption chronic renal failure lack of sunlight drugs (anticonvulsants) ```
51
what are the clinical signs of osteomalacia
``` low calcium muscle wasting (proximal myopathy) dental defects (caries, enamel) bone- tenderness, fractures, rib deformity, limb deformity waddling gate ```
52
what are common features of chronic renal disease
vit D deficiency | secondary hyperparathyroidism
53
what are the long term consequences of vitamin D deficiency
bone disease- demineralisation/ fractures osteomalacia/ rickets malignancy (esp colon), heart disease, diabetes
54
what is the chronic treatment for vit d deficiency
vit D tablets, combined calcium + vit D
55
what causes vitamin D resistant rickets
PHEX or FGF23 gene mutation | FGF 23 regulates phosphate levels in plasma and is secreted by osteocytes in response to calcitriol
56
what are the features of vitamin D resistant rickets
Low phosphate | High Vitamin D
57
what is the treatment for vitamin D resistant rickets
phosphate and Vit D supplements +/- surgery
58
``` name the disease: Ca ++ PTH ++ AP N(+) Phos - ```
primary parathyroidism
59
``` name the disease: Ca ++ PTH --- AP +++ Phos N ```
malignancy
60
``` name the disease: Ca + PTH N/+ AP N Phos N ```
FHH
61
``` name the disease: Ca -- PTH -- AP N Phos +/N ```
hypoparathyroidism
62
``` name the disease: Ca -- PTH + AP ++ Phos - ```
osteomalacia
63
``` name the disease: Ca N(+) PTH N AP ++ Phos N ```
pagets

Endocrinology (46 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions