Parathyroid and Ions

Question 1

Role of parathyroid hormone (PTH)

Answer 1

Bone resorption

Increase Ca reabsorption in kidney

Decrease PO4 reabsorption in kidney

Stimulates vit D

Question 2

Role of vit D

Answer 2

Increase Ca and PO4 absorption in gut

Increase Ca and PO4 reabsorption in kidney

Bone turnover

Question 3

Role of calcitonin

Answer 3

Reduces Ca and PO4

Absorbed into bone

Question 4

Site of calcitonin release

Answer 4

C cells of thyroid

Question 5

Effect of Mg on Ca

Answer 5

Low Mg inhibits PTH release

May cause hypocalcaemia

Question 6

Features of hyercalcaemia

Answer 6

Bones, stones, abdo groans and psychic moans

Bone pain, #s

Renal stones

Abdo pain, constipation, N/V

Confusion, weakness

Question 7

Mx of acute hypercalcaemia

Answer 7

Rehydrate

Bisphosphonate

Treat cause

Question 8

Features of hypocalcaemia

Answer 8

Cramps

Spasms

Neuromuscular excitability

Trousseau’s sign

Chvostek’s sign

Question 9

Trousseau’s sign

Answer 9

Inflate BP cuff

Wrist and fingers flex

Question 10

Chvostek’s sign

Answer 10

Tap facial nerve over parotid

Corner of mouth twitches

Question 11

Sx of severe hypophosphataemia

Answer 11

Muscle weakness

Rhabdomyolysis

RC, WC, PLT dysfunction

Arrhythmias

Question 12

Sx of hypomagnesaemia

Answer 12

Paraesthesia

Ataxia

Seizures

Tetany

Arrhythmias

Question 13

Sx of severe hypermagnesaemia

Answer 13

Neuromuscular depression

Low BP

Bradycardia

Respiratory depression

Coma

Question 14

Sx of zinc deficiency

Answer 14

Alopecia

Dermatitis

Night blindness

Diarrhoae

Question 15

Causes of primary hyperparathyroidism

Answer 15

Solitary adenoma ~80%

Hyperplasia

Question 16

Ix for primary hyperparathyroidism

Answer 16

High Ca

High PTH

Low PO4

Question 17

Mx of hyperparathyroidism

Answer 17

Fluid intake to prevent renal stones

Avoid thiazides

Excision of adenoma

Question 18

Indications for excision of parathyroid adenoma

Answer 18

High Ca

Osteoporosis

Renal stones

Reduced renal function

Age < 50 yrs

Question 19

Multiple Endocrine Neoplasia (MEN) inheritance

Answer 19

Autosomal dominant

Question 20

MEN 1

Answer 20

Parathyroid adenoma

Pancreas tumour

Pituitary prolactinoma

Question 21

MEN 2a

Answer 21

Parathyroid tumour

Medullary Thyroid cancer

Phaeochromocytoma

Question 22

MEN 1 gene

Answer 22

Tumour suppressor gene

Question 23

MEN 2b

Answer 23

Medullary thyroid cancer

Phaechromocytoma

Mucosal neuromas

Marfanoid features

Question 24

MEN 2a and b gene

Answer 24

ret proto-oncogene

Receptor tyrosine kinase

Question 25

Definition of secondary hyperparathyroidism

Answer 25

Low Ca leads to increase in PTH

Question 26

Causes of secondary hyperparathyroidism

Answer 26

Vit D deficiency CKD

Question 27

Rx of secondary hyperparathyroidism

Answer 27

Treat cause Vit D

Question 28

Tertiary hyperparathyroidism definition

Answer 28

Prolongued secondary hyperparathyroidism Parathyroid glands become hyperplastic High PTH despite high Ca

Question 29

Causes of tertiary hyperparathyroidism

Answer 29

CKD

Question 30

Definition of malignant hyperparathyroidism

Answer 30

Cancers produce PTHrP | (Parathyroid related protein)

Question 31

Cancers causing malignant hyperparathyroidism

Answer 31

Squamous cell lung cancers Breast Renal cell carcinomas

Question 32

Primary hypoparathyroidism definition

Answer 32

Gland failure Low PTH

Question 33

Ix for primary hypoparathyroidism

Answer 33

Low Ca Low PTH High PO4

Question 34

Causes of primary hypoparathyroidism

Answer 34

Autoimmune Congenital (DiGeorge)

Question 35

Rx of primary hypoparathyroidism

Answer 35

Ca Synthetic PTH

Question 36

Causes of secondary hypoparathyroidism

Answer 36

Radiation (Para) thyroidectomy Hypomagnesaemia

Question 37

Pseudohypoparathyroidism definition

Answer 37

Failure to respond to PTH

Question 38

Signs of pseudohypoparathyroidism

Answer 38

Short metacarpals Round face Short stature Low IQ Calcified basal ganglia

Question 39

Cause of pseudohypoparathyroidism

Answer 39

Genetic

Question 40

Definition of pseudopseudohypoparathyroidism

Answer 40

Same as pseudohypoparathyroidism But normal biochemistry Genetic cause

Question 41

Von Hippel-Lindau syndrome inheritance

Answer 41

Autosomal dominant

Question 42

Von Hippel-Lindau syndrome mutation

Answer 42

Tumour suppressor gene

Question 43

Von Hippel-Lindau syndrome features

Answer 43

Predisposes to bilateral renal cysts Retinal haemangioblastoma Cerebellar haemangioblastoma Phaeochromocytoma

Question 44

Risk of renal cysts in Von Hippel-Lindau syndrome

Answer 44

Risk of transformation to renal cell cancer