23 Parathyroid ANATOMY AND PHYSIOLOGY

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Where are the superior parathyroids located?

Medial to recurrent laryngeal nerves, more anterior, below inferior thyroid artery

Intra-thyroid, mediastinal, near tracheoesophageal groove

In the tail of the thymus

Lateral to recurrent laryngeal nerves, posterior surface of superior portion of gland, above inferior thyroid artery (correct)

Which artery supplies blood to both superior and inferior parathyroid glands?

Superior thyroid artery

Brachiocephalic trunk

Inferior thyroid artery (correct)

Carotid artery

What is the most common ectopic site for inferior parathyroids?

Intra-thyroid

Near tracheoesophageal groove

Mediastinal

In the tail of the thymus (correct)

Which pharyngeal pouch is associated with the inferior parathyroids?

3rd pharyngeal pouch Signup and view all the answers

Which of the following conditions is characterized by a defect in the PTH receptor in the distal convoluted tubule of the kidney, leading to increased resorption of calcium?

Familial hypercalcemic hypocalciuria Signup and view all the answers

What is the treatment for familial hypercalcemic hypocalciuria?

No treatment is required Signup and view all the answers

Which condition results from a defect in the PTH receptor in the kidney, making it unresponsive to PTH?

Pseudohypoparathyroidism Signup and view all the answers

In which location is lung most commonly affected by metastases in parathyroid cancer?

Lung Signup and view all the answers

What is the 5-year survival rate for parathyroid cancer?

50% Signup and view all the answers

Which gene mutation is associated with MEN I syndrome?

MENIN gene Signup and view all the answers

What is the primary cause of death in patients with MEN IIa and MEN IIb syndromes?

Medullary thyroid carcinoma Signup and view all the answers

Which condition is the most common cause of outpatient hypercalcemia?

Hyperparathyroidism Signup and view all the answers

What is the mechanism of action of Mithramycin in treating hypercalcemia?

Inhibits osteoclasts Signup and view all the answers

Which type of cancer can release PTHrP, leading to hypercalcemia?

Breast cancer Signup and view all the answers

What is the primary cause of hypercalcemic crisis?

Hyperparathyroidism Signup and view all the answers

What is the prevalence of pheochromocytoma in MEN IIa syndrome?

Nearly all patients Signup and view all the answers

What is the primary role of parathyroid hormone (PTH) in the body?

Increasing renal calcium reabsorption Signup and view all the answers

What is the most common cause of hypoparathyroidism?

Previous thyroid surgery Signup and view all the answers

Which hormone decreases serum calcium levels?

Calcitonin Signup and view all the answers

What is the characteristic bone lesion seen in hyperparathyroidism?

Osteitis fibrosa cystica (brown tumors) Signup and view all the answers

What are the symptoms of primary hyperparathyroidism?

Muscle weakness, nephrolithiasis, and depression Signup and view all the answers

What diagnostic workup is recommended for primary hyperparathyroidism?

Serum protein electrophoresis and 24-hour urinary calcium determination Signup and view all the answers

What is the treatment for parathyroid adenoma?

Total parathyroidectomy with autotransplantation Signup and view all the answers

What is the management approach for missing parathyroid glands during surgery?

Checking inferiorly in thymus tissue for ectopic location Signup and view all the answers

What is the most common location for a missing parathyroid gland during surgery?

Intra-thyroid Signup and view all the answers

What can cause hypocalcemia postoperatively after parathyroid surgery?

Bone hunger or failure of parathyroid remnant/graft Signup and view all the answers

What is the preferred imaging modality for locating overactive parathyroid glands?

Sestamibi scan Signup and view all the answers

What is the management approach for secondary hyperparathyroidism in patients with renal failure?

Control diet phosphate and use phosphate-binding gel (sevelamer chloride) Signup and view all the answers