Parathyroid Disorders

Question 1

PTH acts on

Answer 1

Bone, kidneys, and intestines to increase blood calcium levels

Question 2

The absence of parathyroid glands is

Answer 2

Incompatible with life

Question 3

The parathyroid gland has two types of cells

Answer 3

Chief cells and oxyphil cells

Question 4

What is the main function of chief cells?

Answer 4

Manufacturing, storing and rapidly releasing PTH in response to alterations of blood calcium levels

Question 5

Chief cells stain slightly

Answer 5

Eosinophilic

Question 6

Chief cells contain secretory granules that contain

Answer 6

PTH

Question 7

Which cells are inactive chief cells?

Answer 7

Oxyphil cells

Question 8

Oxyphil cells may take on a water-clear apperance due to the presence of

Answer 8

Cytoplasmic glycogen

Question 9

Oxyphil cells tend to be slightly larger than chief cells, have acidophilic cytoplasm and are tightly packed with

Answer 9

Mitochondria

Question 10

Oxyphil cells have secretory granules that are slightly sparse or

Answer 10

Absent

Question 11

As people get older, what increases in the parathyroid gland?

Answer 11

Adipose tissue and oxyphil cells

Question 12

Wht are the normal serum calcium levels?

Answer 12

8.5 to 10.5

Question 13

What effect does PTH have on bone?

Answer 13

Inhibits osteoblast activity and stimulates osteoclast activity aka increases bone resorption

Question 14

What effect does PTH have on the kidneys?

Answer 14

PTH increases calcium reabsorption within the distal convoluted tubules and blocks phosphate reabsorption in the proximal tubules

Question 15

PTH stimulates the production of what vitamin?

Answer 15

D within the proximal tubules

Question 16

What effect does PTH have on the GI system?

Answer 16

Increased calcium reabsorption

Question 17

What is primary hyperparathyroidism?

Answer 17

Autonomous overproduction of PTH. Usually secondary to adenoma or hyperplasia of parathyroid tissue

Question 18

What is secondary hyperparathyroidism?

Answer 18

Hypocalcemia triggers a compensatory increased secretion of PTH (example: kidney disease)

Question 19

What is tertiary hyperparathyroidism?

Answer 19

Consequence of prolonged hypocalcemia even after it is corrected. Even we we correct the hypocalcemia, PTH doesnt go down when it is supposed to.

Question 20

Hyperparathyroidism is an important cause of?

Answer 20

Hypercalcemia

Question 21

Primary hyperparathyroidism is a common endocrine disorder secondary to

Answer 21

Adenomas 85 to 95%
Primary hyperplasia (diffuse or nodular) 5-10%
Parathyroid carcinoma

Question 22

What is the most common cause of primary hyperparathyroidism?

Answer 22

Pararhyroid adenoma

Question 23

MEN-1 mutations are associated with?

Answer 23

Parathyroid adenoma

Question 24

Overexpression of cyclin D1 secondary to cyclin D1 gene inversions are associated with

Answer 24

Parathyroid adenomas

Question 25

What are the symptoms of primary hyperparathyroidism?

Answer 25

Painful bones, renal stones, abdominal groans, and psychic moans

Question 26

What are other clinical symptoms of primary parathyroidism?

Answer 26

Bone pain secondary to fractures, constipation, nausea, peptic ulcers, pancreatitis, gallstones, depression, lethargy, eventually seizures, myalgias, weakness, fatigue, aortic or mitral valve calcifications

Question 27

parathyroid adenomas are almost always

Answer 27

Solitary -may be present at an ectopic site (mediastinum)

Question 28

Parathyroid adenomas are mostly composed of

Answer 28

Polygonal chief cells with small centrally placed nuclei

Question 29

the growth of parathyroid carcinoma is limited to

Answer 29

1 gland

Question 30

What is the only criteria for parathyroid carcinoma?

Answer 30

Invasion of surrounding tissues and metastasis

Question 31

In parathyroid carcinoma we can appreciate

Answer 31

Bands of fibrous tissue between the nests of carcinoma cells

Question 32

What is the leading cause of secondary hyperparathyroidism?

Answer 32

Renal failure

Question 33

What are some other secondary causes of secondary hyperparathyroidism?

Answer 33

Deficient dietary calcium, steatorrhea, vitamin D deficiency

Question 34

Decreased phosphate excretion is also associated with

Answer 34

Secondary hyperparathyroidism

Question 35

What is the main cause of acquired hypoparathyroidism?

Answer 35

Surgically acquired

Question 36

Autoimmune hypoparathyroidism is associated with

Answer 36

Autoimmune polyendocrine syndrome type 1 along with chronic mucocutaneous candidiasis and primary adrenal insufficiency

Question 37

Autosomal dominant hypoparathyroidism is due to

Answer 37

Gain of function mutations in the calcium sensing receptor gene (CASR)

Question 38

Heighened calcium sensing suppresses what?

Answer 38

PTH which result in hypocalcemia and hypercalciuria

Question 39

Familial isolated hypoparathyroidism (the autosomal dominant version) is associated with

Answer 39

A mutation in the gene encoding PTH precursor peptide

Question 40

The autosomal recessive verison of FIH is associated with?

Answer 40

A loss of function mutation in the transcription factor gene glial cells missing-2 (GCM2)

Question 41

What is the deletion in Di George syndrome?

Answer 41

22q11.2 deletion

Question 42

Di George syndrome leads to

Answer 42

Congenital malformations of the heart, parathyroid and thymus

Question 43

What is the main manifestation of hypocalcemia?

Answer 43

Tetany

Question 44

Tetany is characterized by

Answer 44

Neuromuscular irritability

Question 45

What other symptoms can be seen in hypoparathyroidism?

Answer 45

Perioral numbness Paraesthesias of the distal extremities and carpopedal spasm Life-threatening laryngospasm Generalized seizures

Question 46

What are some classic findings on hypoparathyroidism?

Answer 46

Chvostek sign- tapping along the facial nerve induces contractions of the muscles of the eye, mouth or nose Trousseau sign- carpal spasms produced by occlusion of the circulation to the forearm and hand with a blood pressure cuff for several minutes

Question 47

Hypoparathyroidism can induce

Answer 47

Mental status changes

Question 48

Hypoparathyroidi can induce intracranial manifestations like

Answer 48

Calcifications of the basal ganglia, parkinsonian-like movement disorders, increased ICP with resultant papilledema

Question 49

Hypoparathyroidism can result in

Answer 49

Calcification of the lens and cataract formation

Question 50

What cardiovascular problems can someone with hypoparathyroidism have?

Answer 50

Prolongation of the QT interval

Question 51

What dental abnormalities can be seen in hypoparathyroidism?

Answer 51

Dental hypoplasia, failure of eruption, defective enamel and root formation, abraded carious teeth