Exam #3: Endocrine Disorders

Question 1

With Iodide Transport Defects (ITD)…

• What is the status of iodide?
• What is the status of T4/T3?
• What is the status of TRH?
• What is the status of TSH?

Answer 1

• Low iodide
• Low T4/T3

Lack of negative feedback…

• High TRH
• High TSH

Question 2

With Grave’s Disease…

• What is the status of T4/T3?
• What is the status of TRH?
• What is the status of TSH?

Answer 2

• High T4/T3

Increased negative feedback…

• Low TRH
• Low TSH

Question 3

Low uptake of iodide causes what condition?

Answer 3

Hypothyroidism

Question 4

High uptake of iodide causes what condition?

Answer 4

Hyperthyroidism

Question 5

What condition involves deficiency of iodide due to low dietary intake? Is this hypo- or hyperthyroidism?

Answer 5

Iodide Transport Defects (ITD)

- Hypothyroidism

Question 6

What condition involves autoantibodies bind to TSH receptor and stimulate thyroid gland (act like TSH)? Is this hypo- or hyperthyroidism?

Answer 6

Grave’s Disease

- Hyperthyroidism

Question 7

What is another name for Conn’s Syndrome? What is the cause?

Answer 7

Primary Hyperaldosteronism

- Aldosterone-secreting tumor

Question 8

What is another name for Primary Hyperaldosteronism? What is the cause?

Answer 8

Conn’s Syndrome

- Aldosterone-secreting tumor

Question 9

What four findings are seen with Conn’s Syndrome/Primary Hyperaldosteronism?

Answer 9

• HTN
• Hypokalemia
• Alkalosis
• Hypernatremia

Question 10

What three steroids are LOW with 17alpha-hydroxylase deficiency?

Answer 10

• Cortisol
• Androgens
• Aldosterone

Question 11

Why is aldosterone low with 17alpha-hydroxylase deficiency?

Answer 11

HTN → NO renin secretion

- RAAS not activated = low aldosterone

Question 12

What is another name for Addison’s Disease? What is the cause?

Answer 12

Primary Adrenocortical Insufficiency

- Autoimmune destruction of adrenal gland

Question 13

What is another name for Primary Adrenocortical Insufficiency? What is the cause?

Answer 13

Addison’s Disease

- Autoimmune destruction of adrenal gland

Question 14

What is HIGH with Addison’s Disease/Primary Adrenocortical Insufficiency? What three findings are LOW?

Answer 14

HIGH: ACTH

- LOW: aldosterone, cortisol, androgens

Question 15

How does low aldosterone affect BP? How does high aldosterone affect BP?

Answer 15

• Low aldosterone: hypotension

- High aldosterone: hypertension

Question 16

How does low aldosterone affect K+? How does high aldosterone affect K+?

Answer 16

• Low aldosterone: hyperkalemia

- High aldosterone: hypokalemia

Question 17

What condition involves hyperpigmentation of skin on elbows, knees, nipples, scars? What causes this, and which gene more specifically?

Answer 17

Addison’s Disease/Primary Adrenocortical Insufficiency

- Due to high ACTH, as alpha-MSH gene = melanocyte-stimulating

Question 18

Differentiate secondary and tertiary Adrenocortical Insufficiency. What three findings are LOW? Which is normal?

Answer 18

• Secondary: difficulty secreting ACTH
• Tertiary: low CRH so low ACTH

LOW ACTH, cortisol and androgens
- Normal aldosterone

Question 19

With Cushing’s, how can you differentiate syndrome from disease? What findings is HIGH for both?

Answer 19

• SYNDROME: low ACTH
• DISEASE: high ACTH

BOTH have high cortisol

Question 20

What four symptoms are seen with Cushing’s Syndrome/Disease?

Answer 20

• Hyperglycemia
• Abnormal fat distribution (buffalo hump, moon face)
• HTN
• Muscle atrophy

Question 21

What two steroids are LOW with 21beta-hydroxylase Deficiency?

Answer 21

• LOW aldosterone

- LOW cortisol

Question 22

Why is ACTH high with 21beta-hydroxylase Deficiency?

Answer 22

No cortisol feedback = HIGH ACTH

Question 23

What condition involves masculine features in child and adult females; newborn females can have male-type external genitalia?

Answer 23

21beta-hydroxylase Deficiency

Question 24

What causes Cleidocranial Dysplasia?

Answer 24

Mutation in Runx2 gene

- Critical in bone development and osteoblast differentiation

Question 25

What condition does a mutation in Runx2 gene cause?

Answer 25

Cleidocranial Dysplasia

Question 26

What condition involves PTH-secreting tumor?

Answer 26

Primary Hyperparathyroidism

Question 27

What three findings are seen with Primary Hyperparathyroidism?

Answer 27

- High PTH - Hypercalcemia - Hypophosphatemia

Question 28

Which two conditions present with HIGH calcium, phosphate, cAMP in urine?

Answer 28

- Primary Hyperparathyroidism | - Humoral Hypercalcemia (PTH-rp)

Question 29

What condition presents with +Trousseau’s sign?

Answer 29

Hypoparathyroidism

Question 30

What three findings are seen with Hypoparathyroidism?

Answer 30

- LOW PTH - Hypocalcemia - Hyperphosphatemia

Question 31

What condition involves cancer cells release PTH-rp (PTH-related peptide) → binds PTH receptors?

Answer 31

Humoral Hypercalcemia (PTH-rp)

Question 32

What three findings are seen with Humoral Hypercalcemia (PTH-rp)?

Answer 32

- LOW PTH - Hypercalcemia - Hypophosphatemia

Question 33

How can you differentiate Hypoparathyroidism from Humoral Hypercalcemia (PTH-rp) (2)? What do they both have in common?

Answer 33

BOTH: low PTH - Hypoparathyroidism: hypocalcemia and hyperphosphatemia - Humoral Hypercalcemia (PTH-rp): hypercalcemia and hypophosphatemia

Question 34

What condition involves mutated PTH receptor ONLY in bones and kidney?

Answer 34

Pseudohypoparathyroidism (Albright’s)

Question 35

What three findings are seen with Pseudohypoparathyroidism (Albright’s)?

Answer 35

- HIGH PTH - Hypocalcemia - Hyperphosphatemia

Question 36

With Rickets, what four findings are seen?

Answer 36

- LOW Vitamin D - LOW calcium - LOW phosphate - HIGH PTH

Question 37

What four chronic effects are seen with DM?

Answer 37

- Retinopathy - Neuropathy - Nephropathy - CVD

Question 38

What are two causes of excess insulin in DM (hypoglycemia)?

Answer 38

- Insulin overdose | - Reactive hypoglycemia

Question 39

What two findings cause further hyperglycemia in DM patients?

Answer 39

- Increased blood AAs | - Gluconeogenesis

Question 40

What condition involves excess GH in puberty?

Answer 40

Gigantism | - Affects long bone growth

Question 41

What condition involves excess GH in adulthood?

Answer 41

Acromegaly | - Growth NOT involving long bones (large hands/feet, larger viscera, etc.)

Question 42

What finding on OGTT is diagnostic for Acromegaly?

Answer 42

>1 ng/mL

Question 43

What are the five possible causes of dwarfism in puberty?

Answer 43

- Lack of GHRH - Pituitary insufficiency - GH receptor deficit (Laron Dwarfism) - IGF-1 deficit - Failure to produce IGF-BP3

Question 44

What is the cause of Laron Dwarfism?

Answer 44

GH receptor deficit