Exam 2 (Endocrine)

Question 1

What are the peripheral effects of the thyroid function?

Answer 1

• Heat generation
• stimulates ATP formation in mitochondria
• influences flux of ions
• stimulates metabolic processes (basal metabolic rate, protein synthesis regulation of protein, fat & carb metabolism

Question 2

Thyroid hormone regulates the metabolism of ___, ___, & ___.

Answer 2

protein, fat & carbs

Question 3

The thyroid sympathetic fibers pass through what to get to the thyroid?

Answer 3

• Cardiac periaterial plexus &
• superior & inferior thyroid plexus

Question 4

What are the 2 main blood supply sources for the thyroid?

Answer 4

• The superior thyroid artery ( branch of the external carotid)
• inferior thyroid artery ( branch of the subclavian artery)

Question 5

Decreased T3 levels can be due to?

Answer 5

Hypothyroidism,
cirrhosis,
uremia &
malnutrition

Question 6

Decreased T4 levels can be due to?

Answer 6

Hypothyroidism,
androgens,
salicylates,
sulphonamides

Question 7

What are some anti-thyroid drugs?

Answer 7

• PTU (Propylthiouracil),
• methimazole,
• carbimazole (inhibit the action of peroxidase enzyme)

Question 8

Why are glucocorticoids given in hyperthyroidism?

Answer 8

They inhibit conversion from T4 to T3 & decrease the release of thyroid hormone

Question 9

How does radioactive iodine work?

Answer 9

Destroys the follicular cells

Question 10

How is a temporary hypoparathyroidism treated?

Answer 10

• High dose calcium,
• calcitrol (Vitamin D)

Question 11

What post-op lab can predict hypocalcemia?

Answer 11

Low PTH

Question 12

What is myxedema & S/S?

Answer 12

• Severe form of hypothyroidism
• S/S: stupor, coma, hypotension, hyponatremia, hypoventilation, hypothermia

Question 13

Where does a pheochromocytoma arise from?

Answer 13

Chromaffin cells of the adrenal medulla.

Question 14

What is a paraganglioma?

Answer 14

An extra-adrenal pheochromocytoma

Question 15

What is stored in the adrenal medulla?

Answer 15

• 80% epinephrine &
• 20% norepinephrine

Question 16

Epi & Norepi derive from?

Answer 16

Tyrosine

Question 17

Alpha-2 receptor stimulation leads to?

Answer 17

• Inhibits release of NE, vasoconstriction.
• Stimulates cognition

Question 18

Stimulation of which receptor causes glycogenolysis & insulin secretion?

Answer 18

Beta-2

Question 19

Stimulation of which receptor causes sodium reabsorption?

Answer 19

Alpha-1

Question 20

A pheochromocytoma is also called what?

Answer 20

The 10% tumor

Question 21

What are the symptoms of pheochromocytomas?

Answer 21

HA, diaphoresis, N/V, anxiety

Question 22

What do we look at when testing for pheochromocytoma?

Answer 22

Plasma Metanephrines

Question 23

What metabolites are elevated in a 24hr urine test in a Pt with a Pheo?

Answer 23

Metanephrine, normetanephrine & vanillylmandelic acid

Question 24

When is phenoxybenzamine initiated?

Answer 24

1-3 weeks before resection

Question 25

What is another drug besides phenoxybenzamine?

Answer 25

Doxazosin

Question 26

What does a medication plan for a pheo look like?

Answer 26

- Start alpha-1 med and wait for adequate blockade until starting a beta antagonist. - Starting beta antagonist too early may lead to HTN crisis & pulmonary edema

Question 27

What is the best VA for pheochromocytoma, & why?

Answer 27

Isoflurane d/t it being the least cardiac depressant

Question 28

What is generally avoided in a parturient with a pheochromocytoma?

Answer 28

Vaginal delivery as it can lead to HTN crisis

Question 29

The parathyroid primarily consists of ____.

Answer 29

Chief cells

Question 30

What effect does lithium have on the parathyroid?

Answer 30

- Increases PTH secretion & - decreases cell sensitivity to calcium.

Question 31

What effect does vitamin D have on the parathyroid?

Answer 31

Decreases PTH secretion

Question 32

PTH is what kind of amino acid?

Answer 32

An 84 polypeptide amino acid

Question 33

What is the effect of PTH on bones?

Answer 33

Increase activity of osteoclasts causing calcium release from bones

Question 34

What are the effects of PTH on the kidneys?

Answer 34

- Increase calcium reabsorption from urine. - Increases urinary phosphate excretion. - Increases renal production of 1,25 (OH) D (Vitamin D3), which causes increased GI absorption of calcium

Question 35

What population is most at risk for hyperparathyroidism?

Answer 35

Age early 50’s & Female

Question 36

What is the most common cause of outpatient hypercalcemia?

Answer 36

Primary hyperparathyroidism

Question 37

What is the major cause of primary hyperparathyroidism?

Answer 37

85% caused by single adenoma

Question 38

What are the 3 causes of primary hyperparathyroidism?

Answer 38

- Single adenoma, - diffuse hyperplasia, - multiple adenomas

Question 39

What are the S/S of hyperparathyroidism?

Answer 39

- Stones, bones, groans, moans - (renal, skeletal, abdominal, cardiovascular, psychiatric & neuromuscular)

Question 40

What are the neuropsychiatric S/S of hyperparathyroidism?

Answer 40

- Easy fatigue. - Depression. - Inability to concentrate. - Memory problems. - Proximal myopathy (symmetric weakness in muscles close to body’s center)

Question 41

What does bisphosphonate do?

Answer 41

It lowers calcium but may increase PTH

Question 42

What does Cinacalcet do?

Answer 42

- It lowers calcium but only modestly lowers PTH. - It does not decrease calcium excretion.

Question 43

What is the downside to parathyroid imaging?

Answer 43

All are very poor at multi-gland disease

Question 44

What is done for a patient who presents for parathyroidectomy and has an increased calcium level?

Answer 44

Dilute calcium with NS and maybe give loop diuretic.

Question 45

What kind of ventilation is avoided intraop for a Pt undergoing parathyroidectomy & why?

Answer 45

- Hypoventilation - acidosis can lead to increased ionized calcium → cardiac arrhythmias

Question 46

How is a parathyroid crisis managed?

Answer 46

- Hydration to dilute calcium. - Diuresis with loop diuretics. - Glucocorticoids, - calcitonin, - dialysis

Question 47

What is the half-life of PTH?

Answer 47

~ 4mins

Question 48

When are PTH levels drawn?

Answer 48

- At baseline before incision. - During manipulation of the suspected gland. - 5, 10, 20 mins after gland excision.

Question 49

What is indicative that all offending glands have been removed?

Answer 49

A PTH decline of >50% from baseline

Question 50

What innervates the larynx sensory above the vocal cords?

Answer 50

Internal branch of the SLN

Question 51

What innervates the larynx sensory below the vocal cords?

Answer 51

Recurrent laryngeal nerve

Question 52

What & where is released in response to increased calcium & how does it work?

Answer 52

- Calcitonin from the parafollicular cells. - Inhibits osteoclastic activity in the bones & inhibits renal tubular cell reabsorption of calcium.