Endocrine

Question 1

Causes of elevated or depressed hormone levels

Answer 1

Failure of feedback systems
Gland dysfunction
Gland is releasing too much or too little
Increased hormone degradation or inactivation
Ectopic hormone release
Secretory cells unable to obtain, produce, or convert hormone precursors

Question 2

Ways the target cell can fail

Answer 2

Not enough receptors on cell surface
Impaired receptor function
Antibodies produced against the receptors (Hashimoto’s thyroiditis)
Antibodies mimic hormone action
Unusual expression of receptor function (more genetic, or may occur in tumor cells)

Question 3

For someone to be diagnosed with SIADH, they must have

Answer 3

normal thyroid and adrenal function, because thyroid hormone and glucocorticoids are essential for free water clearance by the kidneys. Meaning, if these glands weren’t functioning, it would also cause water retention.

Question 4

The posterior pituitary makes

Answer 4

ADH and oxytocin

Question 5

Symptoms of SIADH

Answer 5

Causes water retention, hyponatremia, and hypoosmolarity

Question 6

Cause of SIADH

Answer 6

Hypersecretion of ADH, usually from an ectopic source (small cell lung carcinoma)

Question 7

Types of DI

Answer 7

1) Neurogenic
- Low ADH release from posterior pit
- tumors, hypophysectomy, head trauma

2) Nephrogenic
- Normal ADH levels, but the kidney fails to respond
- d/t drugs or diseases that damage the renal tubules

Either way, causes total or partial inability to concentrate urine, and people get pretty damn dehydrated

Question 8

The brain is able to autoregulate between these MAPs

Answer 8

50-150

Question 9

Causes of pituitary infarction

Answer 9

Sheehan syndrome (post-partum hemorrhage)
Hemorrhage
Shock

Question 10

Causes of anhypopituitarism

Answer 10

Usually due to a cell DESTROYING tumor (or by head trauma or infections)

Question 11

Panhypopituitarism causes a decrease in release of these hormones

Answer 11

ACTH
TSH
LH and FSH
GH

This causes hypothyroidism, low cortisol (unable to handle stressors), and depressed sex hormone production. Results in lethargy, weight gain, and loss of all sexual function.

Question 12

Hyperpituitarism cause and manifestations

Answer 12

Usually caused by a benign, slow-growing pituitary adenoma that compresses the pituitary.

S/S

• HA and fatigue***
• Visual changes***
• Hyposecretion of neighboring hormones.

Question 13

Usually, pituitary adenomas cause increased secretion of

Answer 13

GH and prolactin. Paradoxically, they will decrease the release of neighboring hormones

Question 14

Acromegaly

Answer 14

Caused by a GH secreting pituitary adenoma. Causes connective tissue proliferation, thickening of bones and articular cartilage, narrowing of joint spaces, coarse skin and hair, enlarged bones of the face, hands, and feet

Question 15

Are those with dwarfism able to reproduce?

Answer 15

Only about 1/3 of them.

2/3 will NOT develop sexually d/t the lack of GH.

Question 16

What is the most common form of hyperthyroidism?

Answer 16

Grave’s disease

Question 17

Patho of Grave’s disease

Answer 17

TSIs (thyroid stimulating immunoglobulins) bind to TSH receptors, causing continual cAMP production. All this stimulation will increase T3 and T4 levels and decrease TSH levels.

Question 18

TSIs have a (longer/shorter) half-life than TSH

Answer 18

Longer (12 hours). TSH is only about 1 hour.

Question 19

Should we check thyroid hormone levels before we take someone with thyroid problems back to the OR?

Answer 19

YES! We do no want hyperthyroidism during surgery!!

Question 20

Is exophthalmos reversible with treatment?

Answer 20

No :(

Question 21

Causes of hypothyroidism

Answer 21

1) Autoimmune (Hashimoto)
2) Lack of iodine
3) Idiopathic causes (deficiency of enzymes needed to make T3 and T4)
4) Thyroid resection
5) Radiation to the thyroid

Question 22

Treatment for hypothyroidism

Answer 22

Levothyroxine
Iodine (if the cause if iodine deficiency)

Question 23

Hashimoto’s thyroiditis

Answer 23

T cells become sensitized to thyroid antigens. Th cells tell CD8 cells to destroy the thyroid cells, and they also tell B cells to make plasma cells with antibodies that will bind to and inhibit TSH receptors (anti-TSH receptor antibodies)

Question 24

What is myxedema?

Answer 24

A severe form of hypothyroidism.
Causes chondroitin and hyaluronic acid to build up between the connective fibers of the skin, resulting in boggy edema, especially around the eyes, hands, and feet.

Also causes thickening of the tongue and laryngeal/pharyngeal mucus membranes.

Question 25

What type of intubation would we probably do if our patient’s voice is hoarse?

Answer 25

Awake intubation

Question 26

Cause of cretinism

Answer 26

Hypothyroidism in fetal life, early infancy or childhood. Caused by

1) Failure of thyroid gland to develop
2) Lack of thyroid hormone
3) Lack of iodine

TH is essential for embryonic development, especially for the brain. Causes MR if not treated

Question 27

What happens in cretinism?

Answer 27

Skeletal growth is stunted more than soft tissue growth

- Causes growth stunting, obesity, large tongue, etc.

Question 28

Two types of hyperparathyroidism

Answer 28

1) Primary
- Excess PTH release
- D/t adenoma or hyperplasia

2) Secondary
- High PTH due to chronic diseases that cause low calcium or high phosphate
- ESRD or malabsorption syndromes

Question 29

How does hypoparathyroidism cause hypocalcemia?

Answer 29

The osteoclasts become almost totally inactive and there is almost no tubular Ca++ reabsorption. This causes decreased Ca++ levels.

Question 30

What major thing does hypocalcemia put you at risk for??

Answer 30

Laryngospasm!

Question 31

Treatment for hypoparathyroidism

Answer 31

PTH and vitamin D

Question 32

Causes of Cushing’s Syndrome

Answer 32

1) Pituitary tumor (most common)
2) Adrenal tumor
3) Paraneoplastic (ACTH secretion from outside the pituitary like in small cell)
4) Iatrogenic (exogenous corticosteroid use)

Question 33

Cushing’s syndrome is usually caused by elevated levels of

Answer 33

ACTH from the pituitary (caused by microadenoma)

Question 34

Conn’s disease is usually caused by tumors located where?

Answer 34

Zona glomerulosa (part of the adrenal cortex where aldosterone is made)

Question 35

Fluid/electrolyte changes associated with Conn’s syndrome

Answer 35

Hypervolemia, hypernatremia, hypokalemia, and metabolic alkalosis.
Patient will be very fluid overloaded and hypertensive, but not edematous (due to the effects of sodium escape phenomenon).

Question 36

Causes of Addison’s disease (adrenocortical insufficiency)

Answer 36

1) Primary atrophy (autoimmune)
2) Injury to the adrenal cortex
Both cause a decrease of BOTH corticosteroids (glucocorticoids and mineralcorticoids)

Depletion of aldosterone: Hyponatremia, hypovolemia, hyperkalemia, mild acidosis, low BP and CO.

Depletion of cortisol: Low BG, decreased metabolic function, decreased ability to respond to stressors