endocrine

Question 1

Mechanisms of Hormone Alterations

Answer 1

Inappropriate Amounts of Hormone Delivered to Target Cell

Inappropriate Response by Target Cell

Inadequate Hormone Synthesis

1.Inadequate quantity of hormone precursors

2.Secretory cell unable to convert precursors to active hormone

1.Decrease in the number of receptors

2.Impaired receptor function

3.Presence of antibodies against specific receptors

Failure of Feedback Systems

Dysfunctional or Ectopic Hormones Intracellular Disorders
1.Inadequate biologically free hormone

2.Hormone degraded at an altered rate

3.Circulating inhibitors

4.Ectopic production of hormones

1.Inadequate synthesis of a second messenger

2.Intracellular enzymes or proteins are altered

Dysfunctional Delivery System
1.Inadequate blood supply

2.Inadequate carrier proteins

Question 2

alteration in hypothalamus

Answer 2

The most common cause of apparent hypothalamic dysfunction is interruption of the pituitary stalk. Such interruptions prevent hypothalamic hormones from reaching the pituitary gland

Question 3

syndrome of inappropriate ADH secretion (SIADH)

Answer 3

ADH release in the absence of normal physiologic stimuli from the pituitary gland cause water retention. fluid is reabsorbed in the kidney therefore dilutional hyponatremia, high urine osmolarity, high urine sodium concentration.

Question 4

symptoms of SIADH

Answer 4

related to hyponatremia
- thirst, fatigue, dulled sensorium
-vomiting, abd cramps
-lethargy, confusion, muscle twitching

related to water retention
-weight gain but peripheral edema is absent

Question 5

Diagnosis and management
of SIADH

Answer 5

(1) serum hypoosmolality and hyponatremia,

2) urine hyperosmolarity (i.e., urine osmolality is greater than expected for the concomitant serum osmolality)

(3) the absence of conditions that can alter volume status (e.g., adrenal or thyroid dysfunction, congestive heart failure, or renal insufficiency)

correct hyponatremia

Question 6

characteristic of Diabetes Insipidus

Answer 6

insufficient ADH activity, leading to polyuria (frequent urination) and polydipsia (frequent drinking)

Question 7

Neurologic Diabetes Insipidus ( central DI)

Answer 7

insufficient ADH secretion

due to lesion of the hypothalamus, pituitary stalk, or posterior pituitary interferes with ADH synthesis, transport, or release.

Traumatic brain injury
immunological
hereditary

Question 8

Nephrogenic DI

Answer 8

inadequate response of the renal tubules to ADH.

disease damage the renal tubules.

Drugs that induce reversible form of nephrogenic DI

lithium carbonate, colchicine, amphotericin B, loop diuretics, general anesthetics, and demeclocycline.

Question 9

Diseases that causes Nephrogenic DI

Answer 9

pyelonephritis, amyloidosis, destructive uropathies, and polycystic kidney disease.

Question 10

Diabetes Insipidus

Answer 10

partial to total inability to concentrate urine. Insufficient ADH activity causes excretion of large volumes of dilute urine, leading to increased plasma osmolality, serum hypernatremia

Question 11

diagnostic and management of DI

Answer 11

polyuria, polydipsia, hypernatremia

low urine specific gravity (<1.010), low urine osmolality (<200mOsm/kg),
high serum osmolality (300mOsm or more depending on water intake),

ontinued diuresis despite a serum sodium level of 145mEq/L or greater.

The diagnosis of DI
-two-step water deprivation testing in which urine output is maintained despite dehydration.

Question 12

compare and contrast SIADH and DI

Answer 12

Question 13

Hypopituitarism

Answer 13

absence of one or more anterior pituitary hormones or the complete failure of all anterior pituitary hormone functions.

Question 14

common cause of hypopituitarism

Answer 14

Pituitary infarction
(due to significant blood loss or hypovolemic shock.) lead to tissue damage, fibrosis

space-occupying lesions include pituitary adenomas or aneurysms, which can enlarge and compress the pituitary gland.

traumatic brain injury,

removal or destruction of the gland

infections (e.g., meningitis, syphilis, tuberculosis),

autoimmune hypophysitis,

drugs (e.g., bexarotene, carbamazepine, ipilimumab).

mutation of the prophet of pituitary transcription factor (PROP-1) gene,

Question 15

hormone release by the anterior pituitary gland

Answer 15

FLAT PeG

FH
LH
ACTH
TSH
Prolactin
GH

Question 16

Most common autoimmune Hypothyroid condition

Answer 16

Hashimoto thyroiditis

autoimmune

thyroid infiltration of T lymphocytes and follicular destruction

Question 17

Primary hyperthyroidism

Answer 17

results from thyroid gland dysfunction

Graves disease,
toxic multinodular goiter, toxic thyroid adenoma.

Question 18

Graves disease

Answer 18

B cell-mediated type 2 hypersensitivity reaction,

immune system produces antibodies - thyroid-stimulating immunoglobulins (TSI) or thyroid receptor antibodies (TRAb). bind to and activate TSH receptors on the surface of thyroid cells

leads to the stimulation and enlargement of the thyroid gland and excessive production of thyroid hormones (hyperthyroidism).

T cells infiltrate also observed in the the thyroid gland due to overall immune response.

Question 19

difference btw Graves disease,
toxic multinodular goiter, toxic thyroid adenoma.

Answer 19

Toxic multinodular goiter occurs when there are several hyperfunctioning nodules leading to hyperthyroidism. Unlike Graves disease, there is absence of an autoimmune stimulus. If only one big nodule is hyperfunctioning, it is termed toxic adenoma.

Question 20

GH and the anterior pituitary gland

Answer 20

Controlled by hypothalamic release of GHRH and growth inhibiting hormone (somatostatin). Ant pit release small pulsatile amount of GH each day.

GH acts on the Liver stimulates production of insulin-like growth factor 1 that promotes cell metabolism
GH acts on the muscle inc protein synthesis
GH slows carb utilization inc blood glucose and insulin
GH acts on the growth plate of the bones, inc osteoblast and growth
Hypoglycemia and increased concentration of amino acids in the blood stimulates GH release

Question 21

ACTH and the anterior pituitary gland.

Answer 21

Regulate the release of hormones by the anterior adrenal gland.

in response to signals from the hypothalamus CRH

ACTH stimulates the release of

Glucocorticoid - cortisol ,antiinflammatory, metabolic effect

Mineralocorticoids - aldosterone, influence electrolyte and fluid balance

(physiological, psychological stress) Hypoxia, hypoglycemia, hyperthermia, exercise, and cortisol insufficiency stimulate the release of ACTH

Question 22

Cushing disease

Answer 22

Cushing disease refers to excess endogenous secretion of ACTH

Overproduction ACTH by a primary pituitary adenoma (most common and can occur at any age)

Ectopic secreting ACTH by a nonpituitary tumor, such as a small cell carcinoma of the lung (more common in older adults)

ACTH dependent - high ACTH low CRH

Over secretion of cortisol due to Adrenal gland tumor

ACTH independent - low CRH low ACTH

Question 23

Cushing Syndrome

Answer 23

Cushing syndrome (chronic hypercortisolism) refers to the clinical manifestations resulting from chronic exposure to excess cortisol regardless of cause.

primary cause by exogenous glucocortioid medication

Question 24

Breast Cancer