Endocrine System

Front 1

Pituitary Gland

Back 1

aka HYPOPHYSIS

resides within the sella turcica, in the sphenoid bone.

Front 2

Adenohypophysis

Back 2

anterior lobe of pituitary gland, makes up 80%

cells divided into 3 groups of equal #: stainable and unstainable cells (CHROMOPHOBE CELLS). The cytoplasmic granules of the stainable cells are called acidophilic or basophilic.

Hormone-producing cells: corticotropes, lactotropes, somatotropes, thyrotropes, gonadotropes.

Front 3

Neurohypophysis

Back 3

Posterior lobe of the hypophysis, makes up 20%.

Composed of pituicytes, a type of glial cell without secretory function and unmyelinated nerve fibers containing ADH and oxytocin.

Front 4

Define hypopituitarism.

Back 4

THe deficient secretion of 1ore more of the hormones produced by the pituitary.

Front 5

Panhypopituitarism:

Back 5

total failure of pituitary function occurs.

Front 6

Define pituitary adenomas.

Back 6

Benign neoplasms of the anterior lobe of the pituitary.

Usually associated with excess secretion of pituitary hormones.

Microadenomas: <10 mm in diameter; don't produce symptoms.

Macroadenomas: >10 mm in diameter; cause both local symptoms + systemic manifestations.

Front 7

Lactotrope Adenomas

Back 7

Aka prolactinomas. These are composed of cells that secrete prolactin.

Hyperprolactinemia is the most commo nendocrinopathy that is associated with pitutiary adenomas.

Front 8

Somatotrope Adenomas

Back 8

These secrete GH and produce striking bodily changes.

Gigantism, acromegaly
Patients develop coarse facial features, overgrowth of mandible/maxilla with spaces between upper incisor teeth, thickened nose, enlarged hands/feet, increased hat size.

Increased incidence of C-v, cerebrovascular, respiratory deaths.

1/3 have hypertension, diabetes occurs in 20%, hypercalciuria and renal stones in 1/5.

Front 9

Gigantism

Back 9

results when a somatotrope adenoma arises in a child or adolescent before the epiphyses close.

Front 10

Acromegaly

Back 10

Results when a somatotrope adenoma becomes functional after the epiphyses of the long bones have fused and adult height has been achieved.

Front 11

Corticotrope Adenomas

Back 11

These secrete corticotrophin, which inturn induces adrenocortical hypersecretion to produce Cushing Disease.

Front 12

Central diabetes insipidus

Back 12

Due to deficiency of vasopression (ADH) -- posterior pituitary!!

Inability to concentrate urine (so it very dilute) and consequent chronic water diuresis, thirst, and polydipsia (excessive thirst).

Front 13

Nontoxic Goiter

Back 13

This refers to an enlargement of the thyroid that is not associated with functional, inflammatory, or neoplastic alterations = euthryoid (normal thyroid gland).

Simple, colloid, or multinodular goiter.

Women:men = 8:1

Diffuse (early stages) or multinodular (chronic)nontoxic goiters.

Front 14

Toxic Multinodular goiter

Back 14

When patients with nontoxic goiter develop hyperthyroidism.

Front 15

Hypothyroidism.

Back 15

Refers to the clinical manifestations of thyroid hormone deficiency. Can be the consequence of:

defective synthesis of thyroid hormone
inadequate function of thyroid parenchyma
inadequate secretion of TSH by the pituitary or of TRH by the hypothalamus.

Front 16

Hypothyroidism in Adults

Back 16

Insidious symptoms: tiredness, lethargy, sensitivity to cold, inability to concentrate.

Skin: proteoglycans accumulate in the ECM, binding water and resulting in a peculiar form of edema called MYXEDEMA.

Boggy facies, puffy eyelids, edema of hands/feets, enlarged tongue, Pale, cool skin.

Front 17

Myxedema madness

Back 17

paranoid ideation or depression and severe agitation.

Front 18

Myxedema heart

Back 18

dilated heart and a pericardial effusion. heart is flabby and shows interstitial edema and swelling of the myocytes.

Front 19

Myxedema megacolon:

Back 19

GI tract of hypothyroidism in adults: constipation due to decreased peristalsis.

Front 20

CRETINISM

Back 20

Congenital Hypothyroidism.
Girls:boys = 2:1
90% of cases result from thyroid dysgenesis (developmental defects of the thyroid).

Infants are apathetic and sluggish, large abdomen and shows an umbilical hernia, body temp <35C

mental retardation, stunted growth.

if no thyroid hormone replacement therapy --> mentally retarded dwarfs.

Front 21

Primary hypothyroidism

Back 21

When the case of thyroid failure is uncertain.

3/4 of patients have circulating anitbodies to thyroid antigens.

Front 22

Goitrous hypothyroidism

Back 22

Endemic goiter: goitrous hypothyroidism of dietary iodine deficiency.

Endemic cretinism: congenital hypothyroidism that occurs in areas of endemic goiter.

Goiter induced by antithyroid agents: LITHIUM.

Front 23

Hyperthyroidism

Back 23

Refers to the clinical conseuqence of excessive circulating thyroid hormone.

Signs/symptoms reflect a hyper-metabolic state of the target tissues.

Front 24

Graves Disease

Back 24

An autoimmune disorder that is characteirzed by diffuse goiter, hyperthyroidism, and exophthalmos.

Front 25

Define thyroiditis.

Back 25

Refers to a heterogeneous group of inflammatory disorders of the thyroid gland, including those that are caused by autoimmune mechanisms and infectious agents.

Front 26

Hashimoto Thyroiditis

Back 26

(Lymphocytic Thyroiditis)
Is an autoimmune disease that is characterized by circulating antibodies to thyroid antigens adn features that are suggestive of cell-mediated immunity to thyroid tissue.

In regions where supplies of iodine are adequate, Hashimoto thyroiditis is the most common cause of goitrous hypothyroidism.

Front 27

Subacute Thyroiditis

Back 27

(Granulomatous or Giant Cell Thyroiditis)
An infrequent, self-limited viral infection of the thyroid that is characterized by granulomatous inflammation.

Typically occurs after upper respiratory tract infections.

Front 28

Riedel Thyroiditis

Back 28

A rare disease that is characterized by dense fibrosis of the thyroid.

Involves extrathyroidal soft tissues.

Front 29

Hypoparathyroidism.

Back 29

Usually results from decreased secretion of parathyroid hormone and occasionally from end-organ sensitivity to the hormone.

Most common cause: inadvertent surgical resection of the parathyroids.

Idiopathic
Familial
Pseudo

Front 30

Primary hyperparathyroidism

Back 30

Is the syndrome caused by excessive secretion of PTH as a result of intrinsic parathyroid disease.

Parathyroid Adenoma = 80%
Primary Parathyroid Hyperplasia = 15%
Parathyroid Carcinoma = 1%

Hypercalcemia and hypophosphatemia
-osteitis fibrosa cystica
-renal colic
-mental changes
-peptic ulcer disease
-chronic pancreatitis
-hypertension

Front 31

Secondary hyperparathyroidism

Back 31

Refers to excess secretion of PTH as a response to chronic hypocalcemia.

Encountered in patients with chronic renail failure.

Renal osteodystrophy: osseous manifestations

Front 32

Congenital Adrenal Hyperplasia

Back 32

CAH is a syndrome in which deficient synthesis of corticosteroids results in the unopposed action of corticotropin, and hence, adrenal hyperplasia.

>90% of the cases represent an inborn deficiency of 21-hydroxylase, or P450c2I

Front 33

Simple Virilizing CAH

Back 33

Female infants: pseudohermaphroditism (sexual ambiguity), fused labia, enlarged clitoris, urogenital sinus.

Male infants: no abnormalities of sexual rogans; sexual precocity (maturity), closure of epiphyses and stunted growth.

Adult women: infertile
Adult men: may or may not be fertile.

Front 34

Salt-Wasting CAH

Back 34

Synthesis of aldosterone impaired --> hyponatremia, hyperkalemia, dehydration, hypotension, increased renin secretion.

Front 35

Adrenocortical Insufficiency

Back 35

Deficient production of adrenocortical hormones can result from:
-destruction of the adrenal gland
-dysfunction of the pituitary or hypothalamus
-intake of corticosteroids as treatment for chronic inflammatory diseases.

Front 36

Addison Disease

Back 36

aka Primary Chronic Adrenal Insufficiency

A fatal, wasting disorder that is caused by failure of adrenocortical secretion.

Autoimmune adrenalitis is responsible for 75% of cases.

>90% of the adrenal gland must be destroyed before symptoms appear.

Weakness, weight loss, GI symptoms, HYPOTENSION (RULE), electrolyte disturbances, hyperpigmentation, marked personality changes.

Front 37

Acute Adrenal Insufficiency (Adrenal crisis)

Back 37

A life-threatening medical emergency that reflects a sudden loss of adrenocortical function.

occurs in 3 settings:
1. abrupt withdrawal of of corticosteroid therapy
2. the stress of infection or surgery.
3. waterhouse-friderichsen syndrome: acute, bilateral, hemorrhagic infarction of the adrenal cortex.

Front 38

Adrenal Hyperfunction

Back 38

excess secretion of corticosteroids occurs in the context of adrenal hyperplasia or neoplasia.

2 forms:
hypercortisolism = cushing syndrome
hyperaldosteronism = conn syndrome.

Front 39

Cushing disease

Back 39

aka Corticotropin-DEPENDENT adrenal hyperfunction

With few exceptions, adrenal hyperplasia is secondary to chronic stimulation by corticotropin.

Women 5x>males

bilateral, DIFFUSE (75%) or NODULAR (25) hyperplasia of the adrenal glands.

Front 40

Cushing disease results from 1 of the following:

Back 40

1. primary hypersecretion of corticotropin by the pituitary

2. ectopic production of corticotropin by a nonpituitary tumor (cancer of lung).

3. inappropriate secretion of CRH (corticotropin-releasing hormone).

Front 41

Corticotropin-Independent Adrenal Hyperfunction.

Back 41

A functional neoplasm of the adrenal cortex is a well-documented cause of Cushing syndrome.

-adrenal adenoma: encapsulated, firm, yellow mass; exhibit clear, lipid-laden cells that are arranged in sheets/nests.

Front 42

Most common cause of Cushing syndrome

Back 42

long-term administration of corticosteroids.

corticosteroid treatment of a vairety of immnologic and inflammatory diseases

Front 43

Clinical features of cushing syndrome

Back 43

obesity: moon face, buffalo hump (neck), trunk, abdomen.

skin is atrophic and there is loss of subcutaneous fat.

icnreased bone resorption --> osteoporosis.

Hypertension.

Females show increased facial hair, acne, oligomenorrhea.
Men: erectile dysfunction and decreased libido.

Hyperinsulinemia, diabetes mellitus

Psychological: irritability, emotional lability, depression, paranoia.

Front 44

Conn Syndrome

Back 44

aka Primary Aldosteronism.

Conn syndrome, which is characterized by hypertension and hypokalemia, is produced by inappropriate secretion of aldosterone by an adrenal adenoma or hyperplastic adrenal glands.