What can cause abnormalities in the endocrine function?
1. faulty feedback system
2. Dysfunction of the gland
3. altered metabolism of hormones
4. production of hormones from nonendocrine tissue
Target cells may fail to respond because:
1. cell surface receptor associated disorders
2. intracellular disorders
3. circulating inhibitors
What are the two common disorders of the posterior pituitary ?
1. Syndrome of inappropriate ADH secretion: (SIADH) is caharacterized by abnormal high ADH secretion
2. Diabetes Insipidus : is characterized by abnormally low ADH secretion
Diabetes Insipidus :
may be neurogenic (insufficient amounts of ADH) or nephrogenic (caused by inadequate amounts of ADH).
Its prinicle clinical features are polyuria and polydipsia
can be primary (dysfunction of the pituitary) or secondary (dysfunction of the hypothalamus). Primary can result from a pituitary tumor, trauma, infections, stroke, or surgical removal.
Pituitary Adenoma :
if expanding can cause both neurologic and secretory effects. Pressure from expanding tuomor causes hyposecretion of cells, dysfunction of optic chiasma (leading to visual disturbances) and dysfunction of the hypothalamus and some cranial nerves.
Hypersecretion of growth hormone (GH):
causes acromegaly where the secretion becomes high and unpredictable. Pituitary adenomas are the most common cause.
result in glactorrhea, hirsutism, amaenorrhea, hypogonadism, osteopenia
is a general condition in which elevated thyroid hormone (TH) levels cause greater than normal physiologic responses. The condition can be caused by a variety of specific diseases each of which have its own pathophysiology and course of treatment.
most common form of hyperthyroidism
is caused by an autoimmune mechanism that overrides normal mechanisms for control of TH secretion and is characterized by thyrotoxicosis, opthalmopathy, and circulating thyroid stimulating hormone.
is caused by deficient production of TH by the thuroid gland. Secondary is the result of a hypothalmic or pituitary dysfunction. Symptoms depend on the degree of TH deficiency. Manifestations include decreased energy metabolism and decrease heat production and myxedema.
is associated with infiltration or fibrosis of the thyroid, circulating thyroid antibodies, and gradual loss of thyroid function. It occurs in those individuals with gentic susceptibility to an autoimmune mechanism that causes thyroid damage and eventual hypothyroidism.
is a sign of hypothyroidism caused by alterations in connective tissure with water binding proteins that leads to edema and thicked mucosa
which may be primary or secondary and is characterized by greater than normal secretion of PTH.
defined by abnormally low PTH and is caused by surgery, autoimmunity, or genetics
Diabetes Mellitus :
is a group of disorders charcterized by glucose intolerance, chronic hyperglycemia and disturbances of carbs, proteins and fat metabolism.
there are two different types.
Type 1 Diabetes Mellitus:
is characterized by loss of beta cells, islet cell antibody, lack of insulin, and excess of glucagon.
seems to be caused by a gradual process of autoimmune desturction of beta cells in gentically susceptible individuals.