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Disorders of the endocrine system are due to...
hyposecretion or hypersecretion
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define hyposecretion
inadequate release of a hormone
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define hypersecretion
excessive release of a hormone
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Other than hypo or hypersecretion, what else can cause endocrine system disorders?
faulty hormone receptors, an inadequate number of receptors or defects in second -messenger systems
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Several disorders of the anterior pituitary involve ____
hGH
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What does hyposecretion of hGH do?
during the growth years it slows bone growth and the epiphyseal plates close before normal height is reached.
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What is the disorder that is caused by hyposecretion of hGH?
Pituitary Dwarfism
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What treatment is needed for pituitary dwarfism?
administration of hGH during childhood, before the epiphyseal plates close
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What is caused due to hypersecretion of hGH during childhood?
giantism
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What is hypersecretion of hGH during adulthood called?
acromegaly
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Because the epiphyseal plates are already closed, what bones are affected with acromegaly?
the bones of the hands, feet, cheeks, and jaws thicken and other tissues enlarge.
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Other than bones, what other tissues enlarge due to acromegaly?
eyelids, lips, tongue, and nose...and the skin thickens and develops furrows, especially on the forehead and soles
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What is the most common abnormality associated with dysfunction of the posterior pituitary?
diabetes insipidus
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What causes diabetes insipidis?
due to defects in antidiuretic hormone (ADH) receptors or an inability to secrete ADH usually caused by a brain tumor, head trauma or brain surgery that damages the posterior pituitary or the hypothalamus.
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In nephrogenic diabetes insipidus what happens?
te kidneys do not respond to ADH.
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Why wouldn't the kidneys respond to ADH to cause nephrogenic diabetes insipidus?
the ADH receptors may be nonfunctional or the kidneys may be damaged.
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What is a common symptom of both forms of DI?
excetion of large volumes of urine, with resulting dehydration and thirst. Bed wetting is common in afflicted children
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Can people die from DI?
Yes, because so much water is lost in the urine, they can die of dehydration if deprived of water for a day or so.
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How do you treat neurogenic DI?
hormone replacement, usually for life. Either sub Q injection or nasal spray application of ADH analogs. Restriction of salt in the diet and paradoxically the use of certain diuretic drugs.
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What affect all major body systems and are among the most common endocrine disorders?
thyroid gland disorders
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What is the hyposecretion of thyroid hormones that is present at birth, and has devastating consequences if not treated promptly?
congenital hypothyroidism
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What used to be called cretinism?
congenital hypothyroidism
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What condition can cause severe mental retardation and stunted bone growth?
congenital hypothyroidism
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How do they treat congenital hypothyroidism?
most states require testing of all newborns to ensure adequate thyroid function. If it exists, oral thyroid hormone treatment must be started soon after birth and continued for life.
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What is myxdema?
hypothyroidism during the adult years,
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Who does myxdema mostly affect?
females
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What is a hallmark symptom of myxdema?
edema...they also have a slow heart rate, low body temp, sensitivity to cold, dry hair and skin, muscular weakness, general lethargy and a tendency to gain weight easily....may be slow mentally, but not retarded
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How do we treat mxedema?
oral thyroid hormones to reduce symptoms
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What is the most common form of hyperthyroidism?
graves disease
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Who does graves disease affect more?
7 to 10 times more often in females than in males usually before age 40
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What is graves disease?
an autoimmune disorder in which the person produces antibodies that mimic the actionof thyroid stimulating hormone
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What is a sure sign of graves disease?
enlarged thyroid, which may be 2-3 times larger than normal
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What is exophthalmos/
a peculiar edema behind the eyes that causes the eyes to protrude...found in graves patients
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How do you treat graves disease?
surgical removal of part or all of the thyroid gland, the use of radioactive iodine to destroy thyroid tissue, and the use of antithyroid drugs to block synthesis of tyroid hormones
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What is a goiter?
an enlarged thyroid gland
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what is goiter associated with?
hyperthyroidism, hypothyroidism or euthyroidism
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what is euthyroidism?
normal secretion of thyroid hormone
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how do you treat goiter due to inadequate iodine intake?
give them iodine
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What is hypoparathyroidism?
too little parathyroid hormone that leads to a deficiency of blood Ca2+, which causes neurons and muscle fibers to depolarize and produce action potentials spontaneously.
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What causes twitches, spasms and tetany?
hypoparathyroidism
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What is the leading cause of hypoparathyroidism?
accidental damage to the parathyroid glands or to their blood supply during thyroidectomy surgery.
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What is hyperparathyroidism?
an elevated level of parathyroid hormone, most often due to a tumor of one of the parathyroid glands.
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What happens with an elevated level of PTH?
excessive resorption of bone matrix, raising the blood levels of calcium and phosphate ions and causing bones to become soft and easily fractured.
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What are some of the symptoms found in patients with hyperparathyroidism?
formation of kidney stones, fatigue, personality changes, and lethargy
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What causes cushings syndrome?
hypersecretion of cortisol by the adrenal cortex.
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What can cause hypersecretion of cortisol by the adrenal glands?
a tumor of the adrenal gland that secretes cortisol, or a tumor elsewhere that secretes adrenocorticotropic hormone, which in turn stimulates excessive secretion and redistribution of body fat
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What are some of the physical signs of cushings syndrome?
spindly arms and legs wit a rounded moon face, buffalo hump and pendulous (hanging) abdomen. Flushed facial skin, and the skin on the abdomen had stretch marks, easy blushing and slow wound healing
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What does an elevated level of cortisol cause?
hyperglycemia, osteoporosis, weakness, hypertension, increased susceptibility to infection, decreased resistance to stress, and mood swings.
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What causes addisons disease?
hyposecretion of glucocorticoids and aldosterone
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What are the majority cases of addisons disease?
autoimmune disorders in which antibodies cause adrenal cortex destruction or block binding of ACTH to its receptors.
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Other than autoimmune, what else can cause addisons disease?
pathogens such as the bacterium that causes TB also may cause adrenal cortex destruction
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Symptoms that don't usually show until 90% of the adrenal cortex is destroyed are:
mental lethargy, anorexia, nausea and vomiting, weight loass, hypoglycemia and potassium and decreased sodium in the blood, low blood pressure, dehydration, decreased cardiac output, arrhythmias and even cardiac arrest.
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What is a qunique symptom of skin in addisons disease?
A bronzed appearance that is often mistaken for a suntan.
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How do we treat addisons disease?
replacing glucocorticooids and mineralocorticoids and increasing sodium in the diet
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What are pheochromocytomas?
benign tumors of the chromaffin cells of the adrenal medulla
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What causes hypersecretion of epinephrine and NE?
phoechromocytomas
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What is the result of pheochromocytomas?
a prolonged version of the fight or flight response
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Why is diabetes mellitus the fourth leading cause of deathy by disease in the U.S.?
because of it's damage to the cardiovascular system
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What are the 3 "p's" in diabetes mellitus?
- polyuria, polydipsia and polyphagia
- extreme urine, extreme thirst and extreme eating
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Some synthetic hormones that block the receptors for some nautrally occurring hormones are available as ___
drugs
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What is an example of synthetic hormone that blocks the naturally occuring phenomonon, pregnancy?
RU486..The uterine conditions needed for nurturing an embryo are not maintained, embryonic development stops and the embryo is sloughed off along with the uterine lining.
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What hormones are effective when taken by mouth?
steroid hormones and thyroid hormones
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Why are steroid and thyroid hormones effective when taken orally?
they are not split apart during digestion and easily cross the intestinal lining because they are lipid soluble
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What hormones are not effective orally?
peptide and protein hormones like insuin because degestive enzymes destroy them by breaking their peptide bonds
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What causes beta cell burnout?
excess hGH which causes hyperglycemia...which stimulates the pancrease to secrete insulin continually...if it lasts for weeks or months, it causes beta cell burnout.
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What is beta cell burnout?
a greatly decreased capacity of pancreatic beta cells to synthesize and secrete insulin
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Excess secretion of hGH may have a ____ ____, that is it can cause diabetes mellitus
diabetogenic effect
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Why did midwives let a first born twin nurse years before OT was discovered?
to speed the birth of the second child...it stimulates the release of OT...during a single birth, it promotes expulsion of the placenta & helps the uterus regain its smaller size
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Why would we use OT sythetically?
to induce labor or to increase uterine tone and control hemorrhage just after giving birth
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What is congenital adrenal hyperplasia (CAH)?
a genetic disorder in which one or more enzymes needed for synthesis of cortisol are absent.
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What happens when cortisol is low?
ACTH secretion by the anterior pituatary is high due to lack of negative feedback inhibition..it then stimulates growth and secretory activity of the adrenal cortex.
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When precursor molecules accululate and some of these are weak androgens what can happen with testosterone?
the weak androgens can convert to testosterone
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What happens when weak androgens convert to testosterone?
virilism, or masculinization
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What happens to females with virilism?
growth of a beard, development of a deeper voice and a masculine distribution of body hair, growth of the clitoris so it may resemble a penis, atrophy of the breasts and increased muscularity that produces a masculine physique
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In males, how does virilism present?
the same as in females and are not easily diagnosed
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How do you treat virilism?
cortisol therapy which inhibits ACTH secretion and thus reduces production of adrenal androgens
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