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72 Cards in this Set
- Front
- Back
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name the five cell types in the Anterior pituitary
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Somatotrophs
Lactotrophs (mammotrophs) Corticotrophs Thyrotrophs Gonadotrophs |
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Somatorophs produce ______ hormone
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growth hormone (GH
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Somatotrophs are acidophilic cells constitute ______ of all the hormone producing cells in the anterior pituitary
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half
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Lactotrophs (mammotrophs)
produce _______. |
prolactin
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Lactotrophs are acidophilic cells secrete prolactin, which is essential for ______.
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lactation
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Corticotrophs are ____philic cells
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basophillic
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Corticotrophs produce:
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adrenocorticotropic hormone (ACTH), pro-opiomelanocortin, melanocyte stimulating hormone (MSH), endorphins, and lipotropin...
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Thyrotrophs are pale _____philic cells
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baso
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Tryrotrophs produce
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thyroid stimulating hormone (TSH)...
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Gonadotrophs are ______philic cells
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basophillic
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Gonadotrophs produce
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both follicle stimulating hormone (FSH) and luteinizing hormone (LH)...
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FSH stimulates
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the formation of graafian follicle in the ovary
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LH induces:
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ovulation and the formation of corpora lutea in the ovary...
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Posterior Pituitary aka
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neurohypophysis,
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Posterior pituitary consists of
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modified glial cells (termed pituicytes) and axonal processes extending from nerve cell bodies
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oxytocin and vasopressin, are stored:
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through the pituitary stalk to the posterior lobe
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Posterior pituitary is derived embryologically from an
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outpouching of the floor of the third ventricle, which grows downward alongside the anterior lobe...the neuroectoderm...
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herring bodies are formed from:
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from neuroectoderm as an extension of the developing diencephalon...
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the pituitary has ______ circulation
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dual
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Prolactinomas
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most frequent type of hyperfunctioning pituitary adenoma
30% |
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increased serum levels of prolactin, or prolacintemia cause:
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amenorrhea, galactorrhea, loss of libido, and infertility.
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the diagnosis of an adenoma is made more readily in women or men?
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women, 20 to 40
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this tumor underlies almost a ______ of cases of amenorrhea...
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quarter
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macroadenoma
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= prolactin levels greater than 350...
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microadenoma
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= prolactin levels between 200 and 300...
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br______ suppresses prolactin secretion
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bromocriptine
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dopamine ______ prolactin
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inhibits
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physiologic hyperprolactinemia occurs in p______
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pregnancy
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serum prolactin levels increase throughout pregnancy, reaching a peak at ______.
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delivery
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prolactin levels are also elevated by ______ stimulation
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nipple
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prolactin levels are also elevated
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as a response to many types of stress...
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pathologic hyperprolactinemia can also result from ______ hyperplasia
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lactotroph
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interference with normal dopamine inhibition of prolactin secretion.
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pathologic hyperprolactinemia
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stalk effect
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any mass in the suprasellar comparment may disturb the normal inhibitory influence of the hypothalamus on prolactin secretion, resulting in hyperprolactinemia
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dopamine receptor antagonists
can cause |
hyperprolactinemia
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...prolactinomas are treated with ______, a dopamine receptor agonist, which causes the lesions to diminish in size...
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bromocriptine
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Growth Hormone Adenomas of the Pituitary
GH secreting tumors: |
second most common type of functioning pituitary adenoma...
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growth hormone synthesis is predominately regulated by hypothalamic
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GHRH (growth hormone releasing hormone),
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growth hormone synthesis pulsatile secretion is predominantly regulated by hypothalamic s______.
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somatostatin
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persistent hypersecretion of GH stimulates:
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the hepatic secretion of insulin like growth factor I (IGF-I), which causes many of the clinical manifestations.
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if the somatotrophic adenoma appears in children before the epiphyses have closed, the elevated levels of GH result in g______.
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gigantism
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if the increased levels of GH are present after closure of the epiphyses, patients dvevelop ______.
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acromegaly
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Corticotroph Cell Adenomas at diagnosis
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usually small microadenomas at the time of
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Corticotroph Cell Adenomas
these tumors are ______cphilic or chromophobic and stain positively with periodic acid schiff (PAS) stains b/c of the presence of carbohydrate in the ACTH precursor molecule |
basicophillic
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excess production of ACTH by the corticotroph adenoma leads excess production of ACTH by the corticotroph adenoma leads to:
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adrenal hypersecretion of cortisol and the development of hypercortisolism (also know as cushing syndrome)...
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hypopituitarism refers to
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decreased secretion of pituitary hormones, which can result from diseases of the hypothalamus or of the pituitary
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hypofunction of the anterior pituitary occurs when approximately ______% of the parenchyma is lost or absent...
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75%
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hypopituitarism result of
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may be congenital or the a variety of acquired abnormalities that are intrinsic to the pituitary...
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most cases of hypofunction arise from ______ processes directly involving the anterior pituitary
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destructive
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destructive processes examples:
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tumors, ischemic necrosis of the pituitary, and the empty sella syndrome, although other mechanisms hae been identified...
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Sheehan's syndrome, also known as _______ pituitary necrosis,
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postpartum pituitary necrosis,
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Sheehan's syndrome cause
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results from the sudden infarction of the anterior lobe of the pituitary..
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Sheehan's syndrome can occur with obstetric complications, such as ______ or ______...
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hemorrhage or shock
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the pituitary gland normally ______ in size during pregnancy
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doubles
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hypo______during delivery decreases blood flow and may result in infarction of the anterior pituitary...
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hypovolemia
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Sheehan's syndrome produces symptoms of ______.
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hypopituitarism
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hypopituitarism...the initial sign is cessation of ______.
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lactation
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hypopituitarism may be followed by secondary amenorrhea due to the loss of ______tropins.
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gonadotropins
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other signs of hypopituitarism include:
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hypothyroidism and decreased functioning of the adrenal gland...
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hypopituitarism not an emergency b/c other ______ hormones still keep working...
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endocrine
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ADH deficiency causes
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diabetes insipidus,
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diabetes insipidus
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excessive urination (polyuria) owing to an inability of the kidney to resorb water properly from the urine...
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ADH excess causes resorption of excessive amounts of free water, resulting in hypo______
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natremia
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most frequent causes of SIADH include
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the secretion of ectopic ADH by malignant neoplasms (particularly small cell carcinomas of the lung), non-neoplastic diseases of the lung, and local injury to the hypothalamus or posterior pituitary (or both)....
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clinical manifestations of SIADH are dominated by
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hyponatremia, cerbral edema, and resultant neurologic dysfunction
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(SIADH)
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Syndrome of Inappropriate ADH
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Syndrome of Inappropriate ADH
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SIADH
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Craniopharyngiomas
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derived from vestigial remnants of rathke pouch...
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Craniopharyngiomas describe
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slow growing tumors account for 1-5% of intracranial tumors; some of these lesions arise within the sella, but most are suprasellar...
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Craniopharyngiomas
children usually come to clinical attention b/c of |
endocrine deficiencies such as growth retardation,
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Craniopharyngiomas
adults usually present |
in the visual disturbances...bitemporal heminopsia...
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pituitary hormonal deficiencies, including diabetes insipidous, are common/uncommon.
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common
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