FINAL: endocrine & dermatology Flashcards
what is gigantism?
when epiphysial plates of long bones are still open (before puberty), and there is excessive GH
when does acromegaly occur?
result of GH production after the closure of epiphysial plates (post-puberty age). After sexual maturation and long bone can’t grow anymore, it increases the size of internal organs, distorts bone (fascial, nasal, jaw, toes) that have no epiphysial plates
There are a number of disorders that may increase the pituitary’s GH output in gigantism and acromegaly, what is the most common?
most commonly it involves a GH producing tumor called PITUTITARY ADENOMA (tumor), derived from distinct type of cell (somatotrophs)
acromegaly most commonly affects who?
middle age adults
what are complicatios of acromegaly?
compression of optic chiasm leading to loss of vision in outer visual fileds (bi-temporal hemianopia); increased palmar seating and sebum production; severe HA; arthiritis and carpal tunnel syndrome; enlarged heart; hypertension; diabetes mellitus; HT and KD failure
what are some tx options for acromegaly?
Endonasal Transphenoidal surgery; Trans-sphenodial surgery; medication or radiostatic neurosurgery; prolactinoma
what is Congential Hyothyroidism (CHT)?
thyroid hormone deficinecy present at birth
what is Cretinism?
outdated medical term for Congenital Hypothyroidsim: if this condition is untreated for several months after birth, it can lead to growth failure and permanent mental retardation - Creatinism. TX consists of daily dose of oral application of thyroid hormone (thyroxine)
what is presentation of hypothyroidism?
pituitary pressing on active
what is the primary, secondary, and tiertiary order of endocrine system?
III: Releasing Hormone from Hypothamalmus ; II: Stimulating Hormone from Anterior Pituitary (also called Adenohypophysis); I: periphery gland
what is Negative Feedback Regulation of Hormone Release in the Hypothalamic-Pituitary axis?
once peripheral glands fulfilled “their obligations” to secrete normal amount of primiary/peripheral hormones, they will feedback to secondary level (anterior pituitary) and to tertiary level (hypothalamus) to stop further “push” for production of corresponding primiary hormones. Opposite is also true: if peripheral glands do not secrete minimally normal amount of primary hormones, empty receptors of corresponding trophs (cells of anterior pituitary) and hypothhalamic nuclei will activate production of releasing and tropic/stimulating factors to encourage primary glands to “secrete better”
if there are problems with the primary level (the peripheral glands) of the endocrine system, it looks like?
if perhperial glands are “lazy” (deficient state, for instance Thyroid organ not producing enough T3 or T4), the anterior pituitary and hypothalamus will increase secretions of Stimulating Hormones and Releasing Factors correspondingly. When peripheral hormones are in excess, the further production of stimulating and releasing factors / hormones will be inhibited. [so hormones moving in OPPOSITE direction]
If there are problems with Secondary Level (overproduction or underprodution of Stimulating Hormones) due to pituitary tumors (could be secreting excessively or just inactively pressing on “troph” cells), the behavior of primary glands will be?
the primiary glands will mimick their “commanders in chiefs” [so hormones move in SAME direction]. Meaning the primary glands will secrete the same order as their “boss”, which means the negative feedback stopped working as the secondary level exhibits pathological condition
If lab tests HIGH Cortisol Level and LOW ACTH level, possible dx is?
tumor in adrenal gland (in primary level, bc hormones are opposite)
If lab tests HIGH cortisol level with HIGH ACTH level, dx is?
Tumor in the anterior pituitary (secondary level, bc hormones move in same direction)
in Secondary Level: Anterior Pituitary, what are corresponding hormones?
Thyrotrophs - thyroid stimulating hormones; Corticotrophs - ACTH (adenocortiocotrophic hormones) & MSH; Gonadotrophs - LH & FSH; Somatotrophs - GH
In Negative Feedback Inhibition, if the hormone cortisol of peripheral gland binds ot its receptor in cells in the hypothalamus and anteior pituitary, and has the effect of ,
inhibiting secretion of Tropic hormones (corticoropin releasing hormones CRH in this case) and Adrenocorticotropic Hormone (ACTH). LESS CRH secretion leads to LESS ACTH secretion, which leads to less stimulation of cortisol secretion by cells of zona fasciculata of adrenal cortex
what is usefullness of negative feedback inhibition?
that it results in Hormonal Homeostasis - the maintenance of hromone levesl within particular appropriate physiological range. *For example: if adrenal gland is damaged, this will decrease secretion of cortisol. There wil be decrease in degree of negative feedback inhibition on Hypothalamus and Anterior Pituitary. Resulting in MORE CRH and ACTH secretion. More ACTH will stimulate the remaining adrenal tissue to grow and sevrete more cortisol, brining cortisol back up to normal daily level of secretion.
if there is problems with the anterior pituitary on the second level of the endocrine system, then it is ALWAYS?
Adenoma - tumor of the brain (it can even be benign)
what is the most common cause of hyperthyroidism?
Grave’s Disease
what is pathogenesis of Graves’ disease?
it is an autoimmune reaction on unknown interrupting immune tolerance factor (smoking?, pregnancy?, etc). It results in production of self anti-bodies (IgG), over-stimulating TSH receptors of thyroid gland. As a result, thyroid gland secretes excessive amounts of T3 and T4. Natural TSH will be eventually supressed by auto-antibodies. TSH is LOW, and T3/T4 are oth HIGH (mimics primary profile of endocrine condition)
