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78 Cards in this Set
- Front
- Back
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what is another name for the posterior pituitary
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neurohypophysis, bc hormones released directly from neuron endings into the circulation
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where are the hormones made for the post pituitary
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from MAGNAcellular neurons in supraoptic and PV nucleus
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what is the pathway from the hypothalamus to post pit called?
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hypothalmo-neurohypophseal tract
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where are the hormones released from the phyothalmo neurophypophyseal tract?
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directly into the bloodstream in the capillary bed in the inferior hypophyseal artery
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What are the 2 hormones released from post pit?
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oxytocin and vasopressin
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what are the 2 ways to induce the release of oxytocin?
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tactile stimuli from the suckling infant and pressure on the cervix or uterine wall during labor
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what is the tract that the stimuli for oxytocin travel down?
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spinohypothalamic
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what are the 3 actions of oxytocin?
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causes release of milk or enhances contraction of uterine wall during labor, and contractions of uterine myometrium and smooth muscles of male and female reproductive tract
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what is the one sympathetic pathway to activate release of oxytocin?
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sensory input from F or M repro tracts during sexual activity
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where does vasopressin act and for what purpose
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on the V2 receptors of renal distal tubular epithelium to incr reabsorption of water and electrolytes
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what are the 3 stimuli for release of vasopressin
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increased plasma osmolarity, decreased blood pressure, decreased blood oxygen
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How does incr plasma osmolarity induce release of vasopressin? (what neurons does it act on and how)
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acts on magnacellular neurons intrisically and extrinsically. Intrinsic: the MC neurons have osmopreceptors in their plasma membranes and intitiate synthesis and release. Extrinsic: MC neurons recieve afferent input from osmo-sensitive neurons in the organum vasculosum of lamina terminalis
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how does decr blood pressure induce release of vasopression
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angiotensin II activates subfornical neuron that send to MC neurons
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how does decr in blood O2 induce release of vasopressin (i.e. neuropathway)
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carotid an aortic bodies -->MC neurons via vagus and glossopharyngeal nerves -->relay to solitary nucleus
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what are the 2 disorders associated with vasopressin
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diabetes insipidus and syndrome of inappropriate AVP secretion (SIADH)
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what is the neurological problem with diabetes insipidus
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insufficient secretion to normal physiologic stimuli or failur of kidney to respond to the vasopressin
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what is the problem with SIADH
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could be trauma, encephalitis, acute psychosis, durg induced (vincristine, general anesthetics, antidepressents), ectopic (tumors)
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what controls the release of ant pit hormones
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hypothalamic releasing hormones
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in what nuclei are the hormones synthesized for ant pituitary
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parvocellular nueron in arcuate, PV, periventricular and supraoptic nuclei
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how many types of hormones can parvocellular neurons produce and secrete?
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more than one at a time
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what is the pathway of PV neurons
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tubero-infundibular tract
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what is the capillary bed that the tubero-infundibular tract drains into?
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superior hypophyseal artery
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what controls the secretion of ant pit hormones?
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diurnal rhythms
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what mediates the ultra-short feedback loop?
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hypothalamic releasing factor limit their own release by an autocrine effect on hypothalamus
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what mediates the short loop feedback?
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inhibition of releasing factor secretion by pituitary hormones
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what mediates the direct long loop feedback
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peripheral hormone inhibition of pituitary secretion
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what mediates the indirect long loop feedback
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inhibition of the hypothalamic secretion of releasing factors
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what are the 6 hormones secreted by the ant pituitary
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FLAT PG = follicle stimulating hormone, Leutinizing hormone, adrenocoroticoprotpin, thyroid stimulatin hormone, prolactin, growth hormone
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what secretes growth hormones
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somatotrophs
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what controls release of GH?
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GHRH
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where is GHRH concentrated (which hypoth nucleus?
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arcuate nucleus
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what inhibits the release of GHRH?
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somatostatin (ultra short loop), GH (short loop), and IGH (indirect long loop)
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what neurons secrete prolactin
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pituitary lactotrophs
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what controls the release of prolactin?
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dopamine (esp from arcuate and PV nuclei)
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how does dopamine work to control release of prolactin?
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actson D2 receptors to incr adenyl cylcase in lactotorphs and inhibit prolactin release
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what is the short loop feedback involved with prolactin?
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inr plasma prolactin induces incr levels of dopamine in arcuate and PV nuclei
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what secretes LH and FSH
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gonadotrophs
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what controls release of LH and FSH
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LHRH (conc in arcuate nucleus)
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what is the indirect long loop regulation of LHRH
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estrogen(F) and testosterone (M)
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what secretes TSH?
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thyrotrophs
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what contols the release of TSH?
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TRH (concentrated in paraventric nucleus)
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what is the direct long loop inhibtion for TSH
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T4, T3 inhibit TSH production at the pituitary
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what is the indrect long loop inhibition for TSH
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T4 and T3 inhibit TSH production at the hypothalamus
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what produces ACTH
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corticotrophs
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what controls release of ACTH
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CRH (and it is released in pulses with a peak at 4am)
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what is the direct long loop inhibition of ACTH
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cortisol inhibits release of ACTH
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what is the indirect long loop inhibition of ACTH
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cortisol inhibits release of CRH
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what is a huge stimulant for release of CRH and thus, ACTH?
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STRESS!
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what disorders are associated with GH?
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acromegaly and gigantism and dwarfism
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what disorders are associated with prolactin
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hyperprolactinemia, prolactin deficiency
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what disorders are associated with LH and FSH
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hypogonadotropic hypogonadism and hypergonadotropism
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what disorders are associated with TSH
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hypothyroidism and hyperthyroidism
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what disorders are associated with ACTH
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hypercortisolemia (cushing's disease)
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how would the blood tests show for someone with ectopic cushings syndrome
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low CRF, and high ACTH but no pituitary tumor
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how would blood tests look for pituitary cushing's syndrome
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low CRF, ACTH, corisol would be incr
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how would blood test show for adrenal cushing's syndrome
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low ACTH and low CRF
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def: acute phase response
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the cascade of behavioral responses induced by activation of the immune system
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def: psychoneuroimmunology
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the influence of brain activity on immunity
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what is the purpose of the acute phase response?
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to reallocate energy resources and to induce an environment hostile to invading pathogens
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what are the 4 primary mediators of the acute phase response?
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IL-1beta, IL-6, the interferons and tumor necrosis factor and hormones
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describe the pathway of effect that IL-1beta has on CNS, etc
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IL-1beta --> COX2 -->PGE2 -->EP4--> incr in cAMP (in preoptic-anterior and PV hypothalamic nuclei and a2 brainstem nucleus) --> fever, activated neuroendocrine and hepatic acute phase protein synthesis
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does IL-1beta cross into the CNS to activate the acute phase response?
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NO. IL-1beta can't cross blood brain barrier, but PGE2 can.
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what nuclei in hypothalamus induce fever?
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preoptic anterior, paraventricular, and a2 brainstem nucleus
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which nuclei induce somnolence, anorexia and irritability associated with acute phase response?
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nucleus tractus solitarius to the hypothalamus, hippocampus and amygdala
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what activates IL-6 and what is the purpose of IL-6?
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IL-1beta activates IL-6 to prolong the maintenance of the acute phase response
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what turns off the acute phase response?
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plasma corisol levels suppress COX2 and IL-6R expression
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what is the importance of interferons and TNF?
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respond to sickness of viral and neoplastic illness
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what produces the hormones for the acute phase response? what are the hormones involved?
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lymphoid cells produce: GH, prolactin, ACTH, TSH, beta-endorphin and enkephalins
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what are the pathways/neuro-systems involved in psychoneuroimmunology
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neuroendocrine system and symp and parasymp systems
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what is involved with EUstress
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LOW STRESS, therefore good immune system! includes: increased humoral immunity, incr resistence to cancer and infection, incr Cell mediated immunity, leukocyte redepolyment promotes innate immunity and homeostasis
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what is involved with DIstress
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HIGH STRESS, therefore bad immunity. Involves: suppression of leukocyte trafficking and innate immunity, decr cell mediated and humoral immunity, incr incidence of cancer and infection, disruption of homeostasis
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def: lateral inhibition
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sharpening of the nervous system via suppression of certain neurons (so only the best neurons are proliferating); cortisol induces a LOT of lateral inhibition (to focus immune system)
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is the neuro/adenohypophysis considered a direct or indirect type of release?
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direct, because the hormones go directly to their end organ (ant pituitary = indirect)
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what hormones of the ant pituitary are concentrated in arcuate nucleus
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FSH, LH, GH, prolactin
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what hormones of the post pituitary are concentrated in paraventricular nucleus
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ATP!!
ACTH, TSH, prolactin |
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What nucleus induces fever?
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poah
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what 2 things do cAMP cause?
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fever (in the poah), increase in PKA (causes gene expression of IL-6, CRF and acute phase proteins)
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what does CRF increase?
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ACTH-->incr corticosteroids-->stops production of COX-2 in the endothelial cells
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