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26 Cards in this Set
- Front
- Back
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What are the major circulatory system afferents received by hypothalamus and what are their funxns?
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1-Ant pituitary hormones & hormones of target tissues (estradiol, thyroxine, etc) give negative feedback. 2- hormones affecting apetite: -=Glc, Insulin, Leptin; +=gherlin. 3-Sodium and AgtsnII (receptors in SFO & OVLT. 4- PG E2
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What are neural afferents to the hypothalamus and what is their funxn?
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retina goes to suprachiasmatic nucleus for circ. rhythm. Fornix leads to hippocampus (en route to mamillary body) for memory consolidation. Amygdala for fear. Medial forebrain bundle in lateral zone: going to Nuc accumbens for pleasure, reward; going to Solitary nucleus for visceral information
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What are the main hypophysiotropic (releasing/inhibiting) hormones of the hypothalamus and where are they produced?
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Corticotropin RH produced in PARAventricular nuc, Thyrotropin RH, Gonadotropin RH, Growth hormone RH, somatostatin (inhbt GH), DA (inhbt Prl) all made in PERIventriular and arcuate nuclei. They are dumbed into median eminence as result of APs
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What is the pathway of control of blood pressure by the hypothalamus?
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In response to decreased BP & blood vol. the SFO, MnPO, & OVLT are activated thus stimulating Paraventricular and Supraoptic nuclei to release Vasopressin causing increased resorption of water
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What things are the lateral hypothalamic area involved in?
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wakefulness and autonomic nervous system regulation
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What is the route of autonomic nervous system regulation in the hypothalamus?
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Axons from Paraventricular nucleus and lateral area of hypothal project via medial forebrain bundle to brainstem and spinal cord.
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What parts of the brain regulate wakefulness and how?
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axons from the lateral hypothalamus release hyopcretin in the tuberomamillary nucleus which projects histaminergic neurons via mid forebrain bundle to cortex to promote wakefullness. Lateral preoptic nucleus projects inhibitory neurons to tuberomamillary nucleus to promote sleepfullness.
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What are signs of anterior pituitary lesions and what are symptoms of each?
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1-Hypothyroidism: puffy face, drynes, hoarse speech, low BP, cold intol. 2-Hypoadrenalism: fatigue, hyoptension, infxns. 3- low GH in kids= growth retard, hypoglycemia, low FSH, LH in kids=hypogonads, delayed pub. 4- hyperprolactinemia and low gonadotropins: decreased libido, infertility, galactorrhea, erectile dys(M), amenorrhea (W)
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What is diabetes insipitus?
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Low vasopressin prodxn in Post Pituitary or lack of response to VP in kidney. Symptoms are peeing and drinking a lot
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What is syndrome of inappropriate ADH secretion? Causes?
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Too much ADH causing water reabsorption and hyponaturemia w/ normal or increased plasma volume. Caused by tumors, drugs, lung dx, CNS disorders. Signs are confusion, stupor, siezures, coma
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What are all the pathways that run thru the medial forebrain bundle?
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1. afferent connections w/ nucleus accumbens for reward. 2. afferent connections w/ solitary nucleus for visceral info. 3-ANS regulatioin thru hypothalamospinal tract. 4- histaminergic fibers from tuberomamillary nuc to cortex for wakefulness regulation
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What does a posterior pituitary lesion cause?
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central diabetes insipidus
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What are some homeostatic disorders associated w/ hypothalamus lesions?
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Temperature: hyper/hypothermia, poikilothermia. Weight: increased apetite, obesity, emaciation. Sleep
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What is diencephalic syndrome? what associated with?
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emaciation despite good apetite. Usually from hypothalamic tumor. People can get rage attacks too and aterograde amnesia
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What is the mechanism of thirst from cellular dehydration?
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blood osmo changes sensed by osmoreceptors located in hepatic portal vein which activate vagal fibers to send input to NTS. NTS does: 1- conxn to PVN and SON to activate vasopressin release. 2- conxn to OVLT, SFO, MnPO which connect to PVN and SON to activate VP release and descending circuits
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What is the mechanism of the renin-angiotensin system? What does angiotensin II work on?
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renin released from juxuloglom cells of kidney takes AGtogen-- AGtn I which goes to AGtn II. AGtnII released NE from symp nerves to cause vasoconstxn, aldosterone release from adrenal cortex causing Na reaborsop, and Ang II gets to OVLT and SFO to activate drinking, ADH secrtn, SNS activation
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What hormones are subject to short loop feedback?
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Prolactin will inhibit its own release. Growth hormone will also inhibit its release
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What hormones are subject to long-loop feedback?
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T3,T4 cause inhibition of TRH and cortisol inhibits release of CFR. GH inhibited by insulin-like growth factor-1
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If a person has high TSH rather then T3/T4 what does that indicate?
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hypothyroidism
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What is an endocrine diagnosis for menopause?
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FSH elevation
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What hormones are subject to positive feedback?
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estradiol causes release of LH, oxytocin causes more release of itself
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What is responsible for childhood or adult onset of GH deficinecy?
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GHRH
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What happens in polycystic ovarian syndrome?
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abnormal feedback of gonadotropins resulting in infertility
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What does hyperprolactinemia inhibit?
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HPG axis
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Cushing syndrome? what causes it and symptoms?
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hypersection of ACTH from pituitary tumor
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What changes happen w/ high osmolality? low blood volume? What can inhibit these?
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Hyperosmolality: osmo receptors in liver portal vein send signal to NTS which then goes to SFO, PVN to cause release of VP. They also go to OVLT, MnPO, SFO to activate drinking as well as go to SFO, PVN. Low blood volume sensed in baroreceptors sending signals to NTS to dothe same except it also activates SNS. Caffeine and alcohol inhibit these, they are diauretics
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