PSYCH 330 1st Edition Exam #6 Study Guide What does the hypothalamus facilitate? What parts of the brain does the hypothalamus communicate with?Hormones and the Brainmotivated behavior directed by the hypothalamus, hypothalamus stimulates different systems depending on where the hypothalamus itself is stimulatedhormones travel long distanceshormones responsible for homeostasis, reproductive functions, stressresponse(cortisol) hypothalamus>pituitary>pituitary releases hormone>thathormone travels through the bloodstream to a target(gonads,etc)hormones differ by structure, steroid hormones are made from cholesterol, fat soluble so they can travels through the organ/blood brain barrier, peptide hormonesDNA>proteinRegulatory and non regulatory behaviorregulatory=keeping balance, if you deviate your body wants to bring you back to homeostasis temperature regulationeating/drinking -salt consumptionwaste eliminationnon regulatorynot for basic needs or dependent on for homeostasisfrontal cortex and limbic systems are upstream systems trickling down to the hypothalamus influenced by external stimuli, i.e sexual behavior, parental behavior,food preference aggression, curiosity, readinginteractions with environment, influenced by social cueseating for homeostasis you need digestive cues to initiate, can have cognitive cuessomething looks good or smells goodHomeostasisset point=optimal value or your comfort leveldetector=when your body goes above or below threshold it is detected; receptors are detectors -peptide like CCK/ghrelin is released to tell brain im hungry(ghrelin, green light to eat),or i’m full(CCK, inhibitory, red light to stop)lateral hypothalamus is away from the midline and initiates green light, forsatietythe ventromedial hypothalamussuppresses, gives red light; if the ventromedial is damaged you overeatcorrectional mechanism=gets you back to set pointLearningcognitive influences result in learned associations, smell something bad/learned from getting sick from food that it is badamygdala responsible for taste aversioninferior prefrontal cortex takes cues from your olfactory bulb(smell)Drinkingfor thirst>osmotic, to correct cellular dehydration which happens if the solutes draw too much outfor replacementvolumetric, lose water through sweat and blood needs to be replacedLecture#10What defines stress? What are the origins of fear?Hormones and Stressstressorarousing, anything that disrupts homeostasis -stress response=calming, short/long termcortisolregulates slower stress response, negative feedback turned on and off by theHPA axis hippocampus tends to be smaller in people with depression because cortisolis misregulated & cortisol levels climb too high killing neurons in hippocampusdepressionslower return to baseline, higher base cortisol levelPTSDsensitive firing of HPA axis, emotionally learned, response is larger, negativefeedback double times brings it higher than a regular persons baseline then falls to abaseline that is lower than a regular persons baselinedepressionslower return to baseline, higher base cortisol levelstress>hypothalmus releases CRF to the bottom of the brain>CRF hits axons in thepituitary> pituitary releases 2nd hormone, ACTH>ACTH travels to adrenal glands->adrenal glands release cortisol accordinglyCRF releasing cells are in the cortex/amygdala HPA axis takes awhilethe sympathetic nervous system is responsible for your immediate reaction to stress sympathetic nervous system(fight/flight) is a neural pathway epinephrine(adrenaline)responsible for what you feel first, increases blood flow/heartrate, sweatmeasure sweat through your galvanic skin responseyour behavioral stress responses are learned and thus become automaticEmotioninferred state that is context dependentsubjective feeling inferred from you autonomic or hormonal responses stress handled by hypothalamus/brain stememotion/interpretation, fear, handled by amygdala/hippocampus(limbic system) if damaged you could lose fearfear can be innate/learned Amygdalasee things>occipital lobe>from thalamus to amygdalaamygdala is a collection of nuclei, subdivided, gets input from all sensory systems(thalamus/senses)projects to brainstem/hypothalamus/prefrontal cortexsmell has a direct path to the amygdala which is why smells can remind you of thingsPrefrontal Cortexthoughts/plans actions, anticipation damaging prefrontal cortex alterspersonality prefrontal deals with rewardstied to the brain all