Central Autonomic Control Flashcards
describe the neuronal autonomic input for taste
- special visceral afferents (taste) run in CN VII, IX and X and enter the brainstem and synapse in the nucleus of the solitary tract (solitary nucleus)
- second order neurons located in the solitary nucleus send their axons (ipsilaterally) to the ventromedial nucleus of the thalamus
- third order neurons located in the thalamus send their axons to the primary gustatory cortex in the insula region
describe the general visceral afferents (ex. pain fibers) pathway
- general visceral afferents are also carried in CN VII, IX and X and synpase in the solitary nucleus
- second order neurons synapse in the hypothalamus and in the parabrachial nucleus
- third order neurons synpase in the amygdala
describe input via circumventricular organs
- circumventricular organs of the forebrain (including the subfornical organ and the organum vasculosum of the lamina terminalis) lack a blood-brain barrier
- these organs respond to changes in electrolyte balance and other blood compounds
- projections originating in these circumventricular organs provide input to the hypothalamus where they regulate hypothalamic output
- ex: secretion of ADH
describe the insular cortex
- the insular cortex receives visceral pain sensations, temperature sensations and taste sensations via the thalamus
- it integrates these interoceptive inputs with emotions and controls autonomic output via the hypothalamus
describe the anterior cingulate cortex
- the anterior cingulate cortex forms the anterior portion of the limbic lobe
- it controls autonomic output via its connections with the insula, the prefrontal cortex, the amygdala, the hypothalamus and the brainstem
describe hypothalamic control of the anterior pituitary
- axons of the parvocellular neuroendocrine cells within some of the hypothalamic nuclei terminate in the primary capillary plexus of the superior hypophyseal artery of the infundibulum
- this pathway is called the tubero-infundibular tract
- within the primary capillary plexus, neuroendocrine substances enter the blood
- these act on endocrine cells (unlike the post. pituitary)
describe the hypothalamic control of the posterior pituitary
- some of the nuclei of the hypothalamus (paraventricular nucleus, supraoptic nucleus) contain magnocellular neuroendocrine cells
- these neurosecretory cells send axons to the PP (aka neurohypophysis) forming the supraoptico-hypophyseal tract
- inside the PP, the synaptic endings of these neuroendocrine cells release neurohormones into fenestrated capillaries originating from the inferior hypophyseal artery
- ADH and oxytocin
the ____ _____ of the medial hypothalamus supresses feeding whereas the ____ _____ promotes feedings
the ventromedial nucleus of the medial hypothalamus supresses feeding whereas the lateral hypothalamus promotes feedings
while the _____ _____ decreases body temp., the ___ ____ increases body temp.
while the anterior hypothalamus decreases body temp., the posterior hypothalamus increases body temp.
describe ventromedial hypothalamus syndrome (Frohlich syndrome)
- Frohlich syndrome is a disorder of caloric balance characterized by obesity
- the obesity reflects damage to the ventromedial nucleus of the hypothalamus
hypothermia can be caused by lesions of the ____ ____ which leaves the ____ ____ unopposed
hypothermia can be caused by lesions of the posterior hypthalamus which leaves the anterior hypothalamus unopposed
hyperthermia can be caused by lesions of the ____ ____ which can leave the ____ ____ hypothalamus unopposed
hyperthermia can be caused by lesions of the anterior hypothalamus which can leave the posterior hypothalamus hypothalamus unopposed, increasing metabolism and shivering and peripheral vasoconstriction (reducing heat loss)
