Hypothalamus & Limbic System Flashcards
Diencephalon
epithalamus, thalamus, hypothalamus, and subthalamus
Hypothalamus is in charge of ________ and _______
- homeostasis and regualtion
- motivated behavior (stereotyped behavior)
Motivated behavior
four F’s: feeding, fighting, flighting, finding a mate
alertness, motor action, emotion
(stereotyped behavior)
ventral landmarks of hypothalamus
optic chiasm
tuber cinereum (infundibulum & medial eminence)
mammillary bodies
the hypothalamus forms the _____ and ______ wall of the third ventricle
floor and ventrolateral wall
Hypothalamic regions
- supraoptic
- tuberal
- mammillary
hypothalamic areas
- anterior hypothalamic area (autonomic outflow–temperature regulation–heat dissipation center)
- lateral hypothalamic area (hunger center)
- posterior hypothalamic area (temperature regulation–heat conservation center–sensitive to cold)
supraoptic nuclei
ADH secretion mostly
a little oxytocin secretion
paraventricular nuclei
primarily oxytocin secretion
little ADH secretion
ventromedial nuclei
satiety center and rage
arcuate nuclei
releasing hormone secretion for control of anterior pituitary gland
neurosecretory hormones
oxytocin
ADH
Fornix
also called cortico mammillary
arises from hippocampus and ends in mammillary bodies.
part of limbic system (motivated behaviors)
hypothalamus-hypophyseal tract
neurohormone secretion (oxytocin and ADH)
dorsal longitudinal fasciculus
major output to lower centers (autonomic PNS and Sympathetic)
medial forebrain bundle
runs from anterior to posterior connecting nuclei and areas
integrate the functions of various centers
straia terminalis
extends from amygdala (part of basal ganglia responsible for rage) to preoptic, ventromedian and anterior hypothalamic nuclei
function of hypothalamus
control and regulation of ENDOCRINE, AUTONOMIC, AND MOOD
- feeding (VMN–saiety; Lateral Hyp–hunger)
- water balance (supraoptic nuc.–ADH) Loss of ADH–> diabetis insipidus
example of hypothalamic control of autonomic NS
temperature regulation
neurogenic hypertension
hypothalamus as part of limbic system is a major contributor to _____
emotion
How does the hypothalamus control anterior pituitary secretion?
- releasing hormones secreted by hypothalamic neurons into hypothalamohypophyseal portal circulation–> affects secretion of pituitary trophic hormones
- negative feedback of blood hormones affects both hypothamic and pituitary secretion
example of negative feedback loop
excess LH stops ovulation by producing antibodies
how does the hypothalamus control posterior pituitary secretion?
- supraoptic and paraventricuar nuclei secrete neurohoromones
- their cell membranes respond to changes in blood osmolality
- increase in blood volume will inhibit ADH secretion and result in water diuresis
- absence of ADH can cause diabetes insipidus
VMN is the ____ center while _____ is the hunger center
VMN–satiety
Lateral hypothalmamic area is hunger
* lesion in VMN–fat
* lesion in lateral hypothalamus–loss of appetite
anterior hypothalamus is _____ center
while posterior is ______ center
anterior–heat disposal (too hot)
posterior–heat maintenance (too cold)
reticular activating system
multisynaptic network that receives impulses from ascending and descending tracts and projects to cortex for awakeness
lesion in reticular activating system
coma
lesion in VMN
overeating and rage
temporal lobes also involved because of presence of amygdala
neurogenic hypertension
input from hypothalamus on sympathetic NS via dorsal longitudinal fasciculus
limbic lobe
cingulate gyrus, isthmus, parahippocampal gyrus, uncus
limbic system
cingulate gyrus, isthmus, parahippocampal gyrus, uncus, hypothalamus, anterior thamaic nucleus, fornix, interconnecting tracts (mammilothalamic) and amygdala
limbic system in charge of
emotional coloring of thought, physical signs and symptoms of emotion, recent memory, stereotyped behaviors ( 4 F’s)
