Hypothalamus Flashcards
Lateral zone nuclei (2)
Tuberomammillary nucleus
Lateral mammillary nucleus
Medial zone nuclei of hypothalamus (6)
Posterior Dorsomedial Paraventricular Preoptic Ventromedial Arcuate Suprachiasmatic
Preoptic nucleus
Integrates sensory info needed to judge deviation from set points
Thermoregulation, salt water intake, sleep
Paraventricular nucleus
Directly interfacing w/ endocrine and autonomic systems
Has glucose-sensitive neurons
Supraoptic nuclei
Release vasopressin –> maintain salt and water balance
Has osmosensitive neurons
Generate circadian rhythms for hormone release –> body temp, sexual behavior, cycles of activity
Suprachiasmatic nucleus
Sexually dimorphic nuclei
Location:
Contains:
Anterior hypothalamus, posterior to preoptic nucleus
Thermosensitive neurons
Involved in sexual orientation
Key player in feeding behavior
Appetite and consumption
Arcuate nucleus
Regulates satiety
Ventromedial nucleus
Regulates complex integrative control of growth, feeding, maturation, reproduction
Dorsomedial nucleus
All histaminergic axons in CNS originate from ____
Tuberomamillary nucleus of posterior hypothalamus
Histamine has important role in ____
maintenance of wakefulness, sleep, circadian rhythms
5 major bundles of white matter in hypothalamus
Fornix Mammillothalamic tract Mammillotegmental tract Medial forebrain bundle Hypothalamo-hypophyseal tract
Fornix connects ____ to ____
Mammillary bodies
Hippocampal formation
Mammillothalamic tract connects ____ with ___
Mammillary bodies
Anterior thalamus
Mammillotegmental traact connects ____ with ____
Mammillary bodies
Dorsal midbrain
Degeneration of fornix and mamillary bodies seen in:
Chronic alcoholism
Amnesia and confusion (Korsakoff’s syndrome)
Medial forebrain bundle runs through _____
Connects ____ to ____ (4)
Lateral hypothalamus
Hypothalamus to brainstem (below), basal forebrain, amygdala, cortex (above)
Monoaminergic superhighway connecting brainstem to cortex and uses monoaminergic neurotransmitters
Medial forebrain bundle
Hypothalamo-hypophyseal tract runs from ____ to ____ via ____
Paraventricular nucleus and supraoptic nuclei
Posterior pituitary
Pituitary stalk
Tuberoinfundibular tract runs from ___ to ___
Dopamine released here regulates ___
Arcuate nucleus
Median eminence
Secretion of prolactin from anterior pituitary gland
Bitemporal hemianopsia
Tunnel vision
1st reported clinical sign of hypothalamic and pituitary tumor
Crossed optic nerve fibers in optic chiasm serve the ____
external (temporal) visual fields
Main site where hormones, peptides and other signaling molecules cross blood brain barrier to reach hypothalamus
Median eminence
Sensitive to CSF angiotensin II
Subfornical organ (SFO)
Sensitive to serum osmolality
Vascular organ of the lamina terminalis (VOLT)
Main hypothalamic nuclei that are connected directly with autonomic areas (4)
Paraventricular
Arcuate
Ventromedial
Lateral hypothalamus
Major outputs of hypothalamus (3)
Anterior pituitary
Posterior pituitary
Pre-ganglionic autonomic efferent neurons
Releasing hormones are produced by _____ located in ____ (2)
Paravocellular/small neurosecretory cells
Paraventricular nucleus and scattered groups in medial and ventral hypothalamus
Magnocellular neurons are located in the ____ nuclei (2)
Synthesize:
Paraventricular and supraoptic nuclei
Vasopressin –> water balance
Oxytocin –> milk release/uterine contraction
Damage to pituitary stalk will sever _____
Result in ____
Hypothalmo-hypophyseal tract
Loss of vasopressin –> production of large volumes of weak urine by kidneys
Hypothalamic output to parasympathetic pre-ganglionics in _____
Midbrain: Edinger-Westphal n.
Pons/medulla: salivatory nuclei, nucleus ambiguus, dorsal vagal nucleus and sacral cord (S2-4)
Hypothalamic output to sympathetic pre-ganglionic neurons in ___
Spinal cord T1-L2 Adrenal medulla (T5-T11) --> control Epi and Norepi release
Tract composed of diffuse brainstem pathway located in PAG and descending hypothalamic axons and ascending visceral sensory axons
Dorsal longitudinal fasciculus
Hypothalamospinal pathway passes through ___
Influence ____
Midbrain and pontine tegmentum
Lateral medulla in central tegmental tract
Blood pressure, sweating, vasoconstriction, release of epinephrine and norepinephrine
Thermogenesis:
Lesion of anterior hypothalamus leads to ____
hyperthermia b/c loss of inhibitory control over thermogenesis
Thermogenesis:
Lesion of posterior hypothalamus lead to ____
Hypothermia
Body temperature matching ambient temperature
Febrile response mediated by _____
Neurons in medial preoptic area (MPOA) that are sensitive to circulating pyrogens
Sleep:
Lesions of the anterior hypothalamus produce ____
insomnia
Sleep:
Lesions to the posterior hypothalamus leads to ____
Profound state of sleepiness
Central norepinephrine (increase/decrease) feeding
Increase
Seratonin (increase/decrease) feeding
Decrease
Lesions to ventromedial nucleus result in ____
uncontrollable eating
Feeding:
Lesions to lateral hypothalamus result in ____
completely abolishing eating (aphagia) and drinking (adipsia)
Feeding:
Lesions of medial hypothalamus (ventral part) result in ____
uncontrollable eating and drinking
Salt/water intake:
Lesion to anterior hypothalamus will result ____
total loss of desire to drink
Major source of descending control of blood pressure regulation
Rostral ventrolateral medulla (RVLM) —> directly modulate baroreflx
Hypothalamo-pituitary-gonadal axis
Control onset of reproductive milestones and reproductive cycles
____ is important for onset of puberty
Body mass (leptin)
