Hypothalamus Flashcards
Main function of Hypothalamus
Homeostasis.
It does all the stuff that you don’t want to have to think about (heart rate, temperature, etc.)
Location of hypothalamus
Under and just anterior to thalamus.
The nuclei are not morphologically distinct.
Important hypothalamic nuclei
ARCUATE NUCLEUS (release hormones for ant. pituitary– affected by stress)
SUPRACHIASMATIC NUCLEUS (biological clock)
PARAVENTRICULAR NUCLEUS (ant. and post. pituitary hormones)
MAMMILLARY NUCLEUS (memory)
Fornix
VERY STRONG input which runs from hippocampus to hypothalamus
Stria Terminalis
STRONG input which runs from the amygdala to hypothalamus. Control fear, anger, happiness etc. responses and the physical changes associated with them.
Medial forebrain Bundle
Conscious perception of visceral functions (heart rate, BP, respiration, GI system)
When you think of visceral function, think
SOLITARY NUCLEUS
Important neurotransmitters associated with hypothalamus
Dopamine (ventral tegmentum areas), Norepinephrine (LOCUS CERULEUS), Serotonin (go everywhere– midline raphe nuclei)
Hypothalamic outputs
Widespread cortical areas via anterior thalamic nucleus and back to the cingulate (limbic) cortex.
Papez circuit has a lot to do with…
Limbic function
Papez circuit
(1) Cortex (cingulate gyrus)
(2) Hippocampus
(3) Hypothalamus (mammillary)
(4) Thalamus (anterior nucleus)
(5) Cortex (cingulate gyrus)
The 2 types of hypothalamic pituitary control
It uses the pituitary to affect some organs at a distance via the blood stream.
(1) DIRECT- via posterior pituitary (neurohypophysis)
(2) INDIRECT- via anterior pituitary (adenohypophysis)
Servomechanism
How hypothalamus operates.
It changes the set points for different processes and adjust the body accordingly. Feedback detectors update it on the current status.
What sits right next to posterior cerebral arteries of the circle of willis?
Mammillary bodies (as well as pituitary and optic chiasm)
If you’re unsure of what something is traveling through in relation to the hypothalamus, what is usually a good guess?
Median (or medial) forebrain bundle
