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Flashcards in The Hypothalamus Deck (28):

What is the hypothalamus

It is funnel shaped, and obliquely oriented. At the end of the funnel we find the hypophysis.


What are the borders of the hypothalamus

Anteriorly : the lamina terminalis, anterior commisure
Posteriorly: the tegmentum
Inferior: infundibulim and optic chiasm and the tuber cinereum
Superiorly: sulcus terminalis, and hypothalamic sulcus


What are the visible aspects on the base of the brain of the hypothalamus

Mammilary bodies, tuber cinereum, infundibulim


The hypothalamus is surrounded by which group of blood vessels

The circle of willis


Which systems does the hypothalamus contribute to

The autonomic nervous system
The endocrine system
The limbic system


What are the divisions of the hypothalamus in the coronal plane

The periventricular region
The medial region
The lateral region. Note that the medial and lateral region are separated by a bundle of white matter consisting of the column of the fornix and the mammilothalamic tract


What are the divisions of the hypothalamus when divided in the saggital plane

The anterior suprachiasmatic region.
The middle tuberal region
The posterior mammilary region.


What are the 2 regions of the hypothalamus related to feeding

The lateral hypothalmic nucleus(hunger center), ventromedial nucleus (satiety center)


What are the autonomic functions of the anterior and posterior hypothalamus

The anterior hypothalamus has an excitatory effect of the parasympathetic system.
The posterior hypothalamus has an excitatory effect on the sympathetic system


What is the limbic system? What is its function? How does it use its mammilothalamic tract and mammilotegemental tract?

It is our mammalian brain (mating/olfaction) . It is made of the limbic lobe (which it on the border of the cortex), the dentate gyrus, the hippocampal formation, the anterior nuclei of the thalamus, and the mammilary body of the hypothalamus.
The mammilothalamic tract allows the hippocampus to project to the anterior nuclei of the thalamus.
The mammilotegemental tract allows it to receive information from the reticular formation


What is the circuit of Papez

When information goes from the entorhinal cortex to hippocampus to mammilary body to anterior nucleus of thalamus to cingulate gyrus to parahippocampal gyrus back to the entorhinal cortex.


Where is the entorhinal cortex

Close to the hippocampus, at the level of the parahippocampal gyrus. It receives information from the associative areas of the cortex


What are the neural and blood borne inputs of the hypothalamus

Ascending pathways from visceral and somatic sources
Hippocampus (fornix)
Septal Area and orbitofrontal cortex (medial forebrain bundle, MFB)
Primary olfactory cortex (MFB)
Mediodorsal nucleus of the thalamus
Tegmental Nuclei
Raphe Nuclei (MFB)
Locus Ceruleus Amigdala ( stria (MFB) terminalis , ventral amigdalofugal pathway) Retina: medial root of the optic tract
BLOOD BORNE: hormones, temperature, osmolarity


What are the NeuroEndocrine and neural outputs from the hypothalamus

NeuroEndocrine is to the pituitary gland
Neural is : Ascending and descending pathways, amygdala, mammillothamlmic tract, inferior thalamic peduncle to the mediodorsal nucleus of the thalamus, brainstem and spinal cord


Hypothalamic syndromes can cause which 3 kinds of disorders

Endocrine and metabolic disorders.
Vegetative disorders.
Mood disorders


Where is the thalamus located?

it is under the tele choroidea


where is the habenular commissure?

right under the splenium of the corpus callosum


what is the function of the habenular trigone?

the habenular nuclei in this trigone is responsible for sending information to areas of the midbrain involed in dopamine release. It also links to areas involved in serotonin release


the substantia nigra releases what hormone?



the raphe nuclei release what hormone?



what are the nuclei involved in water balance

the paraventricular nucleus, supraoptic nucleus


which nuclei is responsible for maintaining the sleep-wake cycle?

the suprachiasmatic nuclei. It has connections with the pineal gland- which influences melatonin release and reticular formation inhibition


Which nucleus influences sexuality?

the preoptic nucleus, it regulates the release of gonadotropin hormone from the adenohyophysis


which nuclei is responsible for savage behavior in animals

the dorsomedial nucleus


the arcuate / infundibular nucleus is responsible for?

producing prolactin. It influences lactation, sexual gratification, immunotolerance of the fetus, dopaminergic neurons


the paraventricular nucleus is responsible for what 2 things?

water balance and stress response. It regulates the release of corticotropin releasing hormone


what are circumventricular organs?

they are paramedian organs in areas where the blood brain barrier I weakened. Here the neurons are in contact with the blood and the CSF


where is the subthalamic nucleus?

it is under the paraventricular nucleus. above the red nucleus and the substantia nigra