The Hypothalamus
Medical Neuroscience
Dr. Wiegand
Neural
NeuralInfluences
Influences
HormonalInfluences
Influences
Hormonal
The Hypothalamus
Autonomic
Autonomic
Nervous
Nervous
System
System
Limbic
Limbic
System
System
Endocrine
Endocrine
System
System
Functions of the
Hypothalamus
Autonomic nervous system regulation
Hormone production
| Endocrine regulation
| Circadian rhythm regulation
| Limbic system interaction
| Various
|
|
z
z
Temperature regulation
Feeding
1
The Diencephalon
The Diencephalon
thalamus
thalamus
fo
ix
rn
Epithalamus
Epithalamus
(Pineal
(Pineal&
&
Habenula)
Habenula)
hypothalamus
hypothalamus
Optic
Opticchiasm
chiasm
pituitary
pituitary
Mammillary
subthalamus
subthalamus
body
Pituitary
2
Divisions of the
Hypothalamus
3rd ventricle
Divisions of the
Hypothalamus
periventricular
medial
lateral
3
Divisions of the
Hypothalamus
Divisions of the
Hypothalamus
4
Tuberoinfundibular tract
HypothalamicHypophysial
Portal System
Hypothalamohypophysial tract
Functions of the
Hypothalamus
|
|
|
|
|
|
Autonomic nervous
system regulation
Hormone production
Endocrine regulation
Circadian rhythm
regulation
Limbic system
interaction
Various
z
z
|
|
Temperature
regulation
Feeding
Anterior area
influences PSNS
through projections
to brainstem PSNS
nuclei
Posterior area
influences SNS
through projections
to the lateral gray
horn
Functions of the
Hypothalamus
|
|
|
|
|
|
Autonomic nervous
system regulation
Hormone production
Endocrine regulation
Circadian rhythm
regulation
Limbic system
interaction
Various
z
z
Temperature
regulation
Feeding
|
|
|
|
Magnocellular regions of
the supraoptic and
paraventricular nuclei
produce oxytocin and
vassopressin (ADH)
Transported via axonal
transport systems
(hypothalamohypophysial
tract) to neurohypophysis
Released in circulation
Damage to supraoptic n.
⇒ diabetes insipidus
5
Functions of the
Hypothalamus
|
|
|
|
|
|
Autonomic nervous
system regulation
Hormone production
Endocrine regulation
Circadian rhythm
regulation
Limbic system
interaction
Various
z
z
|
Temperature
regulation
Feeding
Stimulating or inhibiting
hormones are
transported via the
tuberoinfundibular tract
and released in to the
pituitary portal system
and ultimately to the
adenohypophysis
Functions of the
Hypothalamus
|
|
|
|
|
|
Autonomic nervous
system regulation
Hormone production
Endocrine regulation
Circadian rhythm
regulation
Limbic system
interaction
Various
z
z
|
Input from retina to
suprachiasmatic
nucleus is then
sent through poorly
defined projections
to the pineal gland
Temperature
regulation
Feeding
Functions of the
Hypothalamus
|
|
|
|
|
|
Autonomic nervous
system regulation
Hormone production
Endocrine regulation
Circadian rhythm
regulation
Limbic system
interaction
Various
z
z
Temperature
regulation
Feeding
|
Temperature
z
z
z
z
|
Posterior n. conserves
heat
Anterior n. dissipates heat
Fever starts – sweating
Fever ends – chills
Feeding
z
z
Lateral n. induces eating
Ventromedial n. inhibits
eating
6
Limbic System (Visceral
Brain)
Mediates complex behaviors
z
Preservation of species
• securing food, defense mechanisms,
sexual behavior
Emotions
Affective behavior
z Memory
z Motivation
z
z
Components
|
|
|
|
|
|
|
|
Cingulate gyrus
Parahippocampal
gyrus
Mammillary body
Hippocampus
Anterior thalamic
nucleus
Amygdala
Septal nuclei
Dorsomedial
thalamic nucleus
7
Circuit of Papez
CingulateGyrus
Gyrus
Cingulate
Thalamocingulate
radiations
fornix
cingulum
Ant. Thalamic
Thalamic
Ant.
Nucleus
Nucleus
Mammillary
Mammillary
Body
Body
Hippocampus
Hippocampus
Mammillothalamic tract
Fornix
Amygdala
|
|
Located deep to uncus,
near tail of caudate, and
above most rostral part of
lateral ventricle inferior
horn
Wide variety of functions,
connections
z
|
lip smacking, chewing,
autonomic responses,
fear, rage, anxiety
Klüver-Bucy Syndrome
Placidity
Visual agnosia
Oral tendencies
Hypersexuality
8
9