REVIEW
NS102 HYPOTHALAMUS Review 11/9/06 seheekim CORPUS CALLOSUM
Fig. 5-20 HBCB
THALAMUS FORNIX
ANTERIOR COMMSSURE
2 OUTPUT FUNCTIONS Hormonal/Endocrine Output (Controls pituitary) Visceral Output (Controls ANS)
LAMINA TERMINALIS
PITUITARY
Divisions of the Hypothalamus 1. Preoptic region 2. Supraoptic region 3. Tuberal region 4. Mamillary region
Divisions of the Pituitary Gland 1. Anterior Lobe 2. Posterior Lobe
ANTERIOR
POSTERIOR
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Posterior Lobe Derived from the neural tube Neurohypophysis Anterior Lobe Derived from the gut Produces most of the endocrine substances (hormones) which the pituitary gland puts out adenohypophysis
ANTERIOR
POSTERIOR
1. PRE OPTIC REGION
Pre Optic Nucleus Sexually dimorphic nucleus Produces gonadotropin releasing hormone Gonadotropin releasing hormone stimulates the anterior pituitary to produce and secrete the real gonadotropin hormone Gonadotropin= gonad stimulating hormone
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2. SUPRAOPTIC REGION
Supraoptic nucleus Peraventricular nucleus Anterior nucleus Suprachiasmatic nucleus
Periventricular & Supra optic Nuclei
Produce oxytocin and vassopressin Hormones are transported by axons of these two nuclei into the posterior lobe of the pituitary gland Hormones are stored in those axons until released into local capillaries and carried away by the vascular system
SUPRAOPTICOHYPOPHYSEAL TRACT
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Periventricular & Supra optic Nuclei
Produce oxytocin and vassopressin Hormones are transported by axons of these two nuclei into the posterior lobe of the pituitary gland Hormones are stored in those axons until released into local capillaries and carried away by the vascular system
PLF
Anterior Hypothalamic Nucleus
Produces parasympathetic responses Reduces heart rate Enhances GI activity
SUPRAOPTICOHYPOPHYSEAL TRACT
Periventricular & Supra optic Nuclei
Produce oxytocin and vassopressin Hormones are transported by axons of these two nuclei into the posterior lobe of the pituitary gland Hormones are stored in those axons until released into local capillaries and carried away by the vascular system
Anterior Hypothalamic Nucleus
Produces parasympathetic responses Reduces heart rate Enhances GI activity
Suprachiasmatic Nucleus
Sets your light-stimulated circadian rhythm Sits above the optic chiasm Supplied by small groups of retinal Inputs from the optic chiasm (Light Flux) Nucleus fibers go all the way down spinal cord then back up to stimulate production of melatonin in the pineal gland
Optic chiasm
SUPRAOPTICOHYPOPHYSEAL TUBERAL TRACT
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3. REGION
Arcuate nucleus Dorsal Medial nucleus Ventral Medial nucleus
Arcuate Nucleus
Just above the start of the pituitary stalk Produce all of the release hormones (exception of preoptic nucleus) Axons leave the nucleus and terminate into the base of the pituitary stalk Axons terminate as a capillary plexus known as the portal system Portal system/capillary plexus takes blood now carrying these mock hormones into Anterior lobe and releases them, triggering the production of hormones by the anterior lobe
Real hormones produced here
HYPOTHALAMOHYPOPHYSEAL TRACT
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Arcuate Nucleus
Just above the start of the pituitary stalk Produce all of the release hormones (exception of preoptic nucleus) Axons leave the nucleus and terminate into the base of the pituitary stalk Axons terminate as a capillary plexus known as the portal system Portal system/capillary plexus takes blood now carrying these mock hormones into Anterior lobe and releases them, triggering the production of hormones by the anterior lobe
** remember that the preoptic nucleus Is the one other nucleus that makes Releasing hormone (gonadotropin releasing hormone
Real hormones produced here
HYPOTHALAMOHYPOPHYSEAL TRACT
Arcuate Nucleus
Just above the start of the pituitary stalk Produce all of the release hormones (exception of preoptic nucleus) Axons leave the nucleus and terminate into the base of the pituitary stalk Axons terminate as a capillary plexus known as the portal system of the anterior pituitary Portal system/capillary plexus takes blood now carrying these mock hormones into Anterior lobe and releases them, triggering the production of hormones by the anterior lobe
Dorsal & Ventral Medial & Lateral nuclei
Involved controlling/balancing in hunger and satiety and oral aggressive behavior Bilateral destruction of VM animal keeps eating Bilateral destruction of VL animal does not eat
HYPOTHALAMOHYPOPHYSEAL TRACT
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4. MAMMILLARY REGION
Posterior Hypothalamic nucleus Mammillary Body
Posterior hypothalamic nucleus
Head nucleus for sympathetic nervous system Produces sympathethic nervous responses Increased heart rate Inhibition of GI activity
PLF
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Posterior hypothalamic nucleus
Head nucleus for sympathetic nervous system Produces sympathethic nervous responses Increased heart rate Inhibition of GI activity
Mammillary Body
Integrates the information coming in from the limbic system via the fornix from the midbrain tegmentum
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