Hypothalamus

Hypothalamus

Hypothalamus

- extends from the region of the optic chiasma to the caudal border of the mammillary bodies

- lies bellow the thalamus and forms the floor and the inferior part of the lateral walls of the third ventricle

Optic Chiasma

point of decussation of the optic nerve itself.

Posterior Hypothalamus

part of the hypothalamus for cold dissipation.

Anterior Hypothalamus

part of the hypothalamus for heat dissipation.

• Mammillary Region

• Tuberal Region

• Supraoptic Region

• Preoptic Region

hypothalamic nuclei.

Mammillary Region

- adjacent to the midbrain

- most posterior part of the hypothalamus

- includes:

• Mammillary bodies

• Posterior hypothalamic nuclei

Mammillary Bodies

responsible for short term memory and emotion.

Posterior Hypothalamic Nuclei

responsible for the regulation of temperature specifically in response to cold.

Tuberal Region

- the widest part of the hypothalamus

- includes

• Dorsomedial nucleus

• Ventromedial nucleus

• Arcuate

Dorsomedial Nucleus

responsible for emotion, specifically rage.

Ventromedial Nucleus

responsible for appetite, specifically for body weight and insulin regulation.

Arcuate

- infundibulum which connects the pituitary gland to the hypothalamus

- also responsible for feeding

Supraoptic Region

- lies superior to the optic chiasma

- includes

• Paraventricular nucleus

• Supraoptic nucleus

• Anterior hypothalamic nucleus

• Suprachiasmatic nucleus

Paraventricular Nucleus

responsible in synthesizing oxytocin.

Supraoptic Nucleus

produces antidiuretic hormone/vasopressin.

Anterior Hypothalamic Nucleus

responsible for temperature regulation specifically heat.

Suprachiasmatic Nucleus

for control of circadian rhythm.

Preoptic Region

- anterior to the supraoptic region

- includes:

• Medial preoptic nuclei

• Lateral preoptic nuclei

Medial and Lateral Preoptic Nuclei

both control the parasympathetic system as a whole.

• Control of the ANS

• Production of hormones

• Regulation of emotional and behavioral pattern

• Regulation of eating and drinking

• Control of temperature

• Regulation of circadian rhythms and states of consciousness

functions of the hypothalamus.

• Regulation of heart rate

• Movement of food through the GIT

• Contraction of urinary bladder

majoral visceral activities controlled by the hypothalamus.

Anterior Pituitary Gland

gland regulated by the hypothalamus in secreting/inhibiting hormones.

Lateral Portion

the hunger center of the hypothalamus.

Medial Portion

part of the hypothalamus that is responsible for eating and satiety.

Suprachiasmatic Nucleus

serves as the body’s internal body clock.

Epithalamus

- a small region superior and posterior to the thalamus

- consists of:

• Pineal gland

• Habenular nuclei

Pineal Gland

- secretes melatonin

- about the size of a small pea and protrudes from the posterior midline of the third ventricle

Habenular Nuclei

involved in olfaction, especially emotional responses to odors.