HYPOTHALAMUS

List the main functions of the hypothalamus

regulation / homeostasis

limbic systemm - emotions

hormonal control - fight/flight, sleep/wake, arousal,

What homestatic mechanisms are regulated by the hypothalamus

thirst, blood volume, temperature

Where in the brain is the hypothalamus located?

Diencephalon

dorsal to pituitary

What key brain structure, other than the thalamus helps to elavate sympathetic activity?

rostral ventrollateral medulla (brainstem)

Key nuclei and specific behavioural functions :

Label these nuclei of the thalamus.

Which nuclei of the hypothalamus are in the medial / caudal?

What is the fucntion of the medial / caudal nuclei of the thalamus??

Which nuclei are in the rostral / chiasmatic ?

What is the function of the rostral / chaiasmatic nuclei of thalamus?

Where in the brain does the circadian rhythm control come from?

suprachiasmatic nucleus

Describe in detail the pathway that controls circadian rhythm.

Eye detects light → signal goes to SCN → Paraventricular nucleus sends signals to spinal cords → neurones to pineal gland, releases melatonin.

Where do signals from SCN go?

to hypothalamus

What condition can a leison in the SCN cause?

narcolepsy

What two hypothalamic feeding regions regulate appettite?

Paraventricular nucelus :

appetite peripheral stimultion - leptin from fat supresses appetite, ghrelin stimulates appetitie

energy imblances - hiberntion, migration, reproduction, lactation

Explain a theory for long term control of hunger

Lipostst theory

• leptin sensing neurones in hypothalamus

• leptin induces expression of POMC

  • precursor protein that generates MSH

• MSH acts on MC4 receptors

Explain a theory of short term control of appetite

glucostat theory

• hunger waxes and wanes as a function of glucoose levels

• hypothalamic glucose sensing neurones