2. Hypothalamus

3. Centre for the integration of visceral reflexes, thus maintaining constant internal environment

5. Control centres in the hypothalamus 1- Anterior centres Supraoptic (water regulation, wakefulness) Paraventricular Medial & posterior nucleus Anterior hypothalamic area (modify parasympathetic function)

7. Control centres in the hypothalamus 2- Medial centres Dorsomedial (sympath. Function) & ventromedial (satiety) nuclei

9. Control centres in the hypothalamus 3- Lateral centres Lateral hypothalamus (sympath. Function, feeding)

10. Control centres in the hypothalamus 4- Posterior centres Posterior hypothalamus Prefornical nucleus mammilary body arcuat & periventricular zone

11. Connection of the hypothalamus Afferent from:  Preolfactory area  Limbic lobe  Amygdala  Hippocampus  Non specific thalamic nuclei  GP

12. Connection of the hypothalamus Collaterals from:  Sensory ascending tracts

13. Connection of the hypothalamus Efferent to:  Neurohypophysis  Ant. Thalamic nuclei  Brain stem RF

14. Function of the hypothalamus 1- Autonomic function All autonomic functions are modified by the hypothalamus Anterior hypoth. »»»» parasympathetic Post. Hypoth., Dorsomed., Lateral »»»» sympathetic

15. Function of the hypothalamus 2- Temperature regulation Post. Hypoth. »»» reflex response activated by cold (cautanouse vasoconstriction, shivering) Ant. Hypoth. »»» heat-loosing mechanisms (cutanouse vasodilatation, sweating)

16. Function of the hypothalamus 3- Body water regulation Thirst centre in the supraoptic (secret vasopressin) region of the hypoth.

17. Function of the hypothalamus 4- food intake regulation Feeding centre (Lateral hypoth) Stimulation:  Hunger, desire to search for food »»» Obesity Damage: Sever loss of appetite (anorexia) Satiety centre (ventromedial nucleus) Stimulation: Anorexia Damage :  Feeding centre become active »»» hyperphagia & obesity (hypothalamic obesity)

18. Function of the hypothalamus 5- Defence reaction Expression of rage, fear and other emotion

19. 6- Wakefulness & sleep hypothalamus is part of RAS involved in initiation & maintenance of alert & wakefulness Stimulation of anterior hypoth. »»»» sleep Lesion of anterior hypoth. »»»» wakefulness »»»» death from exhaustion Supraoptic nucleus ( dawn to afternoon, dusk)

20. Function of the hypothalamus 7- Relation to cyclic phenomena Hypoth. Lesion »»»» disruption of circadian rhythm( secretion of ACTH & melatonin)

21. Function of the hypothalamus 8- behavioural & sexual function Hypoth. Is part of the limbic system Stimulation of certain parts of the hypoth. »»»» fear, pleasure, feeding, emotional reaction, sexual stimulation

22. Function of the hypothalamus 9- Neuroendocrin function Control of ant. & post pituitary