1. Endo 2 - Linking nerves and hormones
An introduction to neuroendocrinology
Historical perspectives
Neurosecretory cells
Embryology of the pituitary gland
Anatomy and blood supply of the hypothalamic-pituitary axis
Hormones of the posterior pituitary gland
Hormones of the anterior pituitary gland
Control of hormone secretions

2. NEUROENDOCRINE INTEGRATION
NERVES HORMONES
EFFECTOR ORGANS

3. The hypothalamic-pituitary axis

4. Historical Persepctives
130 A.D. Galen: pituitary gland ‘phlegmatic glandule’ secreting waste products (pituita) into the nose
1838 Rathke (viz Rathke’s pouch): development of the pituitary gland
1886 Pierre Marie: acromegaly associated with enlarged pituitary gland
1909 Harvey William Cushing: described the symptoms associated with hypo- and hyper- pituitarism

5. Phlegmatic glandule

6. Development of pituitary gland - Rathke (1838)
Rathke’s pouch

7. Pierre Marie (1886) enlarged pituitary gland associated with acromegaly

8. Brain-pituitary connections
1930’s Bargmann and the Scharrers: histological studies identified neurosecretory cells in brain projecting to the posterior pituitary
1930 Popa & Fielding: identified hypophyseal portal veins capillaries. Dispute as to direction of blood flow
1950’s Geoffrey Harris: established neurohumoral control of anterior pituitary gland
1969 Guilleman & Schally: identified structure of TRH
1970’s The decade of neuropeptides
1980’s Gene sequencing.

9. Brain-pituitary connections
1930’s Bargmann and the Scharrers: histological studies identified neurosecretory cells in brain projecting to the posterior pituitary
1930 Popa & Fielding: identified hypophyseal portal veins capillaries. Dispute as to direction of blood flow
1950’s Geoffrey Harris: established neurohumoral control of anterior pituitary gland
1969 Guilleman & Schally: identified structure of TRH
1970’s The decade of neuropeptides
1980’s Gene sequencing.

10. DEFINING HORMONES ENDOCRINE NEUROENDOCRINE PARACRINE AUTOCRINE
INTRACRINE
Active hormone
INTRACRINE
Circulating hormone

11. Transduction of nervous signal into an endocrine signal
Neurosecretory cell
Transduction of nervous signal into an endocrine signal

12. Classical neurosecretory neurones
Chromaffin cells of the adrenal medulla
Magnocellular neurones (SON & PVN) projecting to the posterior pituitary gland
Parvicellular neurones projecting to the hypophyseal portal capillaries

13. Neurosecretory cells (A) and sympathetic innervation of endocrine glands (B)
Magnocellular
Parvicellular C
ANTERIOR PITUITARY

14. Neurosecretory cells of the hypothalamus
Parvicellular neurones
Magnocellular neurones
Neurosecretory cells of the hypothalamus

15. Embryology of the pituitary gland

16. Gross anatomy of the pituitary gland

17. Hypothalamic nuclei

18. Aminergic and serotonergic pathways of the brain

19. Blood supply of the neurohypophysis and adenohypophysis

20. Blood supply of the median eminence and pituitary gland
Internal carotid artery
Superior hypophyseal artery
Portal veins
Hypophyseal veins
Hypophyseal veins
Inferior hypophyseal artery

21. Venous drainage of the pituitary gland

22. Neurones in the hypothalamus synthesise and release hormones from the posterior pituitary
Other neurosecretory cells in the hypothalamus release their hormones into the portal capillaries in which they are transported directly to endocrine cells of the anterior pituitary gland
LH, FSH, ACTH, TSH, PRL, GH
Oxytocin, vasopressin

24. Structure of oxytocin and vasopressin (ADH

25. Control of posterior pituitary hormones
Oxytocin
Cervix/uterus
uterine contractions
Nipples
milk ejection
(neuroendocrine reflex)
Vasopressin (ADH)
Osmoreceptors/
volume receptors
permeability of collecting ducts
(V2 receptors)
Vasoconstriction
(V1 receptors)

26. Control of vasopressin release and its actions

30. Control of anterior pituitary secretions
Adrenocorticotrophic hormone – ACTH CRH
Thyroid stimulating hormone – TSH TRH
GHIH
(somatostatin)
Luteinizing hormone and follicle stimulating hormone
- LH & FSH GnRH
Prolactin – PRL dopamine (dominant control)
TRH/others
Growth hormone – GH GHRH
GHIH (somatostatin)

31. Feedback control of the H-P axis
External stimuli
HYPOTHALAMUS
Feed back
PITUITARY GLAND
EFFECTOR ORGAN

32. Factors controlling the release of growth hormone and prolactin and feedback control

33. Factors controlling the secretion of TSH and feedback control

34. Factors controlling the secretion of ACTH and feedback control

35. Hypopituitary patient resulting from a tumour
Note loss of secondary sexual characteristics