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mechanism of neurosecretory cells
- peptide hormones are packages into the secretory granules within golgi apparatus
- once packaged, it's carried along the axoplasmic transport
- along the transport, the larger proteins or hormones are broken into smaller hormones (final product) and stored in the hering bodies
- the hormones are released by action potentials
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GnRH
- decapeptide
- exogenous (outside) GnRH, when given to patients it causes spematogenesis in males and ovulation in females
- infetility is treated by exogenous GnRH
- also regulated GnRH receptors in brain by ultra-short loop (was used for male contraception)
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Circulation of Hypothalamus
- blood supply is by hypothalamo hypophysial portal system
- hypothalamus is highly vascularized - trauma causes bleeding and death
- hypothalamus is supplied by circle of willis (internal carotic artery and posterior artery and medial hypophysial artery)
- veins of galen are responsible for blood draining
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circulation of anterior pituitary
- blood from superior hypophysial arteries (comes from interal carotid arteries) which flows through primary capillary plexus into the medium eminence and pituitary stalk
- from primary plexus --> arises hypophysial portal system which ends in anterior pituitary to form secondary plexus, which supplies blood to the secretory cells
- blood drains by efferent veins
posterior pituitary is supplied by inferior hypophysial artery
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hypothalamus
- below the thalamus
- full of nervous tissue
- controls most of body activities, bot only hormones releasing
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portal hormones
different factors released in the hypothalamic portal system, which controls anterior pituitary hormones
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systematic hormones
posterior pituitary hormones are released into circulation
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