Functional Anatomy and Physio of the Hypothalamus and Pituitary Flashcards
6 Anterior pituitary hormones
ACTH TSH LH FSH GH Prolactin
2 posterior pituitary hormones
Vasopressin
Oxytocin
How does storage and release differ between anterior and posterior pituitary?
The anterior produces its own hormones and secretes them
The posterior pituitary stores and releases hormones produced from the hypothalamus
Long feedback loop
Target hormone feeds back on the PITUITARY, HYPOTHALAMUS, and/or the CNS to regulate the axis
Short feedback loop
Anterior pituitary hormone feeds back on the HYPOTHALAMUS to regulate the axis
Very short feedback loop
Anterior pituitary hormone feeds back on the PITUITARY to regulate the axis
Median Eminence
Located at the base of the hypothalamus
Highly vascularized neural tissue
Interface between neural and peripheral endocrine systems
Has a leaky blood brain barrier here so its where the hormones are released
How do hormones get from the hypothalamus to the anterior pituitary?
Hypothalmic hypophyseal portal system
Where does the anterior pituitary get blood from?
Received portal venous inflow from the median eminence
Where does the posterior pituitary get blood from?
Receives arterial blood from the inferior hypophyseal artery
Path of hormones from hypothalamus to anterior pituitary
Releasing hormones are secreted into the primary plexus (median eminence) from hypothalamic neurons
Travel down portal vessels in the pituitary stalk to anterior pituitary
Act on the endocrine cells of the anterior pituitary (secondary plexus)
What type of capillaries are present in the primary and secondary plexuses
Fenestrated
Hypothalamic releasing hormones are peptide hormones (large molecules)
6 hypothalamic releasing hormones
GHRH TRH CRH GnRH Somatostatin Dopamine
2 common functions for the hypothalamic releasing hormones
Promote production and release of peptide hormones of the anterior pituitary
Each of them can regulate the secretion of specific set of hormones
What type of receptors do hypothalamic releasing hormones bind to?
Extracellular receptors (GPCRs)
