Hypothalamic-Pituitary System Flashcards
Hypothalamic neurons are…
Neurosecretory, meaning that they synapse onto blood vessels and release hormones directly into the bloodstream
Where does the pituitary gland reside?
Below the hypothalamus
Hypophyseal portal
Blood flow that links hypothalamus and (anterior) pituitary
Posterior pituitary gland
Extension of hypothalamus
Axons (tails) of hypo neurosecretory cells ( in hypothalamus) release..
Peptide neurohormones
ex: oxytocin, ADH
Neurohormones of posterior pituitary are released…
Directly into bloodstream from nerve synapses
-Go to heart and go to periphery
Anterior pituitary
More directly connected with hypothalamus
Neurosecreted hormones from hypothalamus enter…
Hypophyseal portal system
What does the hypophyseal portal system do in the anterior pituitary?
It “bathes” AP cells in blood saturated with hypothalamic releasing hormones (-RH)
What ending to AP cells usually have?
_____trope
How do AP cells respond when the receptors they express are stimulated by RH?
Releases pituitary hormones
Releasing hormone always means…
Hormone coming from hypothalamus and going to the anterior pituitary
5 Hormones coming from hypothalamus
- GHRH
- GHIH
- TRH
- CRH
- GnRH
GHRH
Growth hormone-releasing hormone
GHIH
Growth hormone inhibiting hormone
TRH
Thyroid hormone
CRH
Corticotropin
GnRH
(Sometimes LHRH) Gonadotropin
2 Hormones coming from posterior pituitary
ADH
Oxytocin
ADH
Antidiuretic hormone, AKA vasopressin, targets kidneys
Oxytocin
Targets breasts, uterus, brain testes
6 Hormones from the anterior pituitary
GH TSH ACTH PRL FSH LH
GH
Growth hormone
Released by somatotropes
Release stimulated by GHRH, inhibited by GHIH
TSH
Thyroid-stimulating hormone
Released by thyrotropes
Release stimulated by TRH
ACTH
Adrenocorticotropic Hormone
Released by corticotropes
Release stimulated by CRH
PRL
Prolactin
Released by lacotropes
Complex regulation (No RH identified)
FSH and LH
Follicle stimulating hormone and Lutenizing Hormone
Released from gonadotropes
Release stimulated by GnRH
