The Endocrine System: Hypothalamus and Pituitary Gland Flashcards
Hypothalamus and Pituitary
What is the generalized function of the hypothalamus and pituitary?
Relay stations that act in sequence
Hypothalamus
What is the anatomy of the Hypothalamus?
Essentially just two nuclei with processes that extend down into the posterior pituitary
Histology = brain/nervous tissue
Hypothalamus
What is the function of the Hypothalamus?
Releases peptide hormones that stimulate the pituitary
Hypothalamus
What triggers release of hormones from the Hypothalamus?
Sensory stimuli: Light, olfactory, autonomic, etc.
Other stimuli: Blood-bourne sterioids, hormones, blood glucose, blood pressure, stress, etc.
Hypothalamus
What happens to hormones released by the Hypothalamus?
- They accumulate in the axons fo the neurohypophysis
- Release in the median eminence that diffuse into the adenohypophysis
Hypothalamus
What hormones, from the Hypothalamus, accumulate in the axons in the neurohypophysis?
- Oxytocin
- Vasopressin
Hypothalamus
What hormones, from the Hypothalamus, diffuse into the adenohypophysis?
- Somatostatin
- Dopamine
- GHRH
- CRH
- GnRH
- TRH
Hypothalamus
Somatostatin
Inhibits GH and insulin secretion
Hypothalamus
Dopamine
Inhibits prolactin secretion by the pituitary
Directly impacts pituitary
Hypothalamus
Growth Hormone Releasing Hormone (GHRH)
Stimulates GH secretion by pituitary
Hypothalamus
Corticotropin-Releasing Hormone (CRH)
Stimulates ACTH secretion by the pituitary
Hypothalamus
Gonadotropin-Releasing Hormone (GnRH)
Stimulates LH/FSH secretion by the pituitary
Hypothalamus
Thyrotropin-Releasing Hormone (TRH)
Stimulates TSH secretion by the pituitary
The Pituitary Gland
What is the function of The Pituitary Gland?
- Receives signals from the CNS (specifically the hypothalamus)
- Sends signals to other endocrine glands and organs
The Pituitary Gland
What are the two parts of The Pituitary Gland?
- Neurohypophysis - posterior pituitary (nerve tissue) - Pars nervosa
- Adenohypophysis - anterior pituitary (glandular tissue - Pars distalis