BIOM PART TWO - Lecture 2 Flashcards
How is the pituitary connected to the hypothalamus?
Through the infundibulum (stalk)
What is the whole pituitary gland protected by?
Bone
What is the Anterior Pituitary/Adenohypophysis?
An endocrine gland
What is the Posterior/Neurophysis?
Extension of neural tissue
What does Dopamine (PIH) inhibit?
Secretion of prolactin
What does Prolactin releasing hormone do?
Stimulate the release of prolactin
What does Thyrotropin releasing hormone do?
Regulates secretion of thyroid stimulating hormone (TSH)
What does Corticotropin Releasing Hormone do?
Regulates secretion of adrenocorticotropin hormone (ACTH)
What does Somatostatin do?
Inhibit secretion of Growth Hormone (GH)
What does Growth Hormone Releasing Hormone do?
Stimulate secretion of GH
What does Gonadotropin-Releasing Hormone do?
Regulates secretion of gonadotropin-releasing hormones, luteinizing hormone (LH), and follicle stimulating hormone (FSH)
In the Hypothalamic - Pituitary Adrenal Cortex, what does the Hypothalamus secrete?
Corticotropin Releasing Hormone
What does CRH stimulate?
The pituitary gland to stimulate ACTH release
What does ACTH stimulate?
The Adrenal Gland to release Glucocorticoid
What is Cortisol?
A glucocorticoid - chronic stress hormone
Where does CRH synthesis and release come from?
The hypothalamic PVN
What is Central Stimulatory Control?
- Noradrenergic
- Stimulates pre-proCRH gene and protein expression (196AA)
- Processed top CRH (41 AA)
- Stimulates pulsatile release of CRH
What are the inhibitory influences?
Physiological levels of cortisol inhibit release of CRH (and possibly inhibit pre-prOCRH gene expression)
What type of cells is CRH produced from?
Parvocellular neuroendocrine cells within the PVN
Where is CRH released at?
The median eminence (base of the brain) from neurosecretory nerve terminals, into blood vessels in the hypothalamic pituitary portal system
What do blood vessels carry?
The CRH peptides to anterior lobe of the pituitary, where they stimulate corticotropes to secrete ACTH
What do the POMC peptide family release?
ACTH and MSH
What does ACTH regulate?
Adrenal Cortex function
What is MSH?
Melanocyte Stimulating Hormone (skin pigmentation in response to UV radiation)