Endocrine Physiology: Posterior Pituitary Gland & Diseases of the Pituitary Gland

Week 5: Thursday, September 25th

the _______ has unmyelinated axons with secretory granules

neurohypopsis

neurohypopsis hormones are synthesised in the _______

magnocellular neurons in the hypothalamus

hypothalamic hormes travel down axons and are storied in the _______ near blood supply

posterior lobe

true or false: the neurohypopsis has a lot of nerves, but low blood vessels

true

hypothalamic neurons, _______ and _______ are activated by other brain regions (sensory signals)

paraventricular and supraoptic nuclei

action potentials occur in the infundibulum, causing calcium to enter the nerve terminals, thus causing secretory vesicles, containing _______ and _______, to release from terminals

oxytocin (OXT) and vasopressin (AVP)

true or false: neurophysin, a protein carrier, can prevent OXT and AVP release if it has a mutation, which will cause diseases

true

_______ increases uterine contractions, causes milk ejection and paracrine effects in reproductive tissue

oxytocin (OXT) 

_______ stimulates water retention (V₂ G-protein receptors), causes muscle contractions (V₁), and stimulates ACTH release

vasopressin (AVP)

true or false: OXT and AVP evolved from two different genes, and act as neurotransmitters to affect behavior

false. OXT and AVP evolved from a single ancestral gene, and act as neurotransmitters to affect behavior

true or false: the hypothalamus releases neurohormomes (hypopysiotropic) into the hypothalamo-hypophseal portal system

true

_______ is a hypophysiotropic that has 3 amino acids, stimulates TSH release, is made in the paraventricular nucleus, and acts as a peptide neurotransmitter else where in the brain (behavior)

thyroid releasing hormome (TRH)

_______ is a hypophysiotropic that has 10 amino acids, stimulates FSH and LH release, is made in the arcuate nucleus, is released in pulses, and acts as a neurotransmitter elsewhere in the brain (behavior)

gonadotropin releasing hormome (GnRH) 

_______ is a hypophysiotropic that has 44 amino acids, stimulates GH release, is made in the arcuate and ventralmedial nuclei, and found in the GI tract and pancreas

growth hormone-releasing hormone (GHRH)

_______ is a hypophysiotropic that has 20 amino acids, stimulates GHRH and GH release, and is made in the hypothalamus and stomach (regulate feeding behavior)

ghrelin

_______ is a hypophysiotropic that has 41 amino acids, stimulates ACTH release from the adenohypopsis, and is made in the pair of ventricular nuclei

corticotropin releasing hormone (CRH)

true or false: placental CRH is involved in reproduction, and other paraventricular cells make AVP, which also stimulates ACTH release

true

true or false: Dopamine is a hypophysiotropic that has 1 amino acid, and stimulates prolactin release

false. Dopamine is a hypophysiotropic that has 1 amino acid, and inhibits prolactin release 

_______ is a hypophysiotropic that has 14-28 amino acids, inhibits GH, is made in paraventricular and preoptic areas, and found in the GI tract, pancreas, and brain

somatostatin

the hypothalamus secrets _______ hormones

releasing

true or false: one neurohormone can regulate only one adenohypopsis hormone

false. one neurohormone can regulate more than one adenohypopsis hormone (THR, somatostatin)

neurohormoes act on pituitary cells by binding to their _______

G-proteins

true or false: hypothalamic hormone-producing neurons are influenced by other brain regions and plasma hormones, but don’t affect neural activity themselves

false. hypothalamic hormone-producing neurons are influenced by other brain regions and plasma hormones, and affect neural activity themselves

one level of hypothalamic hormone feedback is _______ from the pituitary, whose hormones can feedback

direct feedback

one level of hypothalamic hormone feedback is _______ from the hypothalamus; pituitary/target gland hormones can feedback

indirect feedback

one level of hypothalamic hormone feedback is _______ from the pituitary-hypothalamus; pituitary hormomes feedback to hypothalamus directly

auto/short feedback

hypothalamic hormomes can be influenced by _______, such as semsory input from light/dark cycles, stress, and temperature

the external environment

hypothalamic hormomes can be influenced by _______, in which target gland hormomes can adjust hypothalamic/pituitary secretion (classic endocrine feedback)

the internal environment