Fundamentals Of Hormones Flashcards
How does insulin affect glucose metabolism in the brain
It does not
Adenohypophysis Vs neurohypophysis
AP Vs PP
What are the two main nuclei in the Hypothalamus that secrete Oxytocin and Vasopressin
Supraoptic nuclei and paraventricular nucleus
What ventricle lies just above the hypothal
Third ventricle
What nucleus releases GHRH
Arcuate nucleus
What nucleus release GnRH
Preoptic nucleus
What nucleus releases CRH
Paraventricular nucleus
What nucleus releases somatostatin
Periventricular nucleus
Where are the vesicles containing oxytocin/ Vasopressin stored in
PP axon ending
What does somatostatin inhibit
GH and TSH
What cells produce GHRH
Somatotrophs
What inhibits prolactin secretion from what cell
Dopamine acts on lactotrophs
Which hormones are made in advance and which are synthesized on demand
Only steroid hormones are synthesised on demand
Do steroid and thyroid hormones have short or long half life’s
Steroid and thyroid hormones have long half lives
Which hormones are bound to carrier proteins
Steroid and thyroid
Do steroid hormones bind to cytoplasmic or membrane receptord
Can be both
Which hormones have non genomic actions
Peptide, Catecholamines and some steroid hormones
Which hormones have genomic mechanisms
Some peptide hormones, steroid and thyroid hormones
What is the role of GLP
Stimulates production of insulin from pancreas due to glucose in lumen being senses by endocrine cells in small intestines
Which organs do PTH work on
Gut, bone and kidney
What causes production of calcitrol and what does calcitrol do
PTH, calcitrol increases intestinal absorption of Ca2+
What three chemicals raise blood glucose
Glucagon
Epinephrine
Cortisol
What is permissive for sexual maturation
Thyroid hormone
What hormone is responsible for epinephrine efficacy
Thyroid hormone
How does growth hormone affect efficacy of insulin (mech)
Decrease number of receptors
Treatment for carcinomas
More likely to be surgery for lumps
Chemo or radiotherapy for small foci
Cause of pseudohypoparathyroidism
Inheritance of defect in G protein so there is no linking of receptor to Adenyl cyclase
Should IGF 1 or GH be tested in children
GH!!
What does Dexamethasone suppression test do at low dose and high dose
Low dose suppresses pit ACTH and cortisol in normal individuals but not pit adenoma
High dose suppresses ACTH in pit adenoma but not cortisol producing adrenal adenoma or ectopic ACTH producing tumour
Role of SynACTHen stimulation test
Quantifies adrenal function or insufficiency
Low dose to measure cortisol production
High dose to measure total adren cortex function
What nucleus releases dopamine
arcuate nucleus
What nucleus releases TRH
paraventricular nucleus
Where is the prohormone formed and what does it pass through? What happens to it after that
Formed after enzymes in ER chop off signal sequence, and it goes through Golgi Apparatus and buds off Golgi in secretory vesicles with enzymes, before becoming active hormone
Impt peptide hormones to know ( apart from main neurohormones)
hCG, Leptin, Ghrelin, Insulin
What enzyme involved in insulin signalling
Tyrosine Kinaseq
what other hormone can TRH stimulate production of
Prolactin
Where are the receptors for thyroid hormones located
In the nucleus
