HES 111 midterm I Flashcards
What is the endocrine system?
A series of organs throughout the body that secrete horomones in response to stimulus
Name some bodily functions the endocrine sytsem is involved in?
metabolism, reg of gene expression, growth, reproduction
What are the two categories of endocrine organs and what are some examples in each
Endocrine: ant pit, thyroid, parathyroid, thymus, adrenal corte, pancreas, ovaries/testes
Neuroendocrine: hypothalamus, pineal gland, post pit, adrenal medulla
What are the 4 neuroendocrine organs?
Hypothalamus, adrenal medulla, post pit and pineal gland
what must a horomone bind to to exert action?
Its receptor
What is the difference between a hormone and neurotransmitter?
Hormone travel in bloodstream and secreted by endocrine gland. - long distance
Neurotransmitter - travel across synaptic cleft, secreted by neuron - short
BOTH: bind to a rececptor on a cell
What is a neurohormone?
a hormone secreted into blood by neuroendocrine cells (neurons)
What are the 2 main classes of hormones? Examples?
- amino acid based
- amines: epinephrine, norep (deriv of tyrosine), depamine, thyroid
- Peptide: insulin, GH - Lipid based
- Steroids: etrogen, testosterone, cortisol
How do the 2 classes of hormones behave differently
how they travel in blood, how target. cells recognize/receive, half life
Are amino acid based hyrdophobic or phyllic and where does it bind?
Hydrophyllic, binds on plasma membrane of target cell
Are steroid hormones hydrophobic or phyllic, where do they bind?
Hydrophobic — pass thru plasma membrane and bind in the cytosol in the nucleus of target cells
Both steroid and peptide horomones trigger a ________ response. Steroid horomone usually involve modification of…
INTRAcellular response, gene expression
How are hormones eliminated?
- Taken up by target cell
- Broken down (metabolized by liver) —- eliminated via kidneys
what does rate of hormone elimination depend on?
structure, and wether its bound to a carrier protein
what is hormone half life?
time taken for hormone concentration to reduce by half in the blood
Are hydrophobic/phyllic horomones bound to carrier proteins? How does this effect half life?
Hydrophobic (steroids) are bound to carrier proteins (albumin) so they have longer half lives (min–hrs)
What are 3 ways that hormone secretion is regualted
Other horomones, other molecules (eg ca), glucose (glucose uptake by pancreatic cell triggers insulin secretion, neurotransmitters (symp neurons trigger epinephrine, norepinephrin)
Where do the horomones produced in the hypothalamus go? What is directed in the hypothalamus?
to the post. pit, directs horomones from ant pit
What 2 horomones does hypothal produce for secretion by___
post pit: anti-diuretic horomone (ADH) – to kidneys – water reabsorption back into blood
Oxytocin – uterus and mammary gland: uterine contraction and milk release
What type of horomones (made by hypothalamus) trigger release from the ant pit?
TROPIC - a hormone that triggers release of another horomone
What are 5 tropic horomones released by hypothalamus?
thyroid releasing hormone, corticotropin releasing hormone, prolactin releasing hormone, gonado-tropin releasing horomone, GH releasing hormone
what does prolactin releasing horomone lead to?
prolactin releasing hormone — prolactin — mammary gland –milk production
what is the path of thyroid releasing hormone?
thyroid releasing hormone — thyroid stim hormone – thyroid gland ( thyroid stim and secretion)
Path of corticotropin releasing hormone?
triggers adrenocorticotropic horomone then to adrenal cortext which secretes cortisol and aldosterone