endocrine system Flashcards
what is the purpose of the endocrine system
maintain homeostasis
integrate nervous and immune systems with other bodily systems
what are the 3 types of endocrine pathologies
hypersecretion, hypo secretion, receptor or secondary messenger defects
what do hormones control
growth and development
metabolism
internal environment regulation (water, ions, electrolytes, temp)
reproduction
how to hormones act on targets
alter rate of enzymatic reactions
transport of molecules across cell membranes
gene expression, protein synthesis
what can hormone solubility determine
receptor location
transportation in plasma
length of actions
what type of hormones are lipid soluble
steroids, thyroid amines
what physical feature of a molecule indicates that it is a steroid
benzine ring (circle inside a hexagon)
Where are steroid receptors usually located
cytoplasm, nucleus
describe peptide hormone synthesis and storage
made in advance, stored in secretory tissues
describe steroid hormone synthesis and storage
synthesised on demand at the adrenal cortex
how are amine hormones synthesised and stored
synthesised in the adrenal medulla and stored in secretory vesicles
If a hormone is lipid insoluble how does it move in the blood
dissolved in plasma
if a hormone is lipid soluble how does it move in the blood
bound to protein carrier molecules
if a hormone is lipid soluble, what is its half life relative to other hormones?
long
if a hormone is lipid insoluble, what is its half life relative to other hormones
short
what do lipid insoluble hormones require to act on a target cell
surface receptors+secondary messengers
which is the most common type of hormone
proteins/peptides
what does a peptide hormone require to be released from the secretory vesicle
release signal
how and where (specific structures) are peptide hormones synthesised and stored
the peptide is first synthesised by the ribosomes in the rough ER into the form of a preprohormone. Enzymes in the rough ER then chop off the signal sequence which transforms the preprohormone into a prohormone. The prohormone is then transported to the Golgi complex where more enzymes chop off peptide fragments off of the pro hormone transforming it into the final active hormone. Both fragments and the active hormone are then stored in an excretory vesicle ready to be released.
do hormones create a 1-1 effect on the target cells that it attaches to? why
no. Secondary messengers amplify the effect of hormones.
what type of hormone is insulin and what does it do
it is a peptide hormone that signals for cells to take up glucose in the blood as well as inhibiting fat breakdown
what is glucagon and what type of hormone is it
is is a peptide hormone that signals for cells to release internal glucose stores into the blood stream.
What is the importance of the glycemic index of a food
it indicates how quickly and severe the blood glucose increase from eating it is.
what tissues synthesise protein hormones
many tissues
