Endocrine system Flashcards
what is direct communication
exchange of ions/molecules between adjacent cells via gap junctions
what is direct communication between
2 of the same cell
what is paracrine communication
chemical signals from cell to cell within the same tissue (both are PARt of a tissue)
what does transmission occur via
extracellular fluid
what is autocrine communication
occurs within itself
what is endocrine communication
releases hormones that are then transported to the blood stream
what is the definition of a hormone
chemical that controls and regulates cell or organs
what is endocrinology
study of hormones and endocrine organs
what is the tissue of endocrine and exocrine glands
glandular epithelium
what do exocrine glands do
release contents that leads to surface
what is merocrine
top of the cell releases contents by exocytosis (just the tip before marriage)
what is apocrine
part of the cell is pinched off/half gets torn away (apo = away)
what is halocrine
entire cell ruptures (in halo, when you shoot someone, they explode)
what are the 3 classes of hormones
amino acid, peptide hormone, lipid
what are 2 amino acid derivatives
tyrosine and tryptophan
what are peptide hormones synthesized as
prohormones
are peptide hormones short or long
short
are protein hormones short or long
long
what are 2 examples of polypeptide hormones
ADH and OXT
what are 2 examples of protein hormones
insulin and prolactin
what type of hormone is elcosanoids
lipid derivative
what do elcosanoids do
coordinate cellular activity and enzymes
what has contrasting effects on blood clots
omega 3 and 6
what are steroid hormones derived from
cholesterol
what steroid hormone do testes produce
androgens
what steroid hormone do the ovaries produce
estrogen and progesterone
what steroid hormone does the adrenal cortex produce
corticosteroid
what steroid hormone does the kidneys produce
calcitrol
what do steroid hormones bind to
transport proteins in plasma
are catecholamines and peptide hormones lipid soluble
no
where do catecholamines and peptide hormones bind to receptors
outside of membrane
are steroid and thyroid hormones lipid soluble
yes
where do steroid and thyroid hormones bind to receptors
inside of cell/membrane
what 2 things can hormones do in the blood
circulate freely and bind to carrier proteins
how long are free hormones functional
less than an hour
do bound hormones or free hormones remain functional longer
bound
when do free hormones become inactivated
diffuse out of blood and bind to receptors; absorbed by kidneys/liver; broken down by enzymes
what does the hormone in G protein coupled receptors use to activate the protein
intermediary
what happens once G protein is activated
cAMP levels increase
what is the secondary messenger
cAMP
what does activation of secondary messengers cause
accelerates metabolic activity
what does G protein inhibitory effect cause
decrease in cAMP levels
what does G protein activate to cause production of hormones
PLC
what hormones does the activation of PLC cause in secondary messengers
DAG and IP3
what does DAG and IP3 come from
PIP2
what diffuses into the cytoplasm in secondary messengers
IP3
what is released when IP3 is released into the cytoplasm
calcium
what does calcium activate in secondary messengers
PKC
how can steroid hormones affect DNA
alter DNA transcription
what else can steroid hormones alter other than DNA transcription
enzyme synthesis
where do thyroid hormones bind to receptors
mitochondria
what 3 things occur when thyroid hormones bind to receptors in the mitochondria
activates genes, increases ATP production, and nutrient breakdown
what happens to hormone receptors during down-regulation as there is a presence of hormone
they decrease
what happens to cell sensitivity as hormone levels increase
cell becomes less sensitive (it gets used to the hormones)
what happens to hormone receptors during up-regulation as there is an absence of hormones
they increase
what happens to cell sensitivity as hormone levels decrease
cell becomes more sensitive (in hopes of one attaching)
what is humoral stimuli
change in concentration
what is hormonal stimuli
arrival/removal or hormone
what is neural stimuli
neurotransmitters
what kind of stimuli is blood Ca2+ levels
humoral
what kind of stimuli is low TH releasing TRH
hormonal
what kind of stimuli is OXT
neural
how is the pituitary gland connected to the hypothalamus
infundibulum
what are the dark stains of the anterior lobe
grandular
what kind of hormone is cAMP
peptide
where are cell bodies of the posterior lobe neurons located
hypothalamus
where is the axon of the posterior lobe neurons located
infundibulum
what does SON release
ADH
what does PVN release
OXT
what is the function of hypophyseal portal system
ensures hormones reach cells in anterior pituitary before entering circulation
what is blood flow like in hypophyseal portal system
unidirectional
what does OXT stimulate
contractions and dilation
when are receptors more sensitive during pregnancy
at the end
what system causes the release of OXT
positive feedback system
what hormone is necessary for milk ejection
oxytocin
what hormone contributes bonding and feelings of love
oxytocin
what is the main thing that ADH causes
lack of urination
what in the hypothalamus triggers ADH release
osmoreceptors
what is the osmolarity levels that cause ADH to be released
increased
how does ADH raise blood pressure
blood vessels contract
how does alcohol effect ADH
it inhibits it –> seal broken
what is diabetes insipidus
chronic dehydration
how do ADH levels affect water reabsorption in kidneys
increased ADH levels, decreases water reabsorption in kidneys
what hormones are neurotransmitters
OXT and ADH
what is the general order of how FLAT hormones are secreted
releasing hormone –> stimulating H –> act on gland –> acts on cell
what is the general order of how PIG hormones are secreted
RH and IH –> stimulating H –> act on gland
