Endocrine Physiology Flashcards
information from endocrine physiology
What hormones are essential for life?
Aldosterone
Cortisol
Insulin
Parathyroid hormone (PTH)
What are the types of endocrine secretion? and what hormone is secreted?
Neurosecretion
paracrine
autocrine
exocrine - protein
What are the classes of hormones?
- peptide
- amine
- steroid
Catacohlamines and thyroid hormones belong to which class of hormones?
amine
What amino acid are amine hormones derived from?
tyrosine
Where are the amine hormones secreted from?
T3, T4 - thyroid gland
Epi and norepi - adrenal medulla
dopamine - hypothalmic cells
Why are steriod hormones lipid soluble?
synthesized from cholesterol
what are the 2 types of amin hormones?
- catecholamines (epi, norepi, dopamine)
2. thyroid (T3,T4)
Which hormones do NOT permeate membraones?
peptide and catecholamines of the amine hormones
which hormones permeate readily?
Thyroid hormones of amine hormones
steroid hormones
what type of solubility do peptide and catecholamines have?
low lipid solubility
high water solubility (very soluble in blood)
Where are peptide hormones synthesized?
ER and golgi
where are catecholamines synthesized?
chromaffin cells
facts about catecholamines
synthesis in chrmaffin cells cytoplasm and granules
stored in granules
ACh (preganglionic nerves) causes release into blood
What zones of the adrenal gland are the following release from:
- Aldosterone
- cortisol and androgens
- Epi and norepi
- Aldosterone - glomerulosa
- cortisol and androgens - fasciulata
- Epi and norepi - medella
Since peptide hormones and catecholamines are H20 soluble, how do they diffues into cells?
bind to membrane receptors by weak, hydrophobic and electrostatic interactions
how quickly does target cell respond to release of peptide hormones and catecholamine hormones?
with seconds
how to peptide and catecholamine communicate with 2nd messengers in the cell
G protein
tyrosine kinase or
JAK kinase
Where are the G protiens and effoctor proteins?
cell membrane
What breaks down cAMP in the cytosol, cause cAMP to terminate actions?
phosphodiesterase (breaks it down to AMP)
peptide hormones and catecholamines produce _________ responses in their target cells
phasic
why does hormone concentration in blood fall?
inactivated by liver and kidney
What enzyme is associated with chanel closing?
Phosphatase
Why is cell response short lived when calcuim is released from the ER into the cytoplasm of the cell?
plasma membrane pumps Ca ions out of the cell (no longer available to bind with Ca modulin)
what 2nd messengers does the effector protein, phospholipase C activate?
DAG - diacylglycerol
IP3 - inositol triphosphate
2nd messenger cGMP is associated with which effector protein?
guanylate cyclase
where is T3 and T4 synthesized?
follicular cells
what componds interact to make T3 & T4
T3 = MIT + DIT T4 = DIT + DIT
What hormones stimulates the actions of follicle cell to make T3,T4?
TSH - thyroid stimulating hormone
True or False. Lipid soluble steroid hormones are not stored in the endocrine cell, they diffuse directly into the blood.
true
Steroid hormones are synthesized from what?
cholesterol (converted to pregenolone then..)
What do steriod and thyroid hormones bind to in blood?
plasma PRO ( globulins and albunin)
True or False. only BOUND hormone is able to enter cell and interact with receptors of target cells
false. (free hormone)
Steroid hormone receptors are located where in relation to the cell?
in the cell. (DNA transcription altering)
Genes that are upregulated by steroid or thyroid hormones increase what functions?
increase:
- ion transport
- metabolism
- cell size/tissue mass
True or False: ALL peptide hormones also possess the capability of stimulating protein synthesis
False – MOST peptide hormones
True or False. All hormones are cleared from the blood, primarily by the liver, kidney, secondarily by the target cell
True
characteristics of Cell response to hormones
- saturation
- potentation
- permissiveness
what occurs with a permissive cell response?
example
cortisol must synthesize some cell proteins before epinephrine can produce a response
TSH is secreted from where?
thyrotropes of anterior pituitary gland
what types of tissue are effected by the pituitary gland
anterior pituitary = glandular
posterior pituitary = neural
What stimulates antior pituitary to release hormones?
hypothalmus via thyrotropin releasing hormone
Which hypothalmus hormone inhibits growth hormone?
somatostatin
Which hypothalmus hormone inhibits prolactin?
dopamine
