Endocrinology - Receptor Mechanisms Flashcards
Neurotransmitters
diffuses through the interstitial fluid between the adjacent nerve cells
hormones
released into the blood. The blood carries them to target cells where they eleicit a physiologic response
paracrines
chemical messangers released into the intersitial fluid where they exert effects on neighboring cells
autocrines
chemical messengers released into the intersitial fluid act on the cell that secretes it
pancreatic hormones regulates
digestion
utilization
storage of nutrients
growth and thyroid hormones regulate
growth and development
ADH and aldosterone regualte
ion and water metabolism
estrogen, testosterone regulate
reproduction
why do hormones only have effects on some cells
only target cells have receptors
hiher concentration in blood to some cells
conversion to a more active form in the target tissue
permissive action of hormone
for hormone A to have its full effect, hormone B must be present, BUT hormone B does not have the effect itself
amino acid derivative hormones
Ep, NE, Dopamine, thyroid hormone
properties of amino acid derivative hormones
small
hydrophillic/lipophobic - act on cell membrane receptors - act through second messengers
stored in vesicles and released by exocytosis
thyroid hormone properties
small
hydrophobic/lipophillic (can cross membrane)
escape from cells as they are made, stored bound to plasma proteins
slow, long-term effects
Peptide and protein hormone properties
- fairly large
- string of amino acids
- short string (peptide) , long string (protein)
- hydrophillic / lipophobic
- rapid, short-term effects
steroid hormone properties
- hydrophobic / lipophilic
- act on intracellular receptors - alter gene transcription
- escape from cells as they are made
- slow, long term effects
peptide and protein hormones are formed as
larger precursor proteins that are cleaved to form the active hormone
steroid hormones are derived from
cholesterol
in steroid hormones, making proteins is __ but __
slow, long lasting
in steroid hormones, acting through second messengers is __ but __
fast, short lasting effects
steroid and thyroid hormone cant be
stored in cells because they cross membranes
steroid and thyroidhormone are stored in
the blood, bound to proteins
activation of second messenger systems
hormones that bind to cell membrane receptors
why do hormones bind to cell membrane receptors
- transfer information into the cell (lipophobic hormones can’t cross the cell membrane)
- signal amplification (more produced each step)
somatotropin
growth hormone
