Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
48 Cards in this Set
- Front
- Back
|
What is the major class of hormones?
|
protein/peptide hormones
GH, PTH, Insulin |
|
|
What do amine hormones come from? what two glands secrete them?
|
these are derived from tyrosine
they come from the adrenal medulla and the thyroid gland |
|
|
what are steroid hormones derived from? some examples?
|
these are all derived from cholesterol
-cortisol, aldosterone, estrogen, testosterone, vitamin D (from 7-hydroxycholesterol) |
|
|
What are the 4 Glycoproteins?
|
FSH
TSH LH hCG |
|
|
What is the solubility and transport of catecholamines (amine/tyrosine derived) and peptides?
|
these are both hydrophilic, and transported dissolved in the blood (so they act extracellularly)
|
|
|
what is the solubility and transport of thyroid and steroid hormones?
|
these are hydrophobic, and transported bound to proteins (this also makes them lipophilic)
|
|
|
What are the main stages of peptide hormone synthesis?
|
mRNA makes preprohormone->
sent to ER, cleaved to Prohormone_> packaged by golgi, then in the secretory vesicles, it gets chopped again, and becomes a hormone |
|
|
What stimulates the release of peptide hormones?
|
an increase in cytosolic cAMP and Ca2+
this starts exocytosis |
|
|
What aer the main stages of catecholamine synthesis?
|
this starts with tyrosine
SNS activates synthesis in adrenal medulla synthesis occurs in the cytosol catecholamines are stored in granules, mostly made up of EPI |
|
|
What are the main stages of thyroid hormone synthesis?
|
these are derived from tyrosine as well.
Requires IODIDE. this incorporates IODIDE into the tyrosine in the follicles. synthesis can occur intra/extraceullarly. But stored in follicle makes T4, T3, rT3 |
|
|
What are steroid hormones made from? where are they synthesized? are they stored?
|
these are all made from cholesterol in the specific organ that needs them
not stored |
|
|
What hormones come from the zona fasciulata?
|
cortisol
corticosterone |
|
|
what hormones come from the zona glomerulosa?
|
aldosterone
|
|
|
what hormones come from the zona reticularis?
|
androstenedione
|
|
|
What 3 hormones are released as Prohormones and then converted somewhere else into their active form??
|
Vitamin D3-> 1,25 dihydroxyvitamin D3
Testosterone-> DHT (or Estradiol) Thyroxine T4 -> Triiodothyronine T3 |
|
|
What 3 kinds of outcomes can peripheral conversion of hormones create?
|
more active hormone
less active hormone or different class of hormone |
|
|
What cause humoral secretion of hormones?
|
this is activated by blood born substrate-
looks for concentration of a substance being above or below a set point |
|
|
What causes neural secretion of hormones?
|
extension of the CNS that can be affected by psychic, emotional stimuli.
-i.e, shock, exercise, stress |
|
|
How are peptides transported in the blood?
|
these are hyrophilic- transported dissolved in plasma
|
|
|
how are catecholamines transported in the blood?
|
these are hydrophilic
50% are dissolved in plasma 50% are bound to albumin |
|
|
how are steroids and thyroid hormones transported in the blood?
|
these are hydrophobic
only circulate bound to plasma proteins -can be nonspecific binding to albumin -or specific binding to globulin (thyroxine, testo, coritcosteroid) |
|
|
What are the four effects of binding proteins to transport hormones?
|
these increase the half life of hormones in the plasma
they provide a reserve release pool for hormones it keeps the hormone inactive when bound influences the rate of hormone turn over |
|
|
What are the hydrophilic hormones? what kind of receptor do they use?
|
the hydrophilic hormones are peptides and catecholamines.
these use a receptor or channel on the cell surface |
|
|
what are the hydrophobic hormones? what kind of receptors do they use?
|
these are thyroid hormones and steroid hormones.
these diffuse through the lipid bilayer and bind to the nuclear receptors |
|
|
What is the method of action for steroid hormones/thyroid hormones?
|
these travel in the blood bound to proteins. they they diffuse throught the cell wall, and eventually into the nucleus
here they bind steroid hormone receptors in nucleus. the receptor/hormone complex binds to DNA that then activates or suppresses genes. (these can also bind to membrane receptors that use 2nd messenger systems) |
|
|
What part of the nuclear receptor does the hormone bind to?
|
the E domain
|
|
|
what part of the nuclear receptor binds the DNA?
|
then C domain- with its 2 zinc fingers
|
|
|
What are the components of the Steroid responsive element?
|
H bound to a receptor, then dimerizes (two H-R's)
the Hormone-Receptor complex binds to DNA- this is the SRE |
|
|
What are some common hormones that use cAMP 2nd messenger systems?
|
ACTH
LH FSH TSH ADH CRH PTH calcitonin glucagon |
|
|
what are some common hormones that use PLC 2nd messengers?
|
TRH
angiotensin 2 ADH oxytocin |
|
|
What are some common hormones that use tyrosine kinase receptors?
|
insulin
IGF |
|
|
what are some common hormones that use cGMP 2nd messengers?
|
ANP
EDRF NO |
|
|
what are some common hormones that use steroid hormone receptors?
|
androgens
glucocorticoids aldosterone thyroid hormones vitamin D |
|
|
what is the most common feedback mechanism?
|
negative feed back
|
|
|
What are the common neural mechanisms of hormone release?
|
sudden increase in hormonal output
like epi from the adrenal medulla |
|
|
what are the diurnal rhythms of hormones?
|
these are patterns of pulsation of hormone release
|
|
|
what regulates the rate of production of hormones?
|
this is regulated by feedback mechanisms
|
|
|
what regulates the rate of delivery of hormones?
|
blood flow
|
|
|
What is the threshold on a D-R curve?
|
this is the minimal concentration of a hormone required to achieve a response
|
|
|
what is the maximal response of a D-R curve?
|
this is where extra hormone release has no extra effect
|
|
|
what is the sensitivity of a D-R curve?
|
this is gauged by the concentration of a hormone that produces 50% of the maximal response.
if needs more hormone, it is less sensitive than before |
|
|
What things can cause a reduction in the maximal response of a hormone?
|
Less target cells
less receptors lower activity in signal transduction enzymes |
|
|
what causes a reduction in the sensitivity of a hormone?
|
a decrease in hormone-receptor number
decrease in hormone-receptor affinity |
|
|
What can cause down regulation, affecting maximum response or sensitivity?
|
there is a decrease in the number of receptors, or affinity for a hormone.
this can be done to reduce the sensitivity of a target when hormone levels are high for an extended time |
|
|
what is autologus up/down regulation?
|
this is where a hormone regulates its own receptor
|
|
|
what is heterologous regulation?
|
this is where a hormone regulates another hormones receptor
|
|
|
what is synergism?
|
this is where the effect of two hormones together is greater than the sum of their parts
|
|
|
what is permissiveness?
|
this is where one hormone must be present to exert the full effect of another hormone
|
