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25 Cards in this Set
- Front
- Back
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Receptors and intracellular messengers....
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woiannfe
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How many chemical messengers are there and name them.
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6 total.
Neurotransmitters endocrine hormones neuroendocrine hormones paracrines autocrines cytokines |
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Neurotransmitters are released from?
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axon terminals into synaptic junctions
-they act locally |
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Endocrine hormones are secreted by?
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glands or specialized cells into the blood.
-they affect target cells somewhere else in the body. |
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neuroendocrine hormones are secreted by?
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neurons
- affect target cells in a diff location in the body |
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Paracrines are secreted by?
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cells into ECF
affect neighboring cells of a different type |
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Autocrines are secreted by?
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cells into ECF
-affect function of the same cell that produced them. |
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Cytokines are?
Function as? |
peptides secreted by cells into ECF
-fxn as autocrines, paracrines, or endocrine hormones |
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Mechanism of hormone action-
First step? |
hormone binds receptor site at target cell (membrane, cytoplasm, or nucleus
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then it initiates?
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a cascade reaction in the cell
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Mechanisms of hormone action-
Cells must have a receptor specific to a hormone because? are the # of receptors constantly changing? |
if not that hormone will not have an effect on that specific cell
-yes |
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Hormone receptor complex forms-
activated receptors initiate hormonal effects via what methods? |
1. Ion channel-linked receptors
2. G protein linked hormone receptors 3.Enzyme linked receptors 4. intracellular hormone receptors and activation of genes (slower process) |
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hormone binding site located?
Enzyme/catalytic site bound? |
extracellulary
-intracellularly |
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Second messenger mechanism-
Hormones bind receptors causing? |
activation of second messenger.
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2nd messngers are?
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cAMP/ Ca2+, calmodulin
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Adenylyl Cyclase-cAMP 2nd messenger system-
hormone bind receptor, receptor then couples with? |
G protein
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Activating protein stimulates?
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adenylylcyclase
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Examples of outcomes in different cells are?
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muscle contractions, secretions, altered cell permeability
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Cell membrane phospholipid 2nd messenger system-
hormone binds receptor that activates_______ (located on inside of receptor. |
phospholipase C
-g protein linked -catalyzes breakdown of phospholipids in cell membrane. |
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phospholipase C creates 2 different 2nd messengers, what are they?
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IP3- inositol triphosphate, mobilizes Ca2 from Er to mitochon
-DAG, diacylglycerol precursor for prostaglandins |
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Calcium-calmodulin 2nd messenger system-
Ca2 enters via? |
voltage gated chennels or hormone receptors
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Ca2+ binds calmodulin. how many sites?
when 3-4 sites are bound calmodulin... |
4 sites
-changes shape |
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Steroid hormones and genetic function-
Steroid hormone diffuses across the? |
cell membrane
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Binds specific receptor protein, combines receptor-hormone complex which is?
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transported or diffuses in nucleus
or hormone binds receptor on nucleus activating transcription factors |
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Combo binds specific portions of DNA and activates?
mRNA diffuses into cytoplasm and promotes? |
transcription to form mRNA.
transcription of proteins at ribosomes |
