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66 Cards in this Set
- Front
- Back
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Endocrine Glands
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-Pituitary Gland
-Thyroid & Parathyroid -Adrenal -Pancreas -Ovary & testies |
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Endocrine Tissue
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-CNS
-C-cells -thyroid -Thymus & Immunesytem --Lung -Heart -Kidney -Gastro |
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Peptide Hormones
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Slowly produced/quickly released (why?)
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peptide proteins
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stored
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hydrophilic
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peptide protein
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independent of the liver
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peptide protein
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why are peptide proteins said to be quickly destroyed
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b/c broken down by proteases in the esp in liver & kidney
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quick release/quickly destruction tells us
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short half life of peptide hormones
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what else do peptide proteins have that are unique..
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pre & pro sequences that can be active compounds too
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action mechanism for peptide hormones
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receptors for peptide hormones are found on cell membranes
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why are receptors for peptide prot. found on cell membrane?
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b/c p.proteins are hydrophilic and can NOT diffuse
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peptide proteins can/can't diffuse ?
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No..can't diffuse
-bind cell membrane -2nd mesg mechanism |
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principle of 2nd messenger mechanism is?
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-protein hormone(1st messenger)
-remains OUTSIDE of the target cell -binds to receptor on cell membrane -it transmits its message via cAMP |
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-hormone-receptor binding activates..
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so after 1st messenger binds
-another receptor subunit -activates G-protein -G-protein activates AC (adenyl Cyclase) |
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-Adenyl Cyclase (AC) converts...
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ATP-->cAMP
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cAMP increase activates
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cAMP increase activates a protein kinase which phosphorylates other enzymes
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Phosphorylation leads to
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stimulation or inhibition of these enzymes
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Second Messenger=
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cAMP
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first messenger=
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hormone
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protein hormones stay...
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outside target cell
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protein hormones transmit message how?
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via 2nd messenger mechanism (via cAMP)
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Protein hormones lead to a chain reaction, at the end of which.....(finish my sentence)
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at the end of which ENZYMES (=metabolic pathways) are either stimulated or inhibited
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Give an example of a second messenger system.
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glucagon-->
cAMP--> phosphorylation of phosphorylase--> stimulates GLYCOGEN-OL-YSIS |
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examples of other 2nd messenger systems ....
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-calmodulin sms
-Cell Membrane Phospholipids |
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back to synthesis of Protein hormones...tell me about how it occurs
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-synthesis occurs by formation of pre-pro-hormones
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pre-pro-hormones are broken down into?
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pro-hormones
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pro-hormones are
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packaged in secretory cells
-so proteins are produced in the rough ER -packaged into vesicles in the golgi apparatus |
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General characteristics;
Hormones are...... (NOTE THAT now I'm asking about hormones in general..not specifically protein hormones..) |
chemical messengers
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What are the chemical classes of hormones
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-Peptide/Protein hormones
-Steroid Hormones -Amines=Tyrosine derived -Eikosanoid Hormones |
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Which two are hydrophilic
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-Peptide hormones
-Eikosanoid Hormones |
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If I say Peptide Hormones you think..
(clue "P's"...) |
-Pancreatic Hormones
-many hyPothalamic hormones -most Pituitary gland hormones -Parathyroid Hormones |
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ALL hormones affect their target tissue by.....
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forming 1st a HORMONE/RECEPTOR complex,which alters the activity of their target cell
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receptor locations for hydrophilic hormones (give examples of which hormones we're talking about too)
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hydrophilic=peptide & eikosanoid hormones
-receptors on Cell Membrane -can NOT diffuse |
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receptor locations for lipophilic hormones (give examples of which hormones we're talking about too)
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lipophilic=Steroids & Amines & they
CAN diffuse thru and bind with receptors in Cytoplasm or Nucleus |
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w/i cytoplasm=
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steroids (lipophilic)
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w/i nucleus=
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thyroid hormones (lipophilic)
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synthetic hormones bind to
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same receptors
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Antagonist=
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block the hormone's original action
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Agonist=
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mimic the hormone's action
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hormone's effect end after
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-dissociation from receptor
-after internalization of receptor-hormone complex -or degredation |
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Receptors are..
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-large protein molecules (consists of several subunits)
-are highly specific -have high affinity |
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Receptor numbers per target cell can.....
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they can change....
-down regulate - or upregulate |
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back to protein hormone SYNTHESIS..briefly describe steps
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stimulus to an endocrine gland cell initiates pro hormone synthesis
-ex blood glucose-->insulin -pre& pro are cleaved off leaving hormone -Hormone is stored in secretory granules(vesicles) -stored in cell membrane - |
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-Secretion of hormone (from storage) upon respective stimulation via..
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Exocytosis
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When endocrine cell is stimulated, vesicles fuse with______ finish my sentence.(still talking about protein hormone synthesis)
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When endocrine cell is stimulated, vesicles fuse with CELL MEMBRANE & hormone content is emptied & SECRETION leads to SYNTHESIS
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Tell me some things about hormones in general..
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-chemical messengers
-are physiological regulators(GMHR) -produced in endocrine/gland cells -secreted locally=Paracrine -secreted into circulation=ENDOcrine -AFFECT TARGET cells or organs -Present in VERY low concentrations |
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A cell usually contains many different receptors & is therefore a ______......
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is therefore a target cell for many different hormones (pg 200 in text)
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name some processes regulated by the Endocrine System (hint GMHR)
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-Growth
-Metabolism -Homeostasis -Reproduction |
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In negative feedback control, increased activity in the target organ will lead to (usually)
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reduced stimulation of target cells
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Hormones will only affect cells......
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possessing the correct RECEPTORS...and ALL hormones bind to receptors!
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Hypo-pituitary Thyroid Axis..
Hypothalamus is stimulated by_____ to release____ |
cold to release TRH (Thyroid Releasing Hormone
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TRH stimulates...
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Anterior Pituitary to release TSH
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TSH stimulates the ....
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Thyroid gland to release THYROID hormones (T3 T4)
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which thyroid hormone is more dominant in plasma?
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T4
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biologically active form=
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T3
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action mechanism for a steroid hormone
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diffuse into cell & bind to a receptor
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steroid hormones are derived from
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cholesterols (from diet or synthesis in the body)
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Regarding Steroid Hormones respective synthesis activates________ to lead to ______
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stimulus activates ENZYMES & leads to ----> conversion of cholesterol to steroid hormone
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Steroid Hormones are:
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-quickly produced AND released
-NO storage -are lipophilic -require transport proteins in plasma |
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what does protein binding do for the steroid hormone?
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-provides protection against quick destruction in liver
-leading to longer half life(hours to days) |
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lipophilic hormones induce_____with mostly___
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protein synthesis
-mostly with the newly formed ENZYMES |
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Initiate of protein synthesis & actual production require time...characteristic time delay of steroid hormone effect are apx...
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45 min to several hours
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Give an example of a target cell response to a lipophilic hormone
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Aldosterone (steroid) initiates synthesis of
-the enzyme ATPase in its target cells -stimulates Na/K pumps |
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Hormone effects are proportional to its________
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concentration (hormone effects need to be tightly controlled)
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Describe the internal control of a hormone...what are most hormones controlled by?
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-mostly a Negative Feedback Loop
1.Stimulus 2. Hormone production/secretion 3. Target cell response 4. Metabolic Change 5.Reduction of original Stimulus |
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example of negative feed back control loop ...use hypoglycemia
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hypoglycemia-->
-alpha (Acells) Islet of Langerhans (endocrine pancreas) & stomach secrete---> -glucagon -liver -cAMP -glycogenolysis & glucoNEOgenisis |
