of the endocrine system and hormones The endocrine to secrete within system influences metabolic activity by means of hormones to excite Role of Hormones and Endocrine S ystem Reproduction ID: 1047036
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2. The Endocrine System
3. Role of the endocrine system and hormones The endocrine (to secrete within) system influences metabolic activity by means of hormones (to excite)
4. Role of Hormones and Endocrine System:ReproductionGrowth and developmentMaintain balance of bloodRegulate cellular metabolism and energy balanceMobilization of body defenses
5. Differences between the nervous system and the endocrine system? Responses to endocrine system last longer than those induced by nervous system Electrical vs chemicalMuscles/glands vs glands/cells
6. Target cells and how they are impacted by hormonesa cell that bears receptors for a hormoneHormones alter target cell activity (increase or decrease rates of normal cell activity)
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8. What changes will a hormone cause?Changes in plasma membrane permeability or electrical stateSynthesis of proteins, such as enzymesActivation or inactivation of enzymesStimulation of mitosisPromotion of secretory activity
9. How do hormones communicate with cells? Two mechanisms in which hormones actLipid-soluble hormones (Direct gene activation)Water-soluble hormones (Second-messenger system)
10. Direct Gene Activation (Steroid Hormone Action)Diffuse through the plasma membrane of target cellsEnter the nucleusBind to a specific protein within the nucleusBind to specific sites on the cell’s DNAActivate genes that result in synthesis of new proteins
11. Figure 9.1aNucleusCytoplasmSteroidhormoneReceptorproteinHormone-receptorcomplexDNAmRNANewproteinPlasmamembraneof targetcell
12. Second-Messenger System (Water-Soluble Hormone Action)Hormone binds to a membrane receptorHormone does not enter the cellSets off a series of reactions that activates an enzymeCatalyzes a reaction that produces a second-messenger moleculeOversees additional intracellular changes to promote a specific response
13. Figure 9.1bCytoplasmNonsteroidhormone (firstmessenger)EnzymeReceptorproteinSecondmessengerEffect on cellular function,such as glycogenbreakdown Plasmamembraneof target cellATPcAMP
14. Control of Hormone Release: Triggering Endocrine Gland StimuliHumoral Stimuli: when glands secrete their hormones in response to changing blood levels of critical ions and nutrientsExample: Low Ca2+ in blood: Parathyroid will secrete PTH to increase blood Ca2+
15. Neural StimuliWhen nerves stimulate hormone release Example: when body becomes stressed – nerves stimulate release of norepinephrine and epinephrine
16. Hormonal StimuliWhen glands release hormones in response to other hormonesExample: hypothalamus regulates the secretion of most pituitary hormones which then in-turn stimulates other glands
17. http://www.bozemanscience.com/endocrine-system