Slide 1Slide 2Chemical signals coordinate body functionsChemical signals coordinate body functionsSlide 5Slide 6Slide 7Slide 8Slide 9Slide 10Slide 11Slide 12Slide 13Slide 14Slide 15Slide 16Slide 17Slide 18Slide 19Slide 20Slide 21Slide 22Slide 23Slide 24Slide 25Slide 26Slide 27Slide 28The thyroid regulates development and metabolismSlide 30The thyroid regulates development and metabolismSlide 32Hormones from the pancreas maintain glucose homeostasisSlide 34Slide 35Slide 36CONNECTION: Diabetes is a common endocrine disorderCONNECTION: Diabetes is a common endocrine disorderSlide 39Slide 40Slide 41The adrenal glands mobilize responses to stressSlide 43The gonads secrete sex hormonesThe gonads secrete sex hormonesSlide 46Slide 47Slide 48Slide 49Slide 50Slide 51Slide 52BIOL 003: Organisms in Their EnvironmentLecture #11– Endocrine SystemPhoto by Sarah WolakThe Endocrine System• Chemical communication system• Important in coordinating whole-body functions– Reproduction– Growth & development– Metabolism– Response to stressChemical signals coordinate body functions The endocrine system–consists of all hormone-secreting cells–works with the nervous system in regulating body activities.Comparing the endocrine and nervous systems–The nervous system reacts faster.–The responses of the endocrine system last longer.Chemical signals coordinate body functions Hormones are–chemical signals,–produced by endocrine glands,–usually carried in the blood, and–responsible for specific changes in target cells.Hormones may also be released from specialized nerve cells called neurosecretory cells.Neuron Neurosecretory cell Endocrine cellEndocrine System vs. Nervous SystemHormones affect target cells using two main signaling mechanismsTwo major classes of molecules function as hormones in vertebrates.–The first class includes hydrophilic (water-soluble), amino-acid-derived hormones–proteins–peptides–amines–The second class of hormones are steroid hormones–small, hydrophobic molecules made from cholesterol.–e.g., sex hormonesHormones affect target cells using two main signaling mechanismsHormone signaling involves three key events:–reception,–signal transduction, and–response.Hormones affect target cells using two main signaling mechanismsAn amino-acid-derived hormone–binds to plasma-membrane receptors on target cells and–initiates a signal transduction pathway.Figure 26.2A_s1Water-solublehormoneTarget cellReceptorproteinPlasmamembraneNucleus1Interstitial fluidFigure 26.2A_s2Target cellReceptorproteinPlasmamembraneNucleus1Interstitial fluid2SignaltransductionpathwayRelaymoleculesWater-solublehormoneTransduce – “to lead across”Figure 26.2A_s3Target cellReceptorproteinPlasmamembraneNucleus1Interstitial fluid2SignaltransductionpathwayRelaymoleculesCellular responsesorGene regulationCytoplasmicresponse3Water-solublehormoneHormones affect target cells using two main signaling mechanismsA steroid hormone can–diffuse through plasma membranes, –bind to a receptor protein in the cytoplasm or nucleus, and–form a hormone-receptor complex that carries out the transduction of the hormonal signal.Figure 26.2B_s1SteroidhormoneTarget cellNucleus1Interstitial fluidFigure 26.2B_s2SteroidhormoneTarget cellNucleus1Interstitial fluid2ReceptorproteinFigure 26.2B_s3SteroidhormoneTarget cellNucleus1Interstitial fluid2Receptorprotein3Hormone-receptorcomplexDNAFigure 26.2B_s4SteroidhormoneTarget cellNucleus1Interstitial fluid2Receptorprotein3Hormone-receptorcomplexDNA4TranscriptionmRNANew proteinCellular response:activation of a gene and synthesisof new proteinTHE VERTEBRATE ENDOCRINE SYSTEM© 2012 Pearson Education, Inc.Figure 26.3Thyroid glandParathyroid glands(embedded withinthyroid)ThymusAdrenal glands(atop kidneys)PancreasTestes(male)Ovaries(female)HypothalamusPituitary glandThe vertebrate endocrine system consists of more than a dozen major glands Some endocrine glands (such as the thyroid) primarily secrete hormones into the blood.Other glands (such as the pancreas) have–endocrine and–non-endocrine functions.Table 26.3_1Table 26.3_2The hypothalamus, which is closely tied to the pituitary, connects the nervous and endocrine systemsThe hypothalamus (“master control center”)–connects the nervous and endocrine systems–receives input from nerves about the internal conditions of the body and the external environment–responds by sending out appropriate nervous or endocrine signals–uses the pituitary gland to exert master control over the endocrine systemFigure 26.4ABrainHypothalamusPosterior pituitaryAnterior pituitaryBoneThe hypothalamus, which is closely tied to the pituitary, connects the nervous and endocrine systemsThe posterior pituitary–is composed of nervous tissue–is an extension of the hypothalamus–stores and secretes oxytocin and ADH, which are made in the hypothalamus.–Oxytocin = “love hormone”–ADH = antidiuretic hormone; increases water retentionFigure 26.4BHypothalamusNeurosecretorycellAnteriorpituitaryHormonePosteriorpituitaryBloodvesselUterine musclesMammary glandsKidneytubulesADHOxytocinHow do these differ from neurotransmitters?The hypothalamus, which is closely tied to the pituitary, connects the nervous and endocrine systemsThe anterior pituitary–synthesizes and secretes hormones that control the activity of other glands–is controlled by two types of hormones released from the hypothalamus:–releasing hormones stimulate the anterior pituitary–inhibiting hormones inhibit the anterior pituitaryFigure 26.4CNeurosecretorycell of hypothalamusEndocrine cells ofthe anterior pituitaryPituitary hormonesBlood vesselReleasing hormonesfrom hypothalamusThyroidTSHProlactin(PRL)AdrenalcortexTestes orovariesFSHandLHMammaryglands(in mammals)Growthhormone(GH)ACTHEntirebodyEndorphinsPainreceptorsin the brainHypothalamus secretes releasing and inhibiting hormones - to anterior pituitaryHORMONES AND HOMEOSTASISThe thyroid regulates development and metabolismThe thyroid gland is located in the neck, just under the larynx (voice box).The thyroid gland produces the hormone thyroxineWhich regulates many aspects of–metabolism–reproduction–developmentHyperthyroidism – overproduction of thyroxine  overactive metabolism, high blood pressureFigure 26.4EHypothalamusAnteriorpituitaryThyroidThyroxineInhibitionInhibitionTRHTSHNegative Feedback LoopThe thyroid regulates development and