Age 16 Age 33 Age 52 Maurice Tillet The French Angel 57 Growth promoting and

Age 16 age 33 age 52 maurice tillet the french angel

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Age 16Age 33Age 52
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Maurice Tillet: The French Angel 57
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Growth-promoting and metabolic actions of growth hormone (GH).Hypothalamussecretes growthhormone–releasinghormone (GHRH), andGHIH (somatostatin)AnteriorpituitaryInhibits GHRH releaseStimulates GHIH releaseInhibits GH synthesisand releaseFeedbackIndirect actions(growth-promoting)Liver andother tissuesInsulin-like growthfactors (IGFs)ProduceEffectsSkeletalExtraskeletalFatmetabolismCarbohydratemetabolismDirect actions(metabolic,anti-insulin)EffectsGrowth hormone (GH)Increased cartilageformation andskeletal growthIncreased proteinsynthesis, andcell growth andproliferationIncreasedfat breakdownand releaseIncreased bloodglucose and otheranti-insulin effectsIncreases, stimulatesInitial stimulusReduces, inhibitsPhysiological responseResult58
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Thyroid-Stimulating Hormone (TSH)Stimulates the thyroid gland to secrete triiodothyronine (T3) and thyroxine (T4)Secretion stimulated by thyrotropin-releasing (TRH) from hypothalamusT3and T4blood level is a major regulator of TRH secretion59
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Thyroid Hormone FunctionsThyroid hormones affect quality of lifeHave long-term effects on metabolismAre required for normal growth and developmentAre essential for nervous system developmentThe effects of thyroid hormones are most easily seen in cases of hypersecretion and hyposecretion60
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Hyperthyroidism (Chronic High Thyroid Hormone Levels)Hyperthyroidism has dramatic effectsIncreases oxygen consumption and metabolic heat productionIncrease protein catabolism and may cause muscle weaknessHyperexcitable reflexes and psychological disturbancesInfluence -adrenergic receptors in the heart (high heart rate and force of contraction)61
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Hypothyroidism (Chronic Low Thyroid Hormone Levels)Hypothyroidism has opposing effectsSlow metabolic rate and oxygen consumptionDecreased protein synthesisEffects on the nervous system (slowed reflexes, slow speech and thought processes, and feelings of fatigue)Cretinism in infantsSlow heart rate (bradycardia)62
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HypothalamusTRHAnterior pituitaryTSHThyroid glandThyroidhormonesTarget cellsStimulatesRegulation of thyroid hormone secretion.Inhibits63
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Goiter: Hypertrophy of the Thyroid GlandGoiter is due to excessive TSH stimulation of the thyroid gland:1.In hypothyroidism, lack of negative feedback can result in high TSH levels 2.In hyperthyroidism, antibodies can mimic TSH and cause goiterFigure 23-10b64
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Goiter can Occur in Both Hypothyroidism and HyperthyroidismFigure 23-12a65
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Goiter can Occur in Both Hypothyroidism and HyperthyroidismFigure 23-12b66
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Exophthalmus: Hypertrophy of Tissues in the Eye SocketSign of hyperthyroidismFigure 23-10c67
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Follicle-Stimulating Hormone (FSH)In females: targets ovaries for monthly development of several ovarian follicles that surround a developing oocyteIn males: targets testes for production of spermSecretion stimulated by gonadotropin-releasing (GnRH) hormone from hypothalamusBlood estrogen or testosterone level is a major regulator of GnRH and FSH secretion68
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