內分泌系統 -6

腎上腺 A DRENAL G LANDS 2  Paired organs that cap the kidneys.  Each gland consists of an outer cortex and inner medulla.  Adrenal medulla:  Derived from embryonic neural crest ectoderm (sympathetic ganglia).  Synthesizes and secretes:  Catecholamines (mainly epinephrine but some norepinephrine).

腎上腺 A DRENAL G LANDS 3

腎上腺皮質的功能 Functions of the Adrenal Cortex  Does not receive neural innervations.  Must be stimulated hormonally.  Consists of 3 zones:  Zona glomerulosa:  Aldosterone: regulate Na + and K + balance.  Zona fasciculata:  Cortisol: regulate glucose metabolism.  Zona reticularis:  Androstenedione and DHEA: supplement sex steroids. 4

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腎上腺髓質的功能 Functions of the Adrenal Cortex  Innervated by sympathetic nerve fibers.  Increase respiratory rate.  Increase heart rate, cardiac output; and vasoconstrict blood vessels, thus increasing venous return.  Stimulate glycogenolysis.  Stimulate lipolysis. 7

來自神經外胚層 – 交感神經節後 腎上腺素 epinephrine 正腎上腺素 norepinephrine 8

壓力與腎上腺 Stress and the Adrenal Gland  一般適應症候群 ( General Adaptation Syndrome, GAS) Stress stimulates pituitary-adrenal axis Alarm phase 警告反應期 : –Adrenal glands activated. Stage of resistance 抵抗期 : –Stage of readjustment. Stage of exhaustion 耗劫期 : –Sickness and/or death if readjustment does not occur. 9