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學習快評丨qibao666888　　嬰??(ying)幼??(you)兒??(er)期??(qi)(0～3歲??(sui))??，新??(xin)生??(sheng)兒??(er)免??(mian)疫??(yi)系??(xi)統(tǒng)??(tong)像??(xiang)一??(yi)支??(zhi)未??(wei)經(jīng)??(jing)實?(shi)戰(zhàn)??(zhan)的??(de)“新??(xin)兵??(bing)部??(bu)隊??(dui)”??，先??(xian)天??(tian)性?(xing)免??(mian)疫??(yi)(如??(ru)中??(zhong)性??(xing)粒??(li)細??(xi)胞??(bao)、巨??(ju)噬??(shi)細??(xi)胞??(bao))活??(huo)性??(xing)高??(gao)??，但??(dan)皮??(pi)膚??(fu)、黏??(nian)膜??(mo)屏??(ping)障??(zhang)薄?(bo)弱??(ruo)??，易?(yi)受??(shou)病??(bing)毒??(du)(如??(ru)呼??(hu)吸??(xi)道??(dao)合??(he)胞?(bao)病??(bing)毒??(du)、輪??(lun)狀??(zhuang)病??(bing)毒??(du))侵??(qin)襲??(xi)??。??此??(ci)時?(shi)主??(zhu)要??(yao)依??(yi)賴??(lai)母??(mu)體??(ti)通??(tong)過??(guo)胎??(tai)盤??(pan)和??(he)母??(mu)乳??(ru)傳??(chuan)遞??(di)的??(de)抗??(kang)體??(ti)(如??(ru)IgG、IgA)提??(ti)供??(gong)保??(bao)護??(hu)???！　??(er)童??(tong)至?(zhi)青??(qing)少??(shao)年??(nian)期??(qi)(4～18歲??(sui))??，隨??(sui)著?(zhe)免??(mian)疫??(yi)系??(xi)統(tǒng)??(tong)逐?(zhu)漸??(jian)成??(cheng)熟??(shu)??，適?(shi)應??(ying)性??(xing)免?(mian)疫??(yi)(T細??(xi)胞??(bao)、B細??(xi)胞??(bao))開?(kai)始?(shi)發(fā)??(fa)揮??(hui)主??(zhu)力??(li)作??(zuo)用??(yong)??，能?(neng)針??(zhen)對?(dui)病??(bing)原??(yuan)體??(ti)產(chǎn)??(chan)生??(sheng)特??(te)異??(yi)性??(xing)抗??(kang)體??(ti)??。??但??(dan)免??(mian)疫??(yi)系?(xi)統(tǒng)??(tong)也??(ye)可??(ke)能??(neng)因??(yin)“經(jīng)?(jing)驗??(yan)不??(bu)足??(zu)”而?(er)反??(fan)應??(ying)過??(guo)度??(du)??，如??(ru)對??(dui)花??(hua)粉??(fen)、食??(shi)物?(wu)等??(deng)無??(wu)害??(hai)物??(wu)質(zhì)?(zhi)過??(guo)度??(du)反??(fan)應??(ying)??，引??(yin)發(fā)??(fa)哮?(xiao)喘??(chuan)、濕??(shi)疹??(zhen)；如??(ru)接??(jie)觸??(chu)外??(wai)界??(jie)增??(zeng)多??(duo)??，易??(yi)感??(gan)染??(ran)手??(shou)足??(zu)口??(kou)病??(bing)、水??(shui)痘??(dou)等??(deng)傳??(chuan)染??(ran)病??(bing)??。。