l Checking (proof-reading, verifing) engineering drawings and responsible for coordinating with architect and fire control technician in context of structure, construction, electric-mechanic related work (fields);
l Designing of architecture planning (Architecture Designing and planning) , including drawing production, briefing preparation, project feasibility studies;
l Understanding the marketing (Market Survey), providing construction material related information for architects’ references;
l Conducting bidders’ and contractors’ assessment;
l Assisting customers in planning whole engineering projects’ status, including timing (scheduling) for completing all necessary details and datum at all phases;
l Instructing customers bidding operation procedures, scheduling and providing customers’ construction budgeting and capital investment preparation table;
l Analyzing Taiwan and mainland China’s cases and evaluating differences of different (both) regions for reaching the most economic and efficient suggestion to customers. They include location selection, size of the construction site, time of building etc.;
l Receiving cases through project briefing to architects and customers.


economical

how kidney works

http://health.howstuffworks.com/kidney.htm/printable

neuron stucture

Your brain is made of approximately 100 billion nerve cells, called neurons. Neurons have the amazing ability to gather and transmit electrochemical signals -- they are something like the gates and wires in a computer. Neurons share the same characteristics and have the same parts as other cells, but the electrochemical aspect lets them transmit signals over long distances (up to several feet or a few meters) and pass messages to each other.
Neurons have three basic parts:
Cell body - This main part has all of the necessary components of the cell, such as the nucleus (contains DNA), endoplasmic reticulum and ribosomes (for building proteins) and mitochondria (for making energy). If the cell body dies, the neuron dies.
Axon - This long, cable-like projection of the cell carries the electrochemical message (nerve impulse or action potential) along the length of the cell.
Depending upon the type of neuron, axons can be covered with a thin layer of myelin, like an insulated electrical wire. Myelin is made of fat, and it helps to speed transmission of a nerve impulse down a long axon. Myelinated neurons are typically found in the peripheral nerves (sensory and motor neurons), while non-myelinated neurons are found in the brain and spinal cord.
Dendrites or nerve endings - These small, branch-like projections of the cell make connections to other cells and allow the neuron to talk with other cells or perceive the environment. Dendrites can be located on one or both ends of the cell.

坐磁波椅治尿失禁 署東引進

【聯合報╱記者李蕙君／台東報導】
2009.07.27 03:02 am

署立台東醫院最近發表引進台東縣第一台座椅式體外磁波治療儀改善尿失禁，有效率達八成；該院泌尿科主任許維愷表示，最快2周至3周就有明顯效果，患者只要坐著治療，使用4次至6次、每次20分鐘，相當輕鬆。
許維愷表示，尿失禁有滿溢性、應力性、急迫性三類型，東西方體質不同，台灣人最常見為應力性尿失禁，只要咳嗽、打噴涕、突然站起來或大笑等腹壓增加，小便就不自主流出，應力性、急迫性都是可改善的症狀。
他說，目前常用的治療方式有藥物治療、凱格爾復健運動、電刺激搭配生理回饋儀、外科手術的矯正、座椅式體外磁波治療儀。
但藥物須長期服用，會引發口乾、便秘等體質差異上的副作用；凱格爾復健若認真做可達八成效果，但要長期做，持續性者不多；電刺激效果快速，且是侵入性治療，需要把探頭放到陰道或肛門內刺激，接受度低，健保也不給付；外科手術不適用所有病患，有手術風險且會復發。
座椅式體外磁波治療儀在台8年，目前是最夯的治療儀式，患者只要坐著20分鐘，看看報紙、電視等，很快就完成治療，該治療有健保給付，沒有任何已知的副作用，最快2周即見效果。老一輩患者都認為這種療效很好，願意回診治療。
【2009/07/27 聯合報】@ http://udn.com/

別忽略反式脂肪所佔據的細胞膜拖累您 !

反式脂肪吃下去馬上傷害肝臟 會破壞人體細胞膜代謝　

大明的阿姨八年前全家移民南非 , 媽媽為了讓大明和 妹妹 學英文、熟悉外國環境 , 每年暑假 , 總是讓他們到南非找阿姨。阿姨很喜歡這 2 個外甥 , 所以每天都把他們餵的飽飽的。 大明與 妹妹 剛從南非回來時 , 各胖了 3、 4 公斤 , 媽媽趕緊帶著兩兄妹來給我看診。看診的原因不是因為變胖 , 而是鼻子過敏的問題越來越嚴重 , 無時無刻都必須張口呼吸、鼻子已經完全不通了。 不但如此 , 大明的注 意力也很不集中 , 記憶力很差 , 一個月可以丟掉 3 把鑰匙 , 上課也 常被 老師點名。一問之下 , 我發現大明與 妹妹 都偏好奶製品 , 尤其是人造奶油。在南非的 2 個月 , 大明每天喝 2 大杯牛奶、幾條小乳酪 , 還喜歡在烤麵包上塗人造奶油、熱騰騰的馬鈴薯切開、加一塊人造奶油。回到台灣後 , 大明還常叮嚀媽媽要多買一些人造奶油 , 因為阿姨說人造奶油是植物油 , 對身體很好 !?

近二、三十年來 , 有越來越多的台灣人 , 受到西方飲食影響 , 以烤麵包加奶油當早餐 , 而且聽說奶油很不好 , 就改吃人造奶油。長期下來日積月累的結果 , 造成很多問題 , 例如高血壓、高血脂、心臟病、中風、各類過敏、自體免疫疾病、免疫力下降、肥胖 .....等等。

反式脂肪 / 氫化植物油是健康殺手

所謂「氫化」, 就是把植物油變成反式脂肪的過程 , 大家常吃的「人造奶油」, 就是氫化過的油。 人造奶油的製作方法 , 是在每個植物油分子理加 2 個氫原子 , 使原本順式脂肪酸變成反式脂肪酸。反式脂肪酸由於分子的極性較大 , 油分子之間的互相吸引力較強 , 所以在常溫下是固態 , 相當穩定。而原本的大豆油、玉米油這些植物油 , 在常溫下比較不穩定 , 呈液態。這就像變魔術一樣 , 液態的植物油 , 加了2 個氫之後 , 就變成固態的氫化植物油 , 然後再加點調味料 , 人工香料與色素 , 味道與模樣就跟奶油一樣了。 大家最耳熟能詳的人造奶油就是乳瑪琳。從 30 年前開始 , 台灣人就很盛行吃乳瑪琳 , 至今仍歷久不衰 , 例如 : 三明治 .... 等。另外一種氫化植物油 , 大家比較沒聽說 , 但卻更常吃 , 那就是植物性酥油 ( 俗稱白油 )。酥油是麵包師傅做麵包或餅乾時 , 幾乎都會加的油 , 以前多半是用豬油 , 現在幾乎全都用氫化植物油作成的酥油。常見如麵包、蛋糕、甜甜圈、冰淇淋等 ....及各地名產太陽餅、鳳梨酥、蛋黃酥、方塊酥、麻糬、月餅、喜餅 ...... 等等加工食品。

除此之外 , 由於氫化油不易敗壞 , 可重覆高溫油炸 , 成本低 , 使食物酥脆、賣相好 , 這種油料理時特別香 , 有很多業者都使用氫化油來油炸食物 , 例如 : 炸雞、薯條、洋芋片、餅乾、巧克力、蘇打餅、爆米花、油條、臭豆腐、鹽酥雞和素料 , 還有便利商店、大賣場架上的零食 .... 等等。要小心了 ! 您可能也在不知不覺中 , 吃下了對健康有害的氫化油。

(圖)反式脂肪問題嚴重被忽略

由於反式脂肪酸對身體的影響並非立即產生，因此人造奶油的問題一直被忽略。美國食品藥物管理局 ( FDA ) 直到 2006 年才強制要求食品包裝上必須標示反式脂肪的量，並規定反式脂肪酸限量 2 ％。然而即使是少量，對人體也可能有害。( 紐約禁用反式脂肪 2007 年七月起分階段實施 ) TIME < 時代 > 雜誌就曾公佈過 , 這種油在自然界是不存在的 , 也就是說在自然的情況下 , 人體是無法處理消化這種油脂的。 一吃下去馬上對肝臟產生傷害 , 而且還會破壞人體細胞膜，造成細胞的缺陷，影響未來的複製與再生。 當細胞膜受損或破洞時 , 細胞膜的功能就會異常無法進行「選擇性的滲透壓」, 使好的營養和氧氣滲入 , 細胞內新陳代謝的廢物排出。許多慢性病都與細胞膜不穩定有關 , 例如 : 皮膚過敏、鼻子過敏、氣喘、腸胃過敏、內分泌失調、視網膜病變、癌症 .... 等等。 巴維德 博士的油脂理論最堅持的就在此 , 她強調細胞膜不可受氫化植物油包圍缺氧而窒息 ( 癌症造成的原因之)。 脂肪酸是人體用來建造細胞膜與荷爾蒙的材料，反式脂肪酸卻是經人為氫化處理後才產生，不存在於自然界，因此人體無法處理這種油脂，只能任由其堆積於體內，進而增加罹患心臟血管疾病的機率。最近研究發現 , 氫化植物油比動物性脂肪更糟 , 會使血中壞的膽固醇增加 , 好的膽固醇減少 , 造成血管阻塞。

(圖)孕期營養影響寶寶未來的健康和家庭日後生活品質

加拿大政府健康部門於 1992 年曾做過一個實驗 , 將母奶收集起來化驗 , 發現其中有高達 7 . 2 % 的成分是反式脂肪酸 , 這表示母親本身吃了很多人造奶油、糕餅或其他氫化油。試想 , 母奶中有 7 % 是根本不能吃的氫化油 , 多麼恐怖 ! 也難怪現在有那麼多小朋友從小就有一大堆毛病。

(圖)有些幼稚園會遇怪現象--家長會問沒有在麥當勞辦生日餐會

另外 , 美國解剖各個年齡層的意外身亡者發現 , 由於從小就吃不該吃的東西 , 2 歲兒童已經開始有脂肪紋 ( Fatty Streaks ) 的現象。要知道 , 血管壁本來本來應該是光滑的 , 可是現代很多小孩的血管壁卻已經有脂肪紋 , 使血小板與壞膽固醇開始堆積 , 形成硬化斑塊 , 難怪中風年齡層會越來越低。過去 , 美國的研究向來認為油脂攝取越多 , 癌症罹患率越高 , 近幾年用更精確的統計分析 , 確進一步發現 , 原來是氫化植物油吃越多 , 癌症罹患率越高。

(圖)90% 血液在毛細血管 也要重視血液和血管的健康管理

而在台灣 , 從相關政府機構、食品加工廠、麵包糕餅店、速食店、西餐廳、一般餐廳、飯店、傳統早餐店、路邊的小販 ..... 到消費者 , 更不知道反式脂肪 ( 氫化植物油 ) 對健康有多大的影響 , 種種現象實在令人相當憂心。

反式脂肪與過敏 反是脂肪酸會造成的眾多問題 , 其中之一就是皮膚過敏。西醫對皮膚過敏沒什麼好辦法 , 只能擦類固醇或吃類固醇 , 但症狀壓下去了 , 過一陣子又發作 , 而且比上一次更嚴重。擦過類固醇的皮膚和原來的皮膚不一樣 , 照到陽光或接觸到冷熱水的反應 , 與健康皮膚大不相同 , 因此 , 自然醫學博士 陳俊旭 醫師相當反對使用類固醇。 自然醫學 陳俊旭 博士說 : 「臨床上 , 我看過太多皮膚過敏的案例。在美國時 , 我看過好幾個 [ 體無完膚 ] 的小朋友 , 全身包的密不通風 , 被小兒科醫師轉診過來 , 因為西醫已經拿他們沒辦法了。在我的觀念裡 , 皮膚過敏其實是皮膚裡面有毒素 ( 或心理壓抑 ) , 而反式脂肪就是毒素的一種。」
「皮膚裡的毒首先會讓人發癢 , 如果體內毒素累積太多 , 皮膚甚至會流汁、起疹塊或結疤。自然醫學治療皮膚過敏的原則是 , 體內與體外都要排毒 , 身心內外清爽 , 過敏就好了。」 從細胞的微觀層次來看 , 吃了壞油的人 , 它的細胞膜就是用比較多的壞油所構成 , 所以細胞膜比較不穩定 , 就容易啟動過敏反應 , 產生紅腫、流汁等現象。總之 , 不論是皮膚過敏、鼻子過敏、慢性中耳炎、氣喘 .... 等哪一種過敏 , 它們在細胞分子層面的機制都是很類似的 , 而避開毒素或避開過敏原都是最基本的方法。

(圖)氫化油或氧化油容易堵住皮脂腺形成皮膚乾燥或青春痘。

現在開始擁不嫌遲
脫胎換骨要 7 年

看到這裡 , 也許讀者會心生恐慌 , 心想已經吃這麼多年了 , 還有救嗎 ? 當然有 , 只要現在開始吃好油 , 然後逐漸把細胞膜壞油淘汰代謝掉就可以了。因為我們身體的細胞組織器官 , 一直持續著一進一出不斷新陳代謝的活動 , 今天身上這一層表皮 , 一個月後就換另一層皮了。表皮細胞代謝的週期是一個月 , 有的組織代謝比較慢 , 人體全身的細胞更新需 7 年的時間。 也就是說 , 如果原本身體不好、體質不佳、甚至罹患了癌症 , 只要有心改善 , 並能持之以恆的話 , 最晚 7 年的時間就可以脫胎換骨 , 把體質調好。

常規醫學能與不能

常規醫學治療不好的，您找他們幹什麼呢？
所以我們推薦ANDREW WEIL的書，痊癒之鑰在自己（已更名為自癒力）。YAHOO網站中另類醫學的部份就是他在負責的。他是哈佛醫學院畢業的，畢業後他到醫院去實習，發現那不是他所認知的醫學，自己還跑到了雅馬遜河流域去找古老的醫術，後來在他家的附近遇到了一位70幾歲的整骨醫師，那位老醫生家門前每天都門庭若市。他只靠幫人家調調骨頭，很多人氣喘、感冒都好了。這本痊癒之鑰在自己是ANDREW WEIL的第一本書。 裡面提到常規醫學能的和常規醫所不能的，也就是常規之學的長處和常規醫所不能醫治的。像所謂的外科系統、復健等是常規醫學的長處。而像濾過性病毒、慢性退化性疾病、大多數心理疾病自體免疫疾病或大部份的癌症，這些就是常規醫學治療不好的，那治療不好找他們幹什麼呢？

人生41歲壽命
現在的人平均壽命比較長，是因為嬰身么折的人數減少，而老一輩的人也還沒死光
我要問各位，癌症與飲食的關係這麼密切，那我們所蒐集到的資料有多少呢？像日本人就不一樣，所以他們提出來人生41歲壽命，不要說我們現在的人平均壽命比較長，那是因為嬰身么折的人數減少，而老一輩的人也還沒死光。您們可以去看看週遭的人或報紙上很多40-50歲的人是不是都有癌症，尤其是那些常常應酬的人，如歌星、影星啊，是不是？在日本有一個西丸正哉的人，他精通天文地理，研究食生態學，他認為古時候和我們現在人生理上並沒有相差很大，但古時候的人吃飯前先要去打獵，如果沒有打到，也只有摸摸肚子過一餐，即使到了農業社會，也是要先下田耕種，所以基本上古時的人是不是先運動才吃飯；而我們現在的人三頓不夠、四頓、五頓，吃完以後呢，像死屍一樣躺在那邊，所以我們在行為上是有偏差的。

小孩子年紀輕輕的也得癌症
台灣與日本差不多
如果日本社會由1959年起算，日本人的平均壽命只有41歲，因為日本在1959年，民國48年開始由歐美引進西方速食。果不其然，不要看日本，就看看我們台灣，那些得癌症的都是七老八十嗎？50歲的得，40歲的得連那些小孩子年紀輕輕的也得！！

現代化骨水
小心您小孩的骨頭腐蝕掉了
您們吃漢堡，旁邊配什麼，是不是喝可樂？陽明醫學院作了一個實驗，把蟑螂放入可樂中，經過一個禮拜，蟑螂屍體無存只剩下兩個趐膀，中興國小就拿這個來教育小孩子要多喝白開水，少喝碳酸飲料。像這個陽明大學作的實驗也不是什麼野雞大學，有沒有人告訴您們啊，沒有啊。可樂的PH值是2.2比工研醋2.4還酸。汽水、及其它的碳酸飲料是2.8，商人加了一些糖，然後給您的小孩子喝。您們知不知道可樂是用來洗豬腸的，一洗就脫了一層黏膜，那您們的小孩喝了是不是腸子也會如此。在小說裡的化骨水，就是這種，它會把人的骨頭都腐蝕掉了。是不是很像啊，對不對？
所以現在的小孩子不是營養好，是營養失調喔

更年期一定要吃荷爾蒙？
美國婦女一半在過世時是沒有子宮的
很多婦女到了更年期，就被告誡說要吃荷爾蒙，說什麼不吃會得骨質疏鬆症、糖尿病。但很多荷爾蒙的攝取造成了乳癌、子宮癌罹患率增加，所以婦女們真得是進退兩難。那我們來想想更年期少了什麼？是不是少了月經，也就是說少了一個排毒的管道，那妳還大魚大肉的往自己的血管裡面倒當然會不舒服，如果妳們吃改變得清淡一點，負擔較輕，根本不需要這些什麼荷爾蒙。尤其在美國，他們的醫學教育是怎麼教的，他們認為婦女的子宮在生完小孩以後，害怕子宮會長腫瘤，所以他們就千方百計地建議美國婦女把它拿掉。是這樣子的嗎？子宮一定會長癌症嗎？為什麼古時候的的婦女不會？就是因為這樣錯誤的教育，讓美國婦女一半在過世時是沒有子宮的。

疾病的死亡率和動物性油脂的消耗量成正比
幾十年前就已經知道了，台灣現在才知道
第一次世界大戰丹麥的進口完全的被聯軍封鎖，第二次世界大戰挪威的進口也被封鎖。當時是與循環系統疾病的死亡率戲劇性地降低了很多，此一結果使科學家們大為驚異。從圖中你們可以很清楚的看出疾病的死亡率和動物性油脂的消耗量成正比, 這個資料在幾10年前就已經知道了，我們台灣現在才知道飲食和癌症的關係。

病癥三步曲

第一步－不平衡 以均衡自然飲食調整
第二步－堆積及分泌 以飲食+內在清除法調整
第三步－內在疾病形成 以飲食+清除+心理靈性修持調整

疾病形成都有它的徵兆的。仔細看看您的位置在那裡。是在第一階段、第二階段或則是第三階段。古時有句話『引繩額而決之，其決必有處』意思是將繩子一直拉一直拉到它斷裂，它一定是會在某處斷裂的，但不確定會在什麼地方。這個故事給我們一些啟示：我們不要將我們的身體當作繩子一樣，一直給它壓力；否則它終究會有斷裂生病的一天，但我們卻不知它會生在何處；最好在繩子未斷裂之前緩緩的將它的壓力舒解掉，讓它保有最佳的彈性，以因應未來不可知的壓力。

若你檢視您自己，您的皮膚像嬰兒一樣細夕嫩夕、白裡透紅，那恭喜您！！表示您很健康，如果有其中現象也沒關係，因為當您在看這些資料時，表示一切都不會太晚。現在就慢慢讓我們仔細檢視一下：

病癥第一階段
不平衡現象

1.中度疲倦感
2.精神緊張、健忘、頭腦不清楚、無法自我放鬆
3.頭痛、肌肉緊張、局部麻木、抽痛、臠縮
4.食量突然增加、腸胃消化不良、特別喜歡甜食、高鈉
5.全身或局部發癢
6.有時候咳嗽或打噴涕
7.自感往來朝熱、朝紅或畏寒
8.易出意外狀況、不安感、挫折感、心情鬱悶
9.體重不正常增加

病癥第二階段
不正常堆積及分泌

1.呼吸時有異味、身體有異味（體臭）、口苦咽乾
2.鼻竇充血腫脹、反復咳喇打噴涕，經常感冒氣喘
3.皮膚呈現乾燥或多油膩、易起紅疹、過敏
4.身體過熱、容易出汗、手足潮濕
5.打嗝脹氣、便秘、腹瀉、嘔吐
6.女性月經痛、陰道分泌物異常、反復不斷發炎
7.反復頭痛、肌肉關節、脊柱、僵硬疼痛、慢性背痛
8.頻尿（尿色淺淡）、乏尿（尿色深紅）、刺痛、四肢腫脹
9.嚴重焦慮、恐懼、易怒、情緒不穩定、狂鬧
10.肥胖、高血脂、高血壓、高尿酸、血糖偏高
11.易出意外
12.夜臥不安寧

病癥第三階段
內在疾病形成

1.慢性消化不良、飲食不正常、進食困難、潰瘍
2.關節炎、骨質疏鬆症、痛風、退化性關節炎
3.偏頭痛、長期習慣性頭痛
4.白內障、聽力障礙、記憶力喪失
5.失眠、精神萎靡不振
6.不孕症、性生活障礙
7.糖尿病
8.持續性感染、發作
9.躁鬱症、歇斯底里症、精神分裂症
10.癌症（各種癌病變）
11.心臟血管疾病（心肌梗塞、腦中風、高血壓）
12.其他退化性疾病、免疫系統疾病、不明熱
13.成藥影響肝臟及腎臟的病變

中醫的秘訣

減少酸性的食物的攝取
那什麼是所謂的酸性食物，牛排、水煮蛋、乳酪..等都是，而鹹性的是那一些，蔬菜、水果..等都是（新世紀飲食P199）。您們去看中醫時，中醫給的是不是都是草葯（鹹性），而且是不是吩咐您們要禁口啊，那該禁的是什麼？應不是只有那一些生冷的白蘿蔔而已，應該禁的是那一些酸性的食物。

「化學蛋」
蛋是被過度誇張的食物
蛋是被過度誇張的食物，它的膽固醇相當的高。而且您們去看看現在的蛋黃是什麼顏色？是慘白的。您們可以拿去跟那些有機飼養出來的蛋比較看看，現在的蛋應該叫作「化學蛋」。（新世紀飲食P211）

吃馬鈴薯也會胖嗎？
那一些才是真正低油脂的食物
即然油脂影響我們這麼厲害，那一些才是真正低油脂的食物（新世紀飲食P260）？這裡我要提的是，您們有沒有看到「低脂牛奶」，不要被它騙了。它應該算是中油脂的食物，您們喝牛奶，照樣得心臟病、照樣得糖尿病。我們人油脂的攝取量應限定在20％以內，也就是每天20-25公克以內。那有人說吃馬鈴薯也會胖？那應該是您們吃的是炸過的馬鈴薯吧！！

「魚生火、肉生痰」
吃豆腐還不夠，還要吃個油豆腐
那一些是油脂百分之20以下的食物？基本上是青菜、水果。但並非所有的豆類都是。所以您們看我們吃豆腐還不夠，還要吃個油豆腐！另外魚也是不能天天吃，因為魚的油脂相當高。
在中醫治癌八法裡有提到「魚生火、肉生痰」，依照科學的眼光來看，我們的肝臟並不是處理油脂的地方，所以當您吃油脂較多的是不是馬上肝臟就受傷了，火氣馬上就大了。而瘦肉也是高油脂的食物，所以您們回家看媽媽水煮瘦肉是，上面是不是也浮著一層油。

顯著的平行模式
肉消耗的越多，則腸癌與心臟病的人數也越多
在1976年有一份報導，寫出了肉類與癌症的真正關係（新世紀飲食P258）。每人每年的肉消耗量與腸癌與心臟病的人數有一個很顯著的平行模式，肉消耗的越多，則腸癌與心臟病的人數也越多；也就是說，如果您們不改變飲食，還這樣大魚大肉。幸運的可以死於心臟病、心血管疾病，不然就會死於癌症。我的外公就是這樣的一個例子，本來以為是心血管疾病，後來到醫院檢查，結果是肺癌第三期。到了醫院治療時，全身都是管子，他自己覺得太痛苦，只好自己把管子拔掉。那我們回過頭來看看我們的小孩子，是不是很多現在的小孩子都不喜歡吃青菜。如果我們父母不把他們的習慣改過來，那他們以後會不會很慘啊？我怕現在吃得進去，以後他們吐不出來。

The staging of a carcinoma has to do with the size of the tumor, and the degree to which it has penetrated. When the tumor is small and has not penetrated the mucosal layer, it is said to be stage I cancer. Stage II tumors are into the muscle wall, and stage III involves nearby lymph nodes. The rare stage IV cancer has spread (metastasized) to remote organs.

The barium enema is a valuable diagnostic tool that helps detect abnormalities in the large intestine (colon). The barium enema, along with colonoscopy, remain standards in the diagnosis of colon cancer, ulcerative colitis, and other diseases of the colon.

tests for colon cancer

There are 4 basic tests for colon cancer: a stool test (to check for blood); sigmoidoscopy (inspection of the lower colon; colonoscopy (inspection of the entire colon); and double contrast barium enema. All 4 are effective in catching cancers in the early stages, when treatment is most beneficial.

How Fat Cells Work

A little more than half of the adults in the United States are overweight. Statistics show that an incredible 65.2 percent of the U.S. population is considered to be "overweight" or "obese." According to the Centers for Disease Control and Prevention (CDC), obesity and overweight status is determined in adults by finding a person's "Body Mass Index" or BMI.

BMI is a calculation that takes into consideration both a person's body weight and height to determine whether they are underweight, overweight or at a healthy weight. An adult who is considered "overweight" has a BMI somewhere between 25 and 29.9. An adult with a BMI of at least 30 is considered "obese." This measurement is used because it's typically a good indicator of body fat.

Whether due to concern for related health risks (high blood pressure, heart disease, diabetes, sleep apnea, respiratory problems, etc.), or just for sheer aesthetics, many Americans worry about fat. In fact, at this very moment, thousands of Americans are exercising or dieting to reduce their amount of body fat. But have you ever wondered what fat is? When a person "gets fat" -- gains weight -- what is actually happening inside the person's body? What are "fat cells" and how do they work?

Fat, or adipose tissue, is found in several places in your body. Generally, fat is found underneath your skin (subcutaneous fat). There's also some on top of each of your kidneys. In addition to fat tissue, some fat is stored in the liver, and an even smaller amount in muscle.

Where fat is concentrated in your body depends upon whet her you are a man or woman:

An adult man tends to carry body fat in his chest, abdomen and buttocks, producing an "apple" shape.

An adult woman tends to carry fat in her breasts, hips, waist and buttocks, creating a "pear" shape.

The difference in fat location comes from the sex hormones estrogen and testosterone. Fat cells are formed in the developing fetus during the third trimester of pregnancy, and later at the onset of puberty, when the sex hormones "kick in." It is during puberty that the differences in fat distribution between men and women begin to take form. One amazing fact is that fat cells generally do not generate after puberty -- as your body stores more fat, the number of fat cells remains the same. Each fat cell simply gets bigger! (There are two exceptions: the body might produce more fat cells if an adult gains a significant amount of weight or has liposuction performed.)

In this article, we will look at how fat cells store fat and how they get rid of it. See the next page to learn more.

Body Fat Basics

The human body contains two types of fat tissue:

White fat is important in energy metabolism, heat insulation and mechanical cushioning.

Brown fat is found mostly in newborn babies, between the shoulders, and is important for thermogenesis (making heat). Since adult humans have little to no brown fat, we'll concentrate on white fat in this article. See the bottom of this page for more on brown fat.

Fat tissue is made up of fat cells, which are a unique type of cell. You can think of a fat cell as a tiny plastic bag that holds a drop of fat. White fat cells are large cells that have very little cytoplasm, only 15 percent cell volume, a small nucleus and one large fat droplet that makes up 85 percent of cell volume.

How Fat Enters Your Body

When you eat food that contains fat, mostly triglycerides, it goes through your stomach and intestines. In the intestines, the following happens:

1.Large fat droplets get mixed with bile salts from the gall bladder in a process called emulsification. The mixture breaks up the large droplets into several smaller droplets called micelles, increasing the fat's surface area.

2.The pancreas secretes enzymes called lipases that attack the surface of each micelle and break the fats down into their parts, glycerol and fatty acids.

3.These parts get absorbed into the cells lining the intestine.

4.In the intestinal cell, the parts are reassembled into packages of fat molecules (triglycerides) with a protein coating called chylomicrons. The protein coating makes the fat dissolve more easily in water.

5.The chylomicrons are released into the lymphatic system -- they do not go directly into the bloodstream because they are too big to pass through the wall of the capillary.

6.The lymphatic system eventually merges with the veins, at which point the chylomicrons pass into the bloodstream.

You might be wondering why fat molecules get broken down into glycerol and fatty acids if they're just going to be rebuilt. This is because fat molecules are too big to easily cross cell membranes. So when passing from the intestine through the intestinal cells into the lymph, or when crossing any cell barrier, the fats must be broken down. But, when fats are being transported in the lymph or blood, it is better to have a few, large fat molecules than many smaller fatty acids, because the larger fats do not "attract" as many excess water molecules by osmosis as many smaller molecules would.

In the next section, we'll look at how fat is stored in your body.

Fat Storage

In the last section, we learned how fat in the body is broken down and rebuilt into chylomicrons, which enter the bloodstream by way of the lymphatic system.

Chylomicrons do not last long in the bloodstream -- only about eight minutes -- because enzymes called lipoprotein lipases break the fats into fatty acids. Lipoprotein lipases are found in the walls of blood vessels in fat tissue, muscle tissue and heart muscle.

Insulin

When you eat a candy bar or a meal, the presence of glucose, amino acids or fatty acids in the intestine stimulates the pancreas to secrete a hormone called insulin. Insulin acts on many cells in your body, especially those in the liver, muscle and fat tissue. Insulin tells the cells to do the following:

Absorb glucose, fatty acids and amino acids

Stop breaking down:

glucose, fatty acids and amino acids

glycogen into glucose

fats into fatty acids and glycerol

proteins into amino acids

Start building:

glycogen from glucose

fats (triglycerides) from glycerol and fatty acids

proteins from amino acids

The activity of lipoprotein lipases depends upon the levels of insulin in the body. If insulin is high, then the lipases are highly active; if insulin is low, the lipases are inactive.

The fatty acids are then absorbed from the blood into fat cells, muscle cells and liver cells. In these cells, under stimulation by insulin, fatty acids are made into fat molecules and stored as fat droplets.

It is also possible for fat cells to take up glucose and amino acids, which have been absorbed into the bloodstream after a meal, and convert those into fat molecules. The conversion of carbohydrates or protein into fat is 10 times less efficient than simply storing fat in a fat cell, but the body can do it. If you have 100 extra calories in fat (about 11 grams) floating in your bloodstream, fat cells can store it using only 2.5 calories of energy. On the other hand, if you have 100 extra calories in glucose (about 25 grams) floating in your bloodstream, it takes 23 calories of energy to convert the glucose into fat and then store it. Given a choice, a fat cell will grab the fat and store it rather than the carbohydrates because fat is so much easier to store.

Next, we'll look at how your body breaks down fat.

Breaking Down Fat

When you are not eating, your body is not absorbing food. If your body is not absorbing food, there is little insulin in the blood. However, your body is always using energy; and if you're not absorbing food, this energy must come from internal stores of complex carbohydrates, fats and proteins. Under these conditions, various organs in your body secrete hormones:

pancreas - glucagon

pituitary gland - growth hormone

pituitary gland - ACTH (adrenocorticotropic hormone)

adrenal gland - epinephrine (adrenaline)

thyroid gland - thyroid hormone

These hormones act on cells of the liver, muscle and fat tissue, and have the opposite effects of insulin.

When you are not eating, or you are exercising, your body must draw on its internal energy stores. Your body's prime source of energy is glucose. In fact, some cells in your body, such as brain cells, can get energy only from glucose.

The first line of defense in maintaining energy is to break down carbohydrates, or glycogen, into simple glucose molecules -- this process is called glycogenolysis. Next, your body breaks down fats into glycerol and fatty acids in the process of lipolysis. The fatty acids can then be broken down directly to get energy, or can be used to make glucose through a multi-step process called gluconeogenesis. In gluconeogenesis, amino acids can also be used to make glucose.

In the fat cell, other types of lipases work to break down fats into fatty acids and glycerol. These lipases are activated by various hormones, such as glucagon, epinephrine and growth hormone. The resulting glycerol and fatty acids are released into the blood, and travel to the liver through the bloodstream. Once in the liver, the glycerol and fatty acids can be either further broken down or used to make glucose.

Losing Weight and Losing Fat

Your weight is determined by the rate at which you store energy from the food that you eat, and the rate at which you use that energy. Remember that as your body breaks down fat, the number of fat cells remains the same; each fat cell simply gets smaller.

Most experts agree that the way to maintain a healthy weight is:

Eat a balanced diet - appropriate amounts of carbohydrates, fat and protein

Do not eat excessively - for most people, a diet of 1,500 to 2,000 calories a day is sufficient to maintain a healthy weight

Exercise regularly

For more information on fat and your health, check out the links on the following page.

Lots More Information

Related HowStuffWorks Articles

How Body Mass Index Works

How Fats Work

How Food Works

How Dieting Works

How Diet Pills Work

How the Atkins Diet Works

How Low-carb Dieting Works

How Calories Work

How to Plan a Weight Loss Diet

How Exercise Works

How Fat Vaccines Will Work

How Diabetes Works

How Heart Disease Works

How Liposuction Works

Is a lack of sleep making me fat?

More Great Links

American Obesity Association

CDC: Overweight and Obesity

MedlinePlus: Weight Control

How Cholesterol Works

What is Cholesterol?

Cholesterol is a waxy, fat-like compound that belongs to a class of molecules called steroids. It's found in many foods, in your bloodstream and in all your body's cells. If you had a handful of cholesterol, it might feel like a soft, melted candle. Cholesterol is essential for:

1.Formation and maintenance of cell membranes (helps the cell to resist changes in temperature and protects and insulates nerve fibers)
2.Formation of sex hormones (progesterone, testosterone, estradiol, cortisol)
3.Production of bile salts, which help to digest food
4.Conversion into vitamin D in the skin when exposed to sunlight.

The formation of cholesterol involves a series of complicated biochemical reactions that begin with the widespread 2-carbon molecule Acetyl CoA: Acetyl CoA (C2) --> mevalonate (C6) --> isopentenyl pyrophosphate (C5) --> squalene (C30) --> cholesterol (C27).

Cholesterol is made primarily in your liver (about 1,000 milligrams a day), but it is also created by cells lining the small intestine and by individual cells in the body.

Blood Cholesterol vs. Dietary Cholesterol

It may surprise you to know that our bodies make all the cholesterol we need. When your doctor takes a blood test to measure your cholesterol level, the doctor is actually measuring the amount of circulating cholesterol in your blood, or your blood cholesterol level. About 85 percent of your blood cholesterol level is endogenous, which means it is produced by your body. The other 15 percent or so comes from an external source -- your diet. Your dietary cholesterol originates from meat, poultry, fish, seafood and dairy products. It's possible for some people to eat foods high in cholesterol and still have low blood cholesterol levels. Likewise, it's possible to eat foods low in cholesterol and have a high blood cholesterol level.

So, why is there so much talk about cholesterol in our diet? It's because the level of cholesterol already present in your blood can be increased by high consumption of cholesterol and saturated fat in your diet. This increase in dietary cholesterol has been associated with atherosclerosis, the build-up of plaques that can narrow or block blood vessels. (Think about what happens to your kitchen drain pipes when you pour chicken fat down the sink.) If the coronary arteries of the heart become blocked, a heart attack can occur. The blocked artery can also develop rough edges. This can cause plaques to break off and travel, obstructing blood vessels elsewhere in the body. A blocked blood vessel in the brain can trigger a stroke.

The average American man eats about 360 milligrams of cholesterol a day; the average woman eats between 220 and 260 milligrams daily. So how are we doing? The American Heart Association recommends that we limit our average daily cholesterol intake to less than 300 milligrams. Obviously, people with high levels of cholesterol in the blood should take in even less.

Good and Bad Cholesterol

Comments about "good" and "bad" cholesterol refer to the type of carrier molecule that transports the cholesterol. These carrier molecules are made of protein and are called apoproteins載脂蛋白. They are necessary because cholesterol and other fats (lipids) can't dissolve in water, which also means they can't dissolve in blood. When these apoproteins are joined with cholesterol, they form a compound called lipoproteins. The density of these lipoproteins is determined by the amount of protein in the molecule. "Bad" cholesterol is the low-density lipoprotein (LDL), the major cholesterol carrier in the blood. High levels of these LDLs are associated with atherosclerosis. "Good" cholesterol is the high-density lipoprotein (HDL); a greater level of HDL--think of this as drain cleaner you pour in the sink--is thought to provide some protection against artery blockage.

A high level of LDL in the blood may mean that cell membranes in the liver have reduced the number of LDL receptors due to increased amounts of cholesterol inside the cell. After a cell has used the cholesterol for its chemical needs and doesn't need any more, it reduces its number of LDL receptors. This enables LDL levels to accumulate in the blood. When this happens, the LDLs begin to deposit cholesterol on artery walls, forming thick plaques. In contrast, the HDLs--the "good" guys--act to remove this excess cholesterol and transport it to the liver for disposal.

A third group of carrier molecules, the very low-density lipoproteins (VLDL) are converted to LDL after delivering triglycerides to the muscles and adipose (fat) tissue.

The levels of HDL, LDL and total cholesterol are all indicators for atherosclerosis and heart attack risk. People who have a cholesterol level of 275 or greater (200 or less is desirable) are at significant risk for a heart attack, despite a favorable HDL level. In addition, people who have normal cholesterol levels but low HDL levels are also at increased risk for a heart attack.

Cholesterol Risk Factors

There are a number of factors that influence a person's cholesterol levels. They include diet, age, weight, gender, genetics, diseases and lifestyle.

Diet

There are two dietary factors associated with increases in blood cholesterol levels:

Eating foods that are high in saturated fats, even if the fats themselves do not contain cholesterol. (These include foods containing high levels of hydrogenated vegetable oils, especially palm and coconut oils, avocados and other high-fat foods of vegetable origin.)

Eating foods containing high levels of cholesterol. (This group includes eggs and red meat--the most maligned of the cholesterol culprits--as well as lard and shrimp. These foods can significantly raise blood cholesterol levels, especially when combined with foods that are high in saturated fat.)

It's important to note that only foods of animal origin contain cholesterol. Lack of awareness of this fact has led to some confusing labels at the grocery store. For example, some items that are high in saturated fats from plant sources bear labels claiming that they are 100 percent cholesterol free. The statement may be true, but it's generally misleading because it implies that the product is definitely beneficial to your health.

Age

The blood levels of cholesterol tend to increase as we age--a factor doctors consider when deciding treatment options for patients with certain cholesterol levels.

Weight

People who are overweight are more likely to have high blood cholesterol levels. They also tend to have lower HDL levels. The location of the excess weight also seems to play a role in cholesterol levels. A greater risk of increased cholesterol levels occurs when that extra weight is centered in the abdominal region, as opposed to the legs or buttocks.

Gender

Men tend to have higher LDL levels and lower HDL levels than do women, especially before age 50. After age 50, when women are in their post-menopausal years, decreasing amounts of estrogen are thought to cause the LDL level to rise.

Genetics

Some people are genetically predisposed to having high levels of cholesterol. A variety of minor genetic defects can lead to excessive production of LDLs or a decreased capacity for their removal. This tendency towards high cholesterol levels is often passed on from parents to their children. If your parents have high cholesterol, you need to be tested to see if your cholesterol levels are also elevated.

Diseases

Diseases such as diabetes can lower HDL levels, increase triglycerides and accelerate the development of atherosclerosis. High blood pressure, or hypertension, can also hasten the development of atherosclerosis, and some medications used to treat it can increase LDL and triglycerides and decrease HDL levels.

Lifestyle

Factors that negatively affect cholesterol levels also include high levels of stress, which can raise total cholesterol levels, and cigarette smoking, which can lower a person's HDL level as much as 15 percent. On the other hand, strenuous exercise can increase HDL levels and decrease LDL levels. Exercise also can help reduce body weight, which, in turn, can help reduce cholesterol. Recent research has shown that moderate alcohol use (one drink per day for women, two drinks a day for men) can raise HDL cholesterol and therefore reduce the risk of heart attack. Despite such research, it is difficult to recommend the habitual use of alcohol, because there are also negative health consequences associated with alcohol use and a high potential for abuse.

Always remember that risk factors for high cholesterol and cardiovascular disease don't exist in a vacuum--they tend to amplify each other. Reducing the risk of a cardiovascular disease involves eliminating all of the risk factors that we can control and seeking medical advise for those we can't.

Cholesterol Testing and Prevention

How often should I have my cholesterol levels tested?

You should get your cholesterol tested every three to five years, more often if you have high cholesterol levels. Please refer to the table below for guidelines for total cholesterol, LDL and HDL levels.

What can I do to reduce my cholesterol?

There are several steps you can take to reduce your cholesterol levels. The first is to eat a low-fat, low-cholesterol diet. That means keeping your total fat consumption--saturated, polyunsaturated and monounsaturated--to fewer than 30 percent of your daily intake of calories. (See How Fat Works for details.) Remember to keep your cholesterol intake to fewer than 300 milligrams per day. Saturated fats contained in butter, whole milk, hydrogenated oils, chocolate shortening, etc. should comprise no more than one third of your total fat consumption. To reduce your total fat and cholesterol intake, limit your consumption of meats such as beef, pork, liver and tongue (always trim away excess fat). In addition, avoid cheese, fried foods, nuts and cream, and try to curb your intake of eggs to no more than four per week. Try to eat meatless meals several times a week, use skim milk and include fish in your diet. Eat a wide variety of vegetables, pasta, grains and fruit. Another good tip is to look at the package label of the foods you buy, and restrict your choices to foods containing 3 grams of fat or less per serving.

There is evidence that water-soluble fibers can aid in lowering cholesterol; these foods include the fiber in oat or corn bran, beans and legumes, pectin found in apples and other fruits, and guar that is used as a thickener. Although highly touted by the media and health food stores, the phospholipid Lecithin has not been confirmed as a reducer of blood cholesterol levels.

If you are overweight, trying to lose weight and including aerobic exercise in your routine can help raise those desirable HDL levels. Diet and exercise alone can decrease cholesterol levels by up to 15 percent.

It probably comes as no surprise to you that, if you smoke, you should quit to avoid a wide range of health problems, including lower HDL levels and increased risk of heart attack.

Medicating High Cholesterol

Sometimes positive changes in diet, lifestyle and exercise are not enough. In these cases, doctors may consider the use of medication that lowers cholesterol. The decision to have a patient begin medication is often based on high levels of LDL cholesterol and other risk factors for cardiovascular disease. For example, medication may be indicated if your LDL level is over 190 or is over 160 and you have several other risk factors for cardiovascular disease.

Drugs that reduce LDL blood levels can prevent or reduce the build-up of artery-blocking plaques and can limit the possibility of the release of those plaques as dangerous blood clots. There are several types of drugs that can help reduce blood cholesterol levels. The most commonly prescribed are the statins, HMG-CoA reductase inhibitors, including:

Lovastatin (Mevacor)

Simvastatin (Zocor)

Atorvastatin (Lipitor), a new, highly potent drug

These drugs work within the liver to directly prevent the formation of cholesterol and can lower LDL cholesterol by as much as 40 percent. Research also shows that these drugs can reduce the risk of death from cardiovascular disease. Another major drug category is the resins, which bind bile acids, causing the liver to produce more of them and using up cholesterol in the process. By "tying" it up, these drugs make cholesterol less available in the blood. They include:

Cholestyramine (Questran)

Colestipol (Colestid)

The B vitamin Niacin, in high doses, can lower triglycerides and LDL levels and increase HDL levels. Niacin has been proven to reduce a person's risk of having a second heart attack. Last are the drugs in the fibrates category, which lower triglycerides and can increase HDL levels. These include:

Gemfibrozil (Lopid)

Fenofibrate (Tricor)

The decision to take cholesterol- or lipid-lowering drugs is not taken lightly by your doctor. These drugs can be fairly expensive and are often required for many years or even the rest of your life. It is also important to note that some of these drugs can have dangerous side effects, such as damage to the liver.

Adopting a healthy lifestyle and visiting your doctor regularly can help curb your risks of problem cholesterol. Have your cholesterol levels checked by a physician, rather than risk incorrectly interpreting numbers in self test kits currently on the market. Remember, cholesterol is necessary for life but it can also be very harmful and requires monitoring. So, watch your cholesterol and keep in mind that, for every 1 percent drop in your cholesterol level, your risk of heart attack is lowered by 2 percent.

For more information on cholesterol and related topics, check out the links on the next page.

Cholesterol: Lots More Information

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What is open heart surgery and a bypass operation?

How do human blood types work?

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Blood Quiz

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How Calories Work

Inside this Article
1. Introduction to How Calories Work
2. What is a Calorie?
3. What Calories Do
4. BMR
5. Your Caloric Needs
6. Calories, Fat and Exercise
7. Lots More Information
8. See all Weight Loss articles

For years now, calories have been all the rage -- people are counting them and cutti­ng them, and you'd be hard-pressed to find something at the supermarket that does not list its calories per serving somewhere on the package. But have you ever wondered what exactly a calorie is?
In this article, we'll find out what calories are and why we need them, and examine the relationship between calories and weight.

What is a Calorie?
A calorie is a unit of energy. We tend to associate calories with food, but they apply to anything containing energy. For example, a gallon (about 4 liters) of gasoline contains about 31,000,000 calories.
Specifically, a calorie is the amount of energy, or heat, it takes to raise the temperature of 1 gram of water 1 degree Celsius (1.8 degrees Fahrenheit). One calorie is equal to 4.184 joules, a common unit of energy used in the physical sciences.
Most of us think of calories in relation to food, as in "This can of soda has 200 calories." It turns out that the calories on a food package are actually kilocalories (1,000 calories = 1 kilocalorie). The word is sometimes capitalized to show the difference, but usually not. A food calorie contains 4,184 joules. A can of soda containing 200 food calories contains 200,000 regular calories, or 200 kilocalories. A gallon of gasoline contains 31,000 kilocalories.
The same applies to exercise -- when a fitness chart says you burn about 100 calories for every mile you jog, it means 100 kilocalories. For the duration of this article, when we say "calorie," we mean "kilocalorie."

Caloric Breakdown
· 1 g Carbohydrates: 4 calories
· 1 g Protein: 4 calories
· 1 g Fat: 9 calories

What Calories Do
Human beings need energy to survive -- to breathe, move, pump blood -- and they acquire this energy from food.
The number of calories in a food is a measure of how much potential energy that food possesses. A gram of carbohydrates has 4 calories, a gram of protein has 4 calories, and a gram of fat has 9 calories. Foods are a compilation of these three building blocks. So if you know how many carbohydrates, fats and proteins are in any given food, you know how many calories, or how much energy, that food contains.
If we look at the nutritional label on the back of a packet of maple-and-brown-sugar oatmeal, we find that it has 160 calories. This means that if we were to pour this oatmeal into a dish, set the oatmeal on fire and get it to burn completely (which is actually pretty tricky), the reaction would produce 160 kilocalories (remember: food calories are kilocalories) -- enough energy to raise the temperature of 160 kilograms of water 1 degree Celsius. If we look closer at the nutritional label, we see that our oatmeal has 2 grams of fat, 4 grams of protein and 32 grams of carbohydrates, producing a total of 162 calories (apparently, food manufacturers like to round down). Of these 162 calories, 18 come from fat (9 cal x 2 g), 16 come from protein (4 cal x 4 g) and 128 come from carbohydrates (4 cal x 32 g).
Our bodies "burn" the calories in the oatmeal through metabolic processes, by which enzymes break the carbohydrates into glucose and other sugars, the fats into glycerol and fatty acids and the proteins into amino acids (see How Food Works for details). These molecules are then transported through the bloodstream to the cells, where they are either absorbed for immediate use or sent on to the final stage of metabolism in which they are reacted with oxygen to release their stored energy.
Click here for a simplified diagram of these metabolic processes.

BMR
Just how many calories do our cells need to function well? The number is different for every person. You may notice on the nutritional labels of the foods you buy that the "percent daily values" are based on a 2,000 calorie diet -- 2,000 calories is a rough average of what a person needs to eat in a day, but your body might need more or less than 2,000 calories. Height, weight, gender, age and activity level all affect your caloric needs. There are three main factors involved in calculating how many calories your body needs per day:
· Basal metabolic rate
· Physical activity
· Thermic effect of food
Your basal metabolic rate (BMR) is the amount of energy your body needs to function at rest. This accounts for about 60 to 70 percent of calories burned in a day and includes the energy required to keep the heart beating, the lungs breathing, the kidneys functioning and the body temperature stabilized. In general, men have a higher BMR than women. One of the most accurate methods of estimating your basal metabolic rate is the Harris-Benedict formula:
· Adult male: 66 + (6.3 x body weight in lbs.) + (12.9 x height in inches) - (6.8 x age in years)
· Adult female: 655 + (4.3 x weight in lbs.) + (4.7 x height in inches) - (4.7 x age in years)
(Note: The first number in the equation for females is, in fact, 655. Strange but true.)

Your Caloric Needs
As you now know, there are three main factors involved in calculating how many calories your body needs per day: your BMR, physical activity and the thermic effect of food.
The second factor in the equation, physical activity, consumes the next highest number of calories. Physical activity includes everything from making your bed to jogging. Walking, lifting, bending, and just generally moving around burns calories, but the number of calories you burn in any given activity depends on your body weight. Click here for a great table listing the calories expended in various physical activities and for various weights.
The thermic effect of food is the final addition to the number of calories your body burns. This is the amount of energy your body uses to digest the food you eat -- it takes energy to break food down to its basic elements in order to be used by the body. To calculate the number of calories you expend in this process, multiply the total number of calories you eat in a day by 0.10, or 10 percent. If you need some help determining how many calories you eat in a day, check out these sites:
· USDA National Nutrient Database
· Food Data
· Mike's Calorie And Fat Gram Chart
The total number of calories a body needs in a day is the sum of these three calculations. If you only want a rough estimate of your daily caloric needs, you can skip the calculations and click here.

Calories, Fat and Exercise
So what happens if you take in more or fewer calories than your body burns? You either gain or lose fat, respectively. An accumulation of 3,500 extra calories is stored by your body as 1 pound of fat -- fat is the body's way of saving energy for a rainy day. If, on the other hand, you burn 3,500 more calories than you eat, whether by exercising more or eating less, your body converts 1 pound of its stored fat into energy to make up for the deficit.
One thing about exercise is that it raises your metabolic rate not only while you're huffing and puffing on the treadmill. Your metabolism takes a while to return to its normal pace. It continues to function at a higher level; your body burns an increased number of calories for about two hours after you've stopped exercising.
Lots of people wonder if it matters where their calories come from. At its most basic, if we eat exactly the number of calories that we burn and if we're only talking about weight, the answer is no -- a calorie is a calorie. A protein calorie is no different from a fat calorie -- they are simply units of energy. As long as you burn what you eat, you will maintain your weight; and as long as you burn more than you eat, you'll lose weight.
But if we're talking nutrition, it definitely matters where those calories originate. Carbohydrates and proteins are healthier sources of calories than fats. Although our bodies do need a certain amount of fat to function properly -- an adequate supply of fat allows your body to absorb the vitamins you ingest -- an excess of fat can have serious health consequences. The U.S. Food and Drug Administration recommends that a maximum of 30 percent of our daily calories come from fat. So, if you eat 2,000 calories a day, that's a maximum of 600 calories from fat, or 67 grams of fat, per day. However, many doctors and nutritionists now set the maximum number of fat calories at 25 percent of our daily caloric intake. That's 56 grams of fat per day for a 2,000 calorie diet.
Here are some calorie and fat contents that may surprise you:
For more information on calories, dieting, nutrition and related topics, check out the links on the next page!

Related HowStuffWorks Articles
· How Food Works
· How Fats Work
· How Fat Cells Work
· How Cholesterol Works
· How Exercise Works
· How Dieting Works
· How Diet Pills Work
· Does drinking ice water burn calories?
· How many calories does a person need daily?
· How can a diet pill make you feel full?
· Would a fat tax save lives?
· How Vegetarians Work
· How Vegans Work
More Great Links
· Nutrition Calculators
· CaloriesPerHour.com
· Food For Thought: An Interview with Nutrition Scientist Dr. Paul Saltman
· What a Set of Batteries!: A Commentary on the Origin and Use of Our Body's Energy
· Experiment: Measuring the Number of Calories in Sunlight - PDF

The human body is an amazing machine, and every once in a while it will do something to remind you that it's working hard to keep you alive and well. The stomach growl is one of these reminders. Loud, soft and sometimes for no good reason at all, your growling stomach has a lot to say.
Whether you call it grumbling, rumbling, gurgling or growling, from time to time everybody's belly chimes in. These noises might sound like they should be coming from a noisy pot of bubbling stew rather than your stomach.
­But the big question is, why does it growl in the first place? And why does your stomach seem to growl the moment a room grows quiet?

­Your stomach doesn't have such perfect timing or such a malicious sense of sabotage. But there is a perfectly logical explanation why your stomach sometimes feels the need to be heard.
Let's examine this age-old question on the next page and discover why Winnie the Pooh isn't the only one with a rumbly in his tumbly.

Causes of Stomach Growling
Stomach growling, which originates in the stomach and the small intestine, can be explained by a closer look at how the digestive system functions.

The digestive system is, in essence, a long tube that starts at the mouth and ends at the anus. This tube connects with the various organs and passages that play important roles in digestion. One of the most important things to know about the digestive system is the manner in which it propels food. Waves of muscle contractions move and push the contents continually downward in a process called peristalsis蠕動. In addition to moving your meal along its digestive path, these contractions also help churn food, liquid and different digestive juices together, rendering them into a gooey mix known as chyme.
Stomach growling is the result of this process. Moving with those solid and liquid chyme ingredients are gasses and air. As all these ingredients get pushed around and broken down into easy-to-absorb bits, pockets of air and gas also get squeezed and create the noises we hear. Stomach growling can happen at any time -- not just when you're hungry -- but if there's food in your stomach or small intestine, the growling becomes quieter. It's like putting a pair of sneakers in the dryer by themselves versus with a load of towels. The towels muffle the noise of the shoes as they bounce around.
But you may be wondering -- if your stomach is empty, why are the muscle contractions that digest food happening to begin with? The reason has to do with hunger and appetite. About two hours after your stomach empties itself, it begins to produce hormones that stimulate local nerves to send a message to the brain. The brain replies by signaling for the digestive muscles to restart the process of peristalsis. Two results occur: First, the contractions sweep up any remaining food that was missed the first time around. Second, the vibrations of an empty stomach make you hungry. Muscle contractions will come and go about every hour, generally lasting 10 to 20 minutes, until you eat again. Learn more about the twists and turns your food takes after your first bite by reading How the Digestive System Works.

Word Origins
The technical name for the noises made by a grumbling stomach is borborygmi (borborygmus 腹鳴is the singular form). The term comes from the Greek word borborugmos, an example of onomatopoeia擬聲調 (a word created to imitate a sound). Borborygmi illustrates what stomach growling might sound like in word form. Onomatopoeia is commonly used for animal sounds and other noises, and can differ between languages. Examples in the English language include bang, hiss, whisper and buzz.


In some cases, excessive gurgling and grumbling may be a sign of an upset stomach or a medical condition like irritable bowel syndrome. In these cases, there are usually a number of additional gastrointestinal complaints accompanying a growling stomach.
So now that we know what causes stomach growling, is there any way to control it? One tip to mute a noisy belly is to eat many small meals instead of a few large ones. Your digestive system will have less opportunity to create those peristalsis rumbles if your body has something tasty in it. Also, eating less gaseous foods may help decrease the growling.
So, is your body making any other weird noises? Visit the links on the next page to learn more about the human body.

Lots More Information
Related HowStuffWorks Articles
How Calories Work
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How Cholesterol Works
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How does your stomach keep from digesting itself?
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How Fat Cells Work
How Fats Work
How Food Works
How The Digestive System Works
How Vegans Work
How Vegetarians Work
Irritable Bowel Syndrome
More Great Links
Digestive Disorders Health Center
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pchomehttp://www.pchome.com.tw

元素表

How Heart Disease Works

by Carl Bianco, MD

Please copy/paste the following text to properly cite this HowStuffWorks article:
Bianco, Carl. "How Heart Disease Works." 01 April 2000. HowStuffWorks.com. 30 June 2009.
Inside this Article
Introduction to How Heart Disease Works
Atherosclerosis: Are You at Risk?
Angina
Heart Attack
Lots More Information
See all Cardiovascular Conditions articles
Heart Effects


More Health Videos »
Heart Health Image GallerySee more heart health pictures.
Heart disease is the leading cause of death in the U.S. At some point in your life, either you or one of your loved ones will be forced to make decisions about some aspect of heart disease. Knowing something about the anatomy and functioning of the heart, in particular how angina and heart attacks work, will enable you to make informed decisions about your health.
Heart disease can strike suddenly and require you to make decisions quickly. Being informed prior to an emergency is a valuable asset to you and your family.
In this article we will discuss various heart diseases and how they can lead to a heart attack, or even a stroke. We will also look at how heart attacks are treated and what you should do to prevent heart disease.
Additional ReadingThis article is preceeded by two others that will be extremely helpful to you in understanding heart disease:
How the Heart Works
How Diagnosing Heart Disease Works Reading these two articles prior to reading this one will give you the background you need on the anatomy and functioning of the heart.
The basics Coronary Artery Disease (CAD), Coronary Heart Disease (CHD), Ischemic Heart Disease (IHD) and Arteriosclerotic Cardiovascular Disease (ASCVD) are all different names for the same disease. This disease is caused by atherosclerosis, which is a buildup of fatty deposits (atheroma) in the coronary arteries. See the figure below:
Photo courtesy -->CAPTION -->
Coronary arteries supply blood to the heart muscle. When a blockage occurs in one of these arteries, blood flow to the heart muscle is decreased. This becomes most evident during exertion. During exertion, the heart muscle is working harder and needs more oxygen-enriched blood than usual. By preventing the much needed increase in blood flow, the blockage deprives the heart muscle of oxygen thereby causing the heart muscle to hurt. This chest pain is called angina or Angina Pectoris. When the heart muscle goes without sufficient oxygen, the muscle is said to be ischemic. If cell death occurs it is called infarction. Since a heart attack is cell death of heart muscle (myocardium), it is called a Myocardial Infarction (MI). The condition that causes CAD, angina and heart attacks is called atherosclerosis.
Arteriosclerosis is a more general term for hardening of the arteries. Atherosclerosis is a type of arteriosclerosis that causes a buildup of fatty material (referred to as atheromas and plaques) along the inner lining of arteries. Depending on where these blockages occur, they can cause a number of different outcomes:
If the blockage occurs in a coronary artery, it causes chest pain (angina).
If the blockage is complete, it can cause a heart attack (Myocardial Infarction or MI).
If the blockage occurs in one of the arteries near the brain, a stroke can occur.
If a blockage occurs in a leg artery, it causes Peripheral Vascular Disease (PVD) and can cause pain while walking called intermittent claudication.
­Atherosclerosis takes many years, even decades to develop and the condition can easily go unnoticed. Sometimes symptoms such as angina will gradually indicate the condition. However, it can also become evident in a sudden and severe way, in the form of a heart attack.
Let's take a look at some of the risk factors for atherosclerosis. Some of these factors are things you can control. By being proactive, you could reduce your risk.

滿水之杯，裝不進「水和智慧」！

學習活得好，勝過功課好！
文/戴晨志　2009.01.08
快樂，是可以選擇的！當我們跟不同的人相處，我們試著看他的長處，也秉著「肯定自己、接納對方」的心情，我們就會更加快樂！
千萬不能「埋怨他人、封閉自己」啊！
最近有一位大學女生告訴我說，她的英文被老師「當掉」了。
問她為什麼？她說，因為那個英文男老師很色，第一次來上課就一直聊天，又開黃腔、講黃色笑話，真是很無聊，一看到他就很討厭；所以她很不喜歡這男老師的課，最後，就被老師當掉了！
唉，這是多麼可惜呀！英文被當掉，明年還要重修一次，多划不來呀！
記得我在美國念碩士時，我知道我的功課不夠好，也沒有辦法和其他美國同學一樣地搶答、辯論或是談笑風生；而且，有一男教授很嚴格、很有權威，打起分數，更是不留情面。怎麼辦呢？我不能讓教授覺得我程度不好，而把我「當掉」呀！我必須「主動打開僵局」！
於是，我決定「主動親近教授」。在教授的「office hour」，也就是「在辦公室指導學生的時間」，我一定準備問題去請教這名教授，讓他知道，我是十分努力、用功的外籍學生，只是英文表達能力不夠好而已。
而且，在教授上課前，我常陪著教授從辦公室，踏著白雪，走到教室，一路請教他；而在下課後，當全班同學已經鳥獸散時，我又陪著教授，踏著白雪，走回辦公室。您想想看這幅畫面－－「縮著身子，陪著老師、踏著白雪一起走路、一路請教老師」，那是多麼難得的「師生之情」啊！
或許有人會覺得我「很狗腿」、「很噁心」或「很虛偽」，可是，這些舉動，會讓老師看見學生的「虛心求教」和「尊師重道」呀；即使是在寒冷的冬天，老師的心和我的心，也都會覺得無比溫暖呀！
後來，那最嚴格的一科，我得了「Ｂ」，過關了。可是我們班上另外兩名老中，他們的命運就不一樣了，他們都拿了「Ｆ」，被教授當掉了！我問他們：「我不是已經從助教那兒硬拗來一些考古題，事前拿給你們看了嗎？」
我印象很深刻，那兩名老中回答我說－－他們也曾去請教教授，可是那教授的態度很「歧視台灣學生」，在對他們講話時，教授的雙腳竟「蹺在桌上」，還「咬著蘋果」，一副很不屑的樣子。
我不清楚那教授是不是會「歧視台灣學生」？根據我的經驗是「不會」！或許，只是他們自己的感覺吧！可是，即使老師有一點歧視，我們為什麼要「擴大老師的缺點、縮小他的優點」呢？我們可以「主動接近老師、多欣賞他的優點」，讓師生的關係逐漸改善啊！
有句話說：「當我們看不順眼的人愈來愈多時，看我們順眼的人，就會愈來愈少！」的確，假如我們看不順眼老師、看不順眼老闆，相對地，老師或老闆也會看我們不順眼呀！
因 此，「角色扮演」很重要。一個學生或部屬，都沒有資格瞧不起老師和上司，畢竟他們的經驗都比我們豐富，也都坐上了那個位子；他們即使沒有真才實學，但多少都有值得我們學習之處啊！我們絕不能「恃才傲物、憤世嫉俗、孤芳自賞」，否則，就會像許多天才的命運一樣，斷送在「自認為自己很天才」之上呀！
我認識一女孩，國立大學物理系碩士第一名畢業，連男生都不是她的對手。後來，她獲得「全額獎學金」到紐約攻讀博士，系上的老師們相信，她一定可以在三年內（二十八歲前），拿到博士學位。
在紐約念書時，這女孩的成績幾乎都拿到「Ａ」。可是，當她在做實驗研究時，與教授起了衝突。她堅持，是教授的見解有錯，結果，兩人水火不容；最後，博士資格考時，被教授當掉、退學了。
後來這女孩回台一陣，又申請到加州的一所名校，繼續攻讀博士；可是她在寫論文時，又批評教授的看法有誤，也嫌教授雜務太多、不專心做研究、懂得沒有比她多，實在「不夠格」來指導她。最後，這女孩又黯然離開了那加州大學。
您 知道嗎，這天才型的女孩、物理頂尖高手，在美國念了「四所大學博士班」，到了現在四十歲了，都沒有拿到學位。她總是在越洋電話中告訴家人－－我的指導教授「很爛」、「沒什麼程度」、「沒資格指導論文」……如今，這女孩，噢，不，應說是「女士」，孤獨地回到台灣，天天窩在家裡，看書、看電視、睡覺，也不出去找工作，讓年邁的老爸頭痛不已。
事實上，我們的人生不能是一個「滿水的杯」，別人隨便一拍，水就滿溢出來；我們每天必須是個「倒空的杯」，虛心學習，讓更多的「水」和「智慧」，都能放進我們生命的「空杯」之中啊！
【本文摘錄自《戴晨志幽默加油站》推薦《少抱怨多實踐》時報文化】

腦幹的功能性解剖

中樞神經系統(腦和脊髓)
周邊神經系統(12對的顱神經和31對脊神經)
神經組織(主要由神經元及神經膠細胞構成；神經元可傳導神經衝動，神經膠細胞可以支持、保護和滋養神經元)。

蔡明達　洪祖培
ž神經系統
簡介
神經系統可分成中樞神經系統和周邊神經系統，兩個系統共同合作彼此連結，完成神經系統的功能。前者包括腦和脊髓，後者包含12對的顱神經和31對脊神經。神經組織主要由神經元及神經膠細胞構成；神經元可傳導神經衝動，神經膠細胞可以支持、保護和滋養神經元。存在於皮膚和器官中的末梢神經受器，接受對外在和內在的刺激產生神經衝動，向上傳導到中樞神經系統，在此整合，經過組織化的認知，做出意識層次的決定以及下意識層次的反射反應，接著將此反應經由傳出神經構造將訊息送達肌肉和腺體，做出適當的反應，達到內在平衡(internal homeostasis)，維繫個體的健康與生存。
腦和脊髓分別在顱腔和脊椎管中而受保護，腦脊髓膜由硬腦膜、蜘蛛網膜和軟腦膜構成。硬腦膜緊貼顱骨和脊椎，蜘蛛網膜下腔為腦脊髓液循環經過之空腔，而軟腦膜則緊貼在大腦及脊髓之表面。腦部又可細分為大腦、間腦、腦幹及小腦。出枕骨大孔則是脊髓，連接周圍神經。
大腦
大腦的外層含細胞體和短神經纖維稱為皮質，皮質會有向內的彎區形成腦回，大腦被一個直的縱裂分成左右大腦半球，縱裂的基部是胼胝體，此為聯絡左右大腦的纖維束所形成；功能上，左側大腦含運動語言中樞，負責說話的能力，右側大腦在立體空間關係上優於左腦。每一個大腦半球皆有四葉：額葉、頂葉、顳葉和枕葉。功能上，額葉含控制隨意骨骼肌運動的初級運動區，並有額前聯結區執行較高智能的意識活動，如集中注意力、計劃並解決複雜的問題，判斷行為可能造成的後果等高階皮質功能；頂葉有認知體感初級感覺區，並有感覺聯結區，能夠了解語言和使用文字以表達思想，也能負責立體空間建構與思維；顳葉有初級聽覺區，並有聽覺聯結區能解釋聽覺經驗，並和其他體感視覺印象，音樂鑑賞等有綜合聯絡的能力；枕葉有初級視覺中樞，並有視覺聯結區可以統合視覺和其他感覺經驗，做出解釋及反應(圖一)。
基底核、邊緣系統及小腦
皮質下有基底核群，協調身體各部的運動，學習新的運動模式。另外有邊緣系統連結額葉、顳葉及間腦的部分構造，司營記憶、喜怒哀樂等情緒反應、性衝動，這些功能皆與個體的生存和種族的繁衍有關。間腦位於第三腦室彎，包括下視丘和視丘。下視丘主控維持內在環境的恆定，含有調節飢餓、睡眠、口渴、體溫、水分平衡和血壓的中樞，並與腦下腺功能有關；視丘為體感傳入神經抵達大腦中樞前的轉運站，並與基底核一般含有調節運動模式的功能。小腦位於大腦後部下方，前面以第四腦室與腦幹分隔，主要功能是維持肌肉正常張力、並協調肌肉動作，使得運動平滑順暢。
腦幹
腦幹就位於銜接在大腦、間腦與脊髓中間。周圍神經所有上行的訊息都經腦幹向上傳導；中樞的所有指令也經腦幹向下經脊髓到周圍神經所分佈的肌肉與腺體執行，如此佔有非常重要的樞紐地位。由上而下，腦幹分成中腦、橋腦和延髓：中腦包圍大腦導水管，除了做為大腦－脊髓及大腦－小腦間神經徑的延遲站之外，還有視覺、聽覺和觸覺的反射中樞；橋腦為大腦－小腦徑的延遲站並和延髓共同調節呼吸速率；延髓則含有一些調節心跳、呼吸和血壓的生命中樞，以及嘔吐、咳嗽、吞嚥的反射中樞。
腦部與意識有關的構造可分為兩部分，第一是大腦半球，與意識清醒時反應出來的內涵，負責認識、分辨周圍環境之能力有關。第二部分是腦幹上半段的上昇性網狀賦活系統(ascending reticular activating system, ARAS)，專司一個人的清醒與睡眠，如果這個系統有障礙，人就不能被喚醒。在正常的意識狀況，必須兩部分均有正常功能，如果腦幹的上昇性賦活系統破壞而失去功能，則不論大腦半球是否健全這個人將長久呈現昏睡狀況，如果大腦半球功能仍在，病人則呈現植物人狀況，但如果大腦功能也嚴重缺失，則病人死亡的機會十分高(圖二)。
ž腦幹的結構
解剖上，腦幹長約8cm，下接脊髓，上連間腦，背面有小腦覆蓋，由上而下可分為中腦(midbrain)、橋腦(pons)及延髓(medulla oblongata)三部分；將腦幹整體依水平切面觀察又可分為前中後三部分解剖構造，分別是基部(basis)、蓋膜(tegmentum)及頂蓋(tuctum)。
1. 基部：腦幹的基部包含由大腦皮質下行的運動徑，及分散在其中的橋腦神經核。運動徑包含二部分：(1)椎狀徑(pyramidal tracts)，包括皮質延髓徑(corticobulbar tracts)和皮質脊徑(corticospinal tracts)；(2)大腦橋腦徑(corticopontine tracts)，這是由大腦皮質經橋腦到小腦的運動神經路徑。若進一步詳細說明，中腦的基部包括了上述三個神經束，並無神經核；橋腦基部體積最大，主要是因它含有基部唯一的橋腦神經核，這些神經核接收了大腦橋腦徑的纖維，而傳出到小腦，皮質脊徑及皮質延髓徑，都經橋腦到達了延髓的基部。延髓的基部體積最小，這是由於大部分的皮質延髓徑神經已經進入中腦、橋腦部分，而皮質脊徑在延髓的部分外形成椎狀體，叫做延髓椎(medullary pyramidas)，因此這些傳導的運動路徑總稱為椎狀徑(pyramidal tracts)。
2. 蓋膜：內含灰質與白質兩部分。灰質的主要組成有：(1)第3對到第12對腦神經(第11對除外)的運動及感覺神經核；(2)網狀構造(reticular formation)神經核及(3)補充性(supplementary)運動及感覺神經核。包括延髓的下橄欖核(inferior olivary nuclei)、橋腦的基底核、中腦的紅核(red nuclei)及黑質體(substantia nigra)。
蓋膜的白質則包含(1)所有由脊髓或腦神經核傳導到小腦、腦幹及視丘的上升性感覺徑，(2)內側縱束(medial longitudinal fasciculus)，(3)小腦傳入及傳出路徑，(4)連接蓋膜、間腦及前腦灰質的蓋膜中央束(central tegmental tract)，以及(5)位於網狀構造中大量的未命名神經路徑。
3. 頂蓋：腦幹的頂蓋是指第四腦室後面的部分，由上而下分別是中腦的四疊板(quadrigeminal plate)、橋腦的前髓帆及延髓的後髓帆(anterior and posterior medullary vela)；頂蓋部分不含腦神經核，無網狀構造，也沒有直接上行及下行的感覺及運動路徑。
ž與腦死判定相關的腦幹解剖生理
三叉神經
三叉神經的運動核位於橋腦蓋膜的上端，負責咀嚼肌(嚼肌、顳肌、翼肌)及張鼓膜肌(tensor tympani)的活動。感覺核則包括：(1)傳導本體感覺(propriception)的中腦核，位於中腦。(2)傳導觸覺的感覺主核(main sensory nucleus)，位於橋腦及(3)傳導疼痛和溫度的三叉神經脊椎核，向下傳導到延髓和頸椎上半段的地方，位於延髓。離開腦幹後，三叉神經分為三個主要的分枝：視分枝、上頷分枝及下頷分枝。顏面的感覺訊息神經經由三叉神經核向上傳導，大部分主核及脊髓核的傳出神經交叉到對側的三叉神經蹄係，而部分主核及中腦核纖維未交叉走在同側三叉神經蹄係；再向上傳導到視丘及大腦皮質；有些傳出纖維經由網狀構造傳到相對應的顱神經運動核，形成反射弧包括下頷反射(三叉神經－三叉神經)、角膜反射(三叉神經－顏面神經反射)、噴嚏反射(三叉神經－網狀構造--皮質延髓徑及皮質脊徑反射)。
第八對顱神經的平衡部分
有關人體平衡訊息接受，需要靠二種接受器：顳骨內的三半規管含有壺腹脊(cristae of the ampullae)偵測旋轉及角度的加速、減速，而橢圓囊(utricle)及球囊(saccule)則用來偵測用力向下拉所引起的直線加速變化。這些平衡訊息傳導到內耳道的平衡神經節，這裡的雙極神經元為第一個神經元，將訊息向中樞神經傳導。
在內耳通道內平衡神經部分與聽神經與顏面神經走在一起，經由橋腦、延髓的交界處進入腦幹部。進入腦幹部之後，平衡神經纖維走向前到達前庭神經核(vestibular nuclei)，聽神經纖維則走向後到達聽神經核。其中平衡神經訊息則傳達到前庭神經核，小腦及網狀構造。在腦幹內的四個前庭神經核則是平衡傳導路徑的第二個神經元，它們接受的傳入訊息包括：第八對前庭神經的平衡訊息，脊椎前庭衡束(spinovestibular tract)，小腦前庭束(cebellovestibular tract)及網狀前庭束(reticulovestibular tract)。
而它的傳出神經元則到達下列地方以進行不同功能：
(1) 內側縱束(medial longitudinal fasciculus)，由此將訊息傳達到第3,4,6對負責眼睛活動的神經，由此再由傳達訊息的神經元傳達到脊椎，因此，這條路徑可以調節眼睛運動及頭部姿勢，以成協調作用。
(2) 前庭脊束(vestibulospinal tracts)直接傳導到脊椎的運動神經，這條神經束可以強化伸展肌肉的收縮，用以支持身體對抗重力的牽引。
(3) 前庭小腦路徑，此路徑被認為與身體縱軸肌肉維持上身垂直有關，是平衡網狀路徑，這種路徑一般認為與平衡神經異常所造成的噁心、嘔吐、臉色慘白、低血壓等反射作用有關，例如暈車。
(4) 前庭視丘皮質路徑，可以傳導平衡訊息到大腦皮質；此條路徑與平衡系統出現問題時，個體會注意到噁心、暈眩有關。
腦幹反射
所謂反射反應，是指當有足量的外在刺激傳入神經系統時，在不經過意識決定與控制的情況，經由反射中樞做出反應，將訊息傳到傳出神經系統以及肌肉組織做出迅速的反應。在腦幹這個複雜構造中，主導著很多重要的反射活動，通常這些反射動作無法正常運作時，也代表腦幹部的功能出現了嚴重的異常狀態。
1. 瞳孔對光反射(pupillary light reflex)：此反射是腦幹上段中腦的功能：瞳孔對光反射的檢查中，用強光照射一側的瞳孔，光線刺激過後會發現兩側瞳孔有對稱性收縮的現象叫做瞳孔光反射。傳入神經是由光線刺激到眼球視網膜的光線接收細胞，在顳側的訊息會經由視交叉的外側傳到同一側的頂蓋前核(pretectal nucleus)，如果是在皮側的另一訊息則會在視交叉傳導到對側的頂蓋前核，訊息再由頂蓋前核傳導到中腦的艾定魏佛核(Edinger-Westphal nucleus)，這是動眼神經束核區的一員，傳出神經是屬於副交感神經系統，其中的節前神經(pregiaglionice miber)的源頭就是艾定魏佛核，由此經由動眼神經傳入到一方內的脻狀神經節(ciliary ganglion)，節後神經再由此傳導到瞳孔外圍的環狀肌，環狀肌受到刺激收縮後瞳孔就會縮小。
2. 眼角膜反射(cornea reflex)：此反射是腦幹中段橋腦的功能。眼角膜的傳入訊息來自三叉神經的一般體表傳入訊息(general somatic afferent GSA)，當觸覺或壓覺刺激到眼角膜的上半段時，傳入神經訊息經由三叉神經的視分枝(第一分枝)經過三叉神經節傳入到腦幹。腦幹中接受此訊息是三叉神經的組合，如果訊息來自眼角膜的下半段，則是由三叉神經的顎枝(第二分枝)傳入，傳出神經元則是由腦幹部的反射中樞傳遞到位於橋腦的顏面神經核，再由顏面神經核經由顏面神經傳出到眼框輪肌，做成眼皮閉闔的反射動作。
3. 前庭--動眼反射：此反射是由橋腦下端與位於橋腦和中腦之內側縱束(medial longitudinal fasciculus)所構成。當一側耳朶之內淋巴受到冷溫度之刺激時，刺激經由第八條顱神經傳至橋腦，再由內側縱束引起同側眼之外直肌與對側眼之內直肌收縮，而使兩眼同時偏向同側而構成反射。
4. 作嘔反射(gag reflex)：此反射是腦幹下段延髓的功能。作嘔反射的傳入訊息可由壓舌板刺激咽喉後半段的喉壁，扁桃體區域或舌根區域。由此會引起一般內臟傳入神經訊息(general visceral afferent)，訊息經由舌咽神經傳到腦幹的橋腦及延髓的下神經結(inserior ganlion)。引起嘔吐的反射中樞就位於此區腦幹部。傳入神經訊息由嘔吐神經中樞傳出到經由舌下神經、迷走神經及舌咽神經等引起明顯的嘔吐反應，臨床上可觀察到軟顎上抬、舌頭向後縮及喉部肌肉的強烈收縮，會在受試者身上引起嘔吐的反射。
5. 頭--眼反射：此反射有較長之聯絡徑路，必須有相當健全之腦幹功能才能表現出來。當病人的頭由正前位置突然被轉至一側時，此轉動之動作刺激前庭系統之耳石或頸部之自體感覺(proprioceptive)或二者都參與反射，經由內側縱束之作用使兩眼仍處於正前方之位置，在轉動瞬間不隨著頭部之偏向而一起偏向。
網狀構造(reticular formation)
1. 主要結構
網狀構造是腦幹中間部分蓋膜區的特殊結構，基本上它包含一些分佈較為鬆散的神經細胞，擁有相當豐富的樹突和側枝纖維以及大量的傳出與傳入纖維，這是腦幹的特殊構造。網狀細胞的神經元，通常有比較大的細胞核，它的樹突大約有0.5mm長，而它長的軸突會往上下做長距離的傳導。網狀構造的範圍由中腦到延髓，但在間腦的下段及脊髓的上段也有一部分的網狀構造類似神經元。
一般而言把網狀構造的神經核分成四個神經核區：(1)縫核(raphe nuclei)位在於整個腦幹的中央及其偏旁的部分；(2)內側大細胞核(medial gigantocellular nuclei)區，位在於縫核的外側，它含有比較大的細胞核的神經元；(3)外側小細胞核區(lateral parvicellular nuclei)，位在於內側大細胞核區外面；及(4)小腦網狀構造核區，主要與小腦相連接。
2. 傳入神經
網狀構造大部分的傳入訊息由外側小細胞核區接受，再傳到內側大細胞核區，由此向外傳出網狀構造的傳出神經訊息；另外網狀構造接受了所有經過腦幹上行及下行神經樹的側枝訊息，因此，網狀構造可以說是所有神經構造中接受最錯綜複雜及最豐富訊息的神經構造。
通常網狀構造接收到的傳入訊息是屬於它們的側枝傳導，主要傳導很少直接終止在網狀構造；有一部分的神經纖維不會有側枝傳導到網狀構造，這些部分通常是為了維持它們傳導訊息的專一性，其中三個例子是：內側蹄係、視網膜膝距束(retinogeniculocalcarine tract)及聽神經的傳音波定位纖維(tonotopic fibers)。雖然如此，但是傳導聽覺及視覺的系統，另有部分神經纖維經中腦的上丘及下丘到達網狀構造，使得突然間的大聲及閃光會產生反射動作。因此，網狀構造的神經訊息的傳入訊息來自脊髓、腦幹、小腦、邊緣系統、基底核及大腦皮質。網狀構造的傳出訊息幾乎涵蓋了所有中樞神經系統，甚至包括網狀構造自己。
3. 功能介紹
(1) 意識：網狀構造會影響生物個體的意識、注意力、清醒程度及睡醒週期。
(2) 維持體內在環境的平衡(internal homeostasis)：網狀構造調解有關內臟腺體的反射動作，以與維持內在平衡；j與前腦有關的活動，網狀構造會控制呼吸、心跳、血壓、胃腸及泌尿道活動、電解質平衡、瞳孔大小及眼球的運動。k網狀構造的迴路會影響上消化道及呼吸道的反射動作，包括：咳嗽、打噴嚏、吞嚥、嘔吐、打咳、咬合、吸吮、餵食。
(3) 網狀構造會影響運動及感覺反射：網狀構造會影響身體姿勢的反射，改變收縮及伸張肌肉的張力，藉由平衡反射影響眼睛和身體肌肉的關係。
(4) 刺激縫核和腦血管旁邊灰質(peri-aquiduct gray mater)可以達到止痛的效果。
4. 功能分區：一般認定在橋腦的正中央橫切可將網狀構造分成上、下二半部，上半部的網狀構造基本上會影響大腦皮質產生個體的意識狀態維持清醒有關，又稱為上升網狀賦活系統(ascending reticular activating system, ARAS)。
下半部的網狀構造通常對呼吸調節、自動呼吸、運動平衡反射、心血管功能、血壓控制、胃腸反射、泌尿及排便反射有較密切的關係。
上升網狀賦活系統：此系統所在的網狀構造神經元接受多樣傳入神經訊息，包括脊椎視丘徑、三叉神經脊髓徑、孤立徑、前庭核、聽神經核及嗅覺路徑等，其傳出訊息主要經由視丘的層內核(intralaminar nuclei)及視丘下核(sub thalamus)向上傳導多突觸訊息(polysynaptic impulses)到廣泛的大腦皮質，表現意識致活功能。刺激此系統可使個體由睡眠中清醒過來；由1949年Moruzzi和Magoun及往後許多研究者發現，上升網狀賦活系統可以使個體維持意識，保持警覺並與睡醒週期密切相關。當此系統異常時，最嚴重可使個體呈深度昏迷狀態。
破壞下半部的網狀構造會產生的問題如下：(1)異常的呼吸甚至呼吸停止，同時會抑制呼吸相關的反射。(2)經由第7,9,10對顱神經調節的反射會消失。(3)低血壓及(4)霍納氏症候群(Horner syndrome)。
呼吸的神經控制
呼吸是身體吸取氧氣，排出二氧化碳的途徑；由胸部的運動帶動空氣進出肺臟而造成此目的。胸部的運動主要呼吸肌的收縮，其支配的周邊神經主要有肋間神經(支配肋間肌)及膈神經(來自頸髓第3~5節，支配橫膈膜)，而呼吸運動的支配及協調則是位於腦幹的呼吸中樞。
呼吸的功能：個體的呼吸可以提供下列三個重要的功能，即說話、情緒的表達、維持身體的內在平衡(homeostasis)。
說話的功能是由椎體系統控制，自動情緒的表達包括笑、哭、嘆息等等，是由邊緣系統經過椎體外路徑所控制，至於維持氧氣、二氧化碳、酸鹼值平衡的內在平衡系統的功能則是由網狀構造及網狀脊椎路徑所負責，這些神經路徑到最後共同的路線都是到達脊髓的下運動神經元，再經由腦神經、膈神經及肋間神經來達到調節呼吸作用的功能。
一個清醒的人可以自主的控制他的呼吸，這是經由皮質脊徑這條椎體系統所控制，在左側大腦皮質有一個控制語言的中樞，由此中樞經過前腦，在人清醒的情況下可藉由控制呼吸來達到語言的功能。與個體情緒反應有關的邊緣－椎體外呼吸系統，可以影響病人的呼吸狀況，當一個人情緒處於緊張狀況時呼吸會變得急促，緊張過於厲害時會致昏厥，有些病人會在他的二側皮質－延髓路徑受傷害時，導致邊緣系統的過度活動，往往會使他的哭、笑等反應變得特別明顯。當一個人睡眠、昏迷或是廣泛性的大腦疾病時，此椎狀束會被截斷，但呼吸卻不會停止，主要靠的是此一網狀構造使病人能維持自動呼吸。
橋腦至延髓的網狀構造中，有與呼吸控制相關的神經元組成呼吸中樞，可以自動控制呼吸頻率，以維持氧氣及二氧化碳分壓，當上半部網狀構造被破壞呈現昏迷時，呼吸中樞可以維持個體自動呼吸以維持生命，成為所謂植物人的狀態。延髓自動控制呼吸的神經元傳入包括有：(1)其他的網狀構造區域。(2)由大腦皮質下降的運動路徑的側枝，包括有皮質延髓徑、皮質脊徑和邊緣系統。(3)由脊椎向上傳導的感覺路徑包括疼痛刺激及皮膚感覺等。(4)來自胸部與肺部經由第9,10對腦神經傳來的興奮或抑制呼吸反射的訊息。
1. 延髓節律區
延髓節律區(medullary rhythmicity area)之功能為控制呼吸之基本節律。在延髓節律區內有吸氣神經元及呼氣神經元，它們分別組成吸氣區及呼氣區。在正常休息狀態下，吸氣通常約持續2秒鐘，呼氣持續3秒鐘。
呼吸之基本節律是由吸氣區所產生之神經衝動來決定。在呼氣開始時，吸氣區是不活動的，但在3秒鐘後，呼氣動作被抑制，接著開始吸氣。即使吸氣區之所有神經連繫被切斷或阻斷時，此區域仍然有節律的發出衝動以引起吸氣。吸氣區之神經衝動經由膈神經及肋間神經傳送到吸氣肌，使其收縮而產生吸氣。2秒鐘後，吸氣肌又變為不活動，接著開始呼氣，如此呼氣、吸氣有節律地交替發生，即形成基本的呼吸節律。
在平靜呼吸時，吸氣是藉由吸氣肌的主動收縮來完成，呼氣則是吸氣肌鬆弛，使肺及胸腔壁產生被動的彈回而造成；但在用力呼吸時，一般認為來自吸氣區的衝動可活化呼氣區，引發肋間內肌及腹肌的收縮使胸腔變小。
2. 橋腦呼吸調節區
雖然呼吸之基本節律是由延髓節律區所控制，但是神經系統之其他部位可幫協調吸氣與呼氣間之轉換。其中之一為位於上部橋腦之呼吸調節區(pneumotaxic area)，它不斷傳遞抑制性衝動至吸氣區，其主要作用是在週期地限制吸氣，因而促進呼氣。
3. 橋腦長吸區
位於下部橋腦之長吸區(apneustic area)亦可幫助協調吸氣與呼氣間之轉換。此區傳遞刺激性衝動至吸氣區，以活化並延長吸氣，因而抑制呼氣。這作用是發生在呼吸調節區不活動時，而當呼吸調節區活動時，則抑制長吸區之作用。
4. 化學的刺激
呼吸系統的最終目的是維持體內氧與二氧化碳的適當量，因此對血液中氧與二氧化碳的含量非常敏感。在延髓腹部的化學敏感區(chemosensitive area)是H+接受器，它對H+濃度的上升非常敏感，只是H+不能通過血--腦障壁，是由血中的CO2通過血--腦障壁後，與H2O產生反應，形成碳酸(H2CO3)，再解離出H+，而刺激H+接受器，再刺激延髓的呼吸中樞，而使呼吸速率發生改變，故呼吸速率的改變是受H+而非CO2分子的作用。至於頸總動脈分叉處的頸動脈體與靠近主動脈弓處的主動脈體內所含的化學感受器，則對血液中O2含量的變化很敏感，頸動脈體的傳入神經含於舌咽神經內；主動脈體的傳入神經則含於迷走神經內。
在正常環境下，動脈中的PCO2是40mmHg，若超過40mmHg，即會刺激延髓化學敏感區及頸動脈體的化學感受器，而增加吸氣區的活動，致使呼速率增加，以排除較多的CO2，直至PCO2降至正常值為止。若PCO2低於40mmHg，則化學敏感區與化學感受器不受刺激，呼吸速率即會變慢，而使CO2積聚至PCO2超過40mmHg為止。
O2的化學感受器只對PO2大量降低時才敏感，因為PO2降至50mmHg時，血紅素的飽和度還在85%以上，如果動脈血中的由PO2正常的105mmHg突然降至50mmHg時，氧的化學感受器即會受刺激，而將衝動傳至吸氣區使呼吸速率增加；但若PO2降至遠低於50mmHg時，則因缺氧，吸氣區細胞無法對化學感受器的刺激產生良好反應，於是呼吸速率變慢，甚至停止。
在腦幹網狀系統不同層級的病變，會影響呼吸的深度，病變的位置愈低影響的愈大，如果在延髓的網狀構造或延髓頸椎交界處，則會產生完全的呼吸中止(apnea)。
ž參考文獻
1. 洪祖培：昏迷與腦死之評估－與國內外專家學者再論腦死之判定標準。台灣醫界1984;24:39-52。
2. 許世昌：解剖生理學，第八章：神經系統。永大書局，2000；P801-81
許世昌：解剖生理學，第十三章：呼吸系統。永大書局，2000；P1301-29
3. DeMyer W: Neuroanatomy. Chap.8: Brainstem and Cranial nerves. New York: John Wiley & Sons, Inc. 1988; P131-186.
4. Duns P: Topical diagnosis in Neurology, 3rd ed. New York: Thieme Medical Publisher, Inc. 1988.
5. Haines DE: Fundamental neuroscience, 1st edit. Yew York: Churchill Livingstone Inc. 1997.
6. Parnet A: Carpenter’s human neuroanatomy, 9th edit. Baltimore: Williams & Wilkins, 1996.

附錄
【圖一】大腦與腦幹　(出自--昏迷與腦死之評估。台灣醫界1984；27：39-52，洪祖培。)
大腦之功能：思考、記憶、認知、識別、意志、行為、智力、語言、人格、情緒等。
腦幹之功能：大腦與脊髓之間之神經路徑司營自主呼吸、心跳及其他器官之神經中樞司營各種腦幹反射控制意識狀態。

【圖二】腦幹功能之說明圖　(出自--昏迷與腦死之評估。台灣醫界1984；27：39-52，洪祖培。)
大腦與脊髓內之神經路徑

司管各種腦幹反射神經路徑

司管自主呼吸與心跳

序 聖嚴

《做，就對了》是陳辭修先生的第一本書，是他一路走來最真切地體驗。

認識辭修是在精英禪三的時候，憨厚的外表下，卻有著不平凡的人生體驗。在禪修期間是全程禁語的，學員之間沒有例外，最後在心得分享的座談會時，才彼此互相介紹、溝通，這也讓我才開始瞭解到他。

在專業領域裡，他是一位公關及危機處理的高手，常有獨到的見解;這方面的長處與智慧，並不是憑空而來，乃是他一路走來，不斷從做中學習的過程中，創造出人生的價值。

書中提到他每一個時期的經歷，讓人感受到他總是能在陌生的環境中找到個人的模式，在艱辛的任務下，以持續的毅力，不變的決心，加上幽默感，面對一切。從不很懂得，到漸漸熟悉，終於成為業界的翹楚，這不能說是奇蹟，實在是他的努力。值得一提的是在公關策略上，他從不以事件的價值或是市場的眼光，論斷事倩該做或不該做，而是將它的價值建構在公益的本質上。他堅持崇高的理想，接納自己、鼓勵自己，進而接納他人、鼓勵他人；給自己與他人成長的空間，讓自己及周遭的人都成為大有用的人才。

這讓我想起一個小故事......

有一個出家子弟跑去請教一位很有智慧的師父，他跟在師父的身邊天天問同樣的問題：「師父啊!什麼是人生真正的價值？」問得師父煩透了。有一天，師父從房間拿出一塊石頭，對他說：「你把這塊石頭拿到市場去賣，但不要真的賣掉，只要有人出價就好了!看看市場的人出多少錢買這塊石頭。」

弟子就帶著石頭到市場去，有人說這塊石頭很大、很好看，就出價兩塊錢;有人說這塊石頭可以做秤陀，出價十塊錢，結果大家七嘴八舌，最高也只出到十塊錢，弟子很開心的回去告訴師父：「這塊沒有用的石頭還可以賣到十塊錢，真該把它賣了。」師父說：「先不要賣，把它拿到黃金市場賣賣看，也不要真的賣掉。」弟子就把這塊石頭拿到黃金市場，一開始就有人出價一千塊，第二個人出一萬塊，最後被喊到十萬塊。弟子興沖沖跑回去，向師父報告這不可思議的結果，師父就對他說：「把石頭拿去最貴最高級的珠寶商場去估價。」弟子就去了。

第一個人開價就是十萬，但他不賣，於是二十萬、三十萬......一直加到後來對方生氣了，要他自己出價。他對買家說：「師父不許我賣，只是來詢價。」就把石頭帶了回去。回去後對師父說：「這塊石頭居然被出價到數十萬呢，師父。」

師父說：「是啊!我現在不能教你人生的價值，因為你一直在用市場的眼光看你的人生，人生的價值應該是一個人的心中，先有了頂尖的珠寶商的眼光，才可以看到真正的人生價值！」

辭修就是一個堅定自己人生價值的人，從做中造就自己，利益他人，所以我樂意來推薦他寫的這本好書，給更多的人來分享！

INFLAMMATION

INFLAMMATION
The inflammatory response (inflammation) occurs when tissues are injured by bacteria, trauma, toxins, heat, or any other cause. Chemicals including histamine, bradykinin, serotonin, and others are released by damaged tissue. These chemicals cause blood vessels to leak fluid into the tissues, causing swelling. This helps isolate the foreign substance from further contact with body tissues.
The chemicals also attract white blood cells that "eat" microorganisms and dead or damaged cells. The process in which these white blood cells surround, engulf, and destroy foreign substances is called phagocytosis, and the cells are called phagocytes. Phagocytes eventually die. Pus is formed from a collection of dead tissue, dead bacteria, and live and dead phagocytes.

The Human Immune Response System

The Human Immune Response System
An overview of the system
The human immune response system recognizes pathogens and acts to remove, immobilize, or neutralize them. The immune system is antigen-specific (responding to specific molecules on a pathogen) and has memory (its defense to a pathogen is encoded for future activation). The immune system relies on several components to fight an infecting pathogen. T cells are lymphocytes that circulate between the blood, lymph, and lymphoid organs to trigger a systemic immune response with antigen-receptors on the T cell membrane. B cells are lymphocytes that activate the primary immune response when antigens bind to their receptors, causing the B cells to proliferate. Daughter cells of B cells later differentiate into antibody-releasing plasma cells. B cells also comprise the immune system's memory (see diagram).
Antibodies, also called immunoglobulins, are divided into five classes by structure and function, enabling them to recognize a wide spectrum of antigens. Antibody functions include complement fixation that can lead to antigen-cell lysis (rupture) and can cause inflammation. Antibodies also generate a neutralization response where viruses and bacteria are destroyed by phagocytes. Agglutination, or clumping together, of foreign cells are caused by B cells' promotion of complex cross-linking of antibodies binding to antigens. These agglutinated cells are phagocytized. B cells are cloned in massive quantities for a single specific antigen.
Immune response to T. cruzi
The human immune response to T. cruzi infection is inadequate; it provides only a partial defense at best. The immune system's response at its worst causes the defense mechanisms to turn on the body it is intended to protect, thus often causing more harm to the person than does T. cruzi. As T. cruzi immunizes humans to their own antigens, human antibodies attack myocardial and neural cells.
Complement in humans does not become activated solely by T. cruzi invasion; antibodies must be present for complement to bind to a specific T. cruzi antigen. This allows T. cruzi to have time to infect human tissue. Parasite strain and an individual's immune competence are prime factors in determining the T. cruzi's pathology of an individual.
Once infected with T. cruzi, humans acquire partial immunity or resistance to the severe pathologies of Chagas' disease's acute phase through subsequent infections of T. cruzi. This guards many individuals who live in highly endemic areas from the acute symptoms of chagas. Complete removable of the parasite from these individuals would risk the onset of acute chagas through future infection, which is deadly - especially for children.
T. cruzi incorporates certain host cell membrane proteins onto its surface thereby masking its antigenic signal to the immune system's lymphocytes. T. cruzi can also cleave antibody molecules on its surface thereby escaping the immune response's detection. T. cruzi frequently invade monocytes, a circulating phagocyte. Intracellular phagocytosis bring amastigotic T. cruzi into tissue cells where they can proliferate. Once inside tissue cells, T. cruzi are undetected by immune response. Trypomastigotes remain in the blood stream for a short period of time so that the T. cruzi-specific immunoglobulins don't have sufficient time to be activated. T. cruzi employs successful strategies to escape the remarkably potent immune response system. By masking themselves or by eluding the response mechanisms, the parasite is able to adapt to survive and continue the life of the species.
Immune response that damages the human body
Unintentional damage is done to the body's otherwise healthy tissue as the response system attacks what it recognizes as a trigger for a defensive response but does not recognize that it is attacking itself. This is what's known as an autoimmune reaction. Autoimmune responses are responsible in large part for the destructive symptoms of Chagas disease. This pathology is referred to as immunopathology. Severe inflammation occurs around tissue that embody amastigotes as the amastigotes release themselves from the tissue's dead cells. Among the tissue most often encysted is myocardial neural plexes. Plexes are networks of nerves that serve a variety of organs and functions. Digestive system neural plexes are targets as well, namely in the colon and esophagus. During the acute phase of chagas, B and T cells are incited to produce antibodies. Since T. cruzi is able to mask its presence in the blood, these antibodies do not attack T. cruzi but instead go after cell membrane antigenic components called epitopes, that the body's healthy cells and T. cruzi share. Research is being done to isolate the epitope and how T. cruzi uses it to elude recognition by the immune system.
Scientists work to find a cure to T. cruzi's infecting the human species. As research continues into how T. cruzi uses the human body as a host, the disciplines of parasitology and immunology learn much about how these organisms adapt and thrive in changing environments. T. cruzi proves to be a formidable opponent in the fight.