人有幾多細胞嫁？

人由細胞所構成。究竟人體細胞數量有多少，至今還沒有一個確實的數字，一般有60兆至300兆。

其中分為100多種細胞，組成各類組織語器官。例如血液細胞就是其中一種。血液細胞分分秒秒都在進行新陳代謝，經歷死亡再生的過程。每秒鐘就有7.000.000.個新的紅血球誕生，代替死亡的紅血球。紅血球的壽命只有120天，白血球9天，血小板4天。

● 人出生時大約有1,000億個腦細胞，而到一百歲時，大部份人依然擁有963.5億個。

妊娠第20天左右，胚胎中的大腦原基存在。
2個月時，大腦裏溝回的輪廓已經很明顯。
3個月時，腦細胞的發育進入第一個高峰時期。
4-5月時，腦細胞仍處于高峰時期，幷偶爾出現記憶痕迹。
6個月時，大腦表面出現溝回，大腦皮層的層次結構也基本定形。腦細胞140億個，具備了一生的腦細胞數量。
7個月時，胎兒大腦中的主持知覺和運動的神經已經比較發達，開始具有思維和記憶的能力。
8個月，胎兒的大腦皮層更爲發達，表面的主要溝回已經完全形成。
人出生時大約有1,000億個腦細胞，而到一百歲時，大部份人依然擁有963.5億個。

That's a very good question, and we applaud your class for its inquisitiveness. We knew there were a lot of cells in the human body, but we were hard pressed to put an actual number on it. It seemed like a fairly straightforward query, so we tried a straightforward approach and typed "number cells human body." Our results were numerous and informative, but after flipping through them, we learned there really is no consensus on the answer.
Some sources told us that the average adult human body is made up of "50 million million" (50 trillion) cells, while others put the figure closer to 10 trillion. Science NetLinks, a resource for science teachers, stated that there are approximately "ten to the 14th power" (that's 100 trillion) cells in the human body.
Keep in mind, all of these figures are just estimates. At this time, there really is no way to know the exact number of cells in a human body. Can you imagine trying to count them all? Plus, as one source pointed out, the number will vary from person to person, depending on their size. The number of cells in your own body is constantly changing, as cells die or are destroyed and new ones are formed. So even the number of cells in your own body is not static.
For a host of other cell resources, stop by the Yahoo! Cell Biology category. You'll learn more than you can imagine about those "building blocks of life."

以下資訊提供你參考，希望可以回答你的問題。

圖片參考：http://mmh.banyu.co.jp/media/mmhe2/figures/fg001_2.gif

細胞的形狀、大小其實差異極大。神經細胞很長、表皮細胞很扁平、紅血球像圓形救生艇、白血球會變形、肌肉細胞會伸縮等。人體有多少細胞呢？根據統計估算，大約有10兆個細胞。

人類的身體上約有多少個細胞!!???

答：
人由細胞所構成。究竟人體細胞數量有多少，至今還沒有一個確實的數字，一般有60兆至300兆。

其中分為100多種細胞，組成各類組織語器官。例如血液細胞就是其中一種。血液細胞分分秒秒都在進行新陳代謝，經歷死亡再生的過程。每秒鐘就有7.000.000.個新的紅血球誕生，代替死亡的紅血球。紅血球的壽命只有120天，白血球9天，血小板4天。

人有細胞大概一億億個

人既細胞會分裂同死亡~所以好難講wo~我好肉記得有幾千億個