胎盘及相关结构 -- -- 高级

How does a developing baby breathe?
::一个正在发育的婴儿如何呼吸?

Or eat? From mom of course. Shown here is a detailed representation of the placenta . And this is where all these interactions occur.
::当然是妈妈送的,这里是胎盘的详细描述。这就是所有这些相互作用发生的地方。

Placenta and Related Structures
::胎盘及相关结构

The placenta is a temporary organ in which nutrients and wastes are exchanged between the mother and the embryo or fetus . The placenta begins to form in the second week after . It continues to develop and grow to meet the needs of the growing fetus. A fully developed placenta is made up of a large mass of from both the mother and the fetus. The maternal and fetal vessels are close together but separated by empty space. This allows the mother’s and fetus’s to exchange substances without actually mixing.
::胎盘是一种临时器官,母亲与胚胎或胎儿之间可以交换营养和废物。胎盘在第二个星期后开始形成。胎盘在继续发育和成长,以满足不断成长的胎儿的需要。完全发达的胎盘由母亲和胎儿的大批婴儿组成。母体和胎儿的血管相互接近,但被空地隔开。这使得母亲和胎儿可以在不实际混合的情况下交换物质。

How the Placenta Works
::Plenta 如何工作

Blood from the mother enters the maternal blood vessels of the placenta under pressure, forcing the blood into the empty spaces. When the mother’s blood contacts the fetal blood vessels, gases are exchanged. Oxygen from the mother’s blood is exchanged with carbon dioxide from the fetus’s blood. A release of pressure brings the mother’s blood back from the placenta into her veins .
::母亲的血液在压力下进入胎盘的母血管,迫使血液进入空隙。 当母亲的血液接触胎儿血管时,气体会相互交换。母亲血液中的氧与胎儿血液中的二氧化碳相互交换。 释放压力将母亲的血液从胎盘带回她的血管。

The fetus is connected to the placenta through the umbilical cord , a tube that contains two arteries and a vein. Blood from the fetus enters the placenta through the umbilical arteries, exchanges gases with the mother’s blood, and travels back to the fetus through the umbilical vein.
::胎儿与胎盘有关联,通过子宫颈带连接。 胎盘中含有两条动脉和血管。 胎儿的血液通过宫颈动脉进入胎盘,与母亲的血液交换气体,通过细胞血管返回胎盘。

In addition to gas exchange, the placenta transfers nutrients, , and other needed substances from the mother’s blood to the fetus’s blood. The placenta also filters many harmful substances out of the mother’s blood, so they are not transferred to the fetus. In addition, the placenta secretes hormones that maintain the corpus luteum in the mother’s ovary . Recall that the corpus luteum secretes progesterone , which is needed to keep the endometrium of the uterus from breaking down.
::除了气体交换外,胎盘将营养素、其他所需物质从母亲的血液转移到胎儿的血液中。胎盘还将许多有害物质从母亲的血液中过滤出来,因此不会转移到胎儿身上。 此外,胎盘分泌了保持母亲卵巢中月球元素的荷尔蒙。 回顾乳液分泌蛋白酮(prognesterone)是防止子宫内子宫破裂所必需的。

Amniotic Sac and Fluid
::羊水和氟化物

Attached to the placenta is the amniotic sac , which surrounds and protects the embryo or fetus. It begins to form in the second week after fertilization. It soon fills with and dissolved substances to form amniotic fluid . The fluid allows the fetus to move freely until the fetus grows to fill most of the available space. The fluid also cushions the fetus and helps protect it from injury.
::胎盘附在胎盘上,它环绕并保护胚胎或胎儿,在受精后第二周开始形成,它很快会填充和溶解物质以形成羊膜液,液体允许胎儿自由行动,直到胎儿长大以填充大部分现有空间。液体也让胎儿缓冲,帮助保护胎儿免受伤害。

Summary
::摘要

播放段落
• The placenta is a temporary organ in which nutrients and wastes are exchanged between the mother and the embryo or fetus.
  ::胎盘是母亲与胚胎或胎儿之间交换养分和废物的临时器官。
播放段落
• Blood from the mother enters the maternal blood vessels of the placenta under pressure, forcing the blood into the empty spaces. A release of pressure brings the mother’s blood back from the placenta into her veins.
  ::母亲的血液在压力下进入胎盘的母血管,迫使血液进入空洞空间。 释放压力将母亲的血液从胎盘带回她的血管。
播放段落
• The placenta also filters many harmful substances out of the mother’s blood, so they are not transferred to the fetus, and maintains the corpus luteum in the mother’s ovary.
  ::胎盘还将许多有害物质从母亲的血液中过滤出来,所以它们不会转移到胎儿身上,并在母亲的卵巢中保留细胞润滑剂。

Review
::回顾

播放段落
1. What connects the placenta to the fetus?
   ::胎盘和胎儿之间有什么联系?
播放段落
2. What roles does the placenta serve other than the exchange of gases and nutrients?
   ::除了交换气体和养分之外,胎盘还能起到什么作用?
播放段落
3. What role do the amniotic sac and amniotic fluid play?
   ::羊水和羊水能起什么作用?