问题 问答题 简答题

黄体是怎样形成的?什么叫妊娠黄体?黄体的功能有哪些?黄体是如何退化的?

答案

参考答案:

(1)黄体的形成:成熟卵泡排卵后,残留在卵巢内的卵泡壁塌陷,卵泡膜内的血管和结缔组织伸入颗粒层,在LH的作用下,卵泡壁的细胞体积增大,分化为一个体积很大并富含血管的内分泌细胞团,形成黄体。

(2)黄体的功能:分泌孕激素和雌激素。

(3)妊娠黄体:卵细胞若受精,黄体在胎盘分泌的绒毛膜促性腺激素的作用下继续发育增大,称妊娠黄体。

(4)黄体退化:如果卵子未受精,在排卵后数天黄体细胞脂肪变性,空泡化,核萎缩,,颗粒细胞为结缔组织所代替,血管减少,颜色消退,形成斑痂。

阅读理解

“Why does the chicken cross the road? To get to the other side!”

That’s an old joke in the west, but it came to my mind again when I saw people crossing the road at the intersection of Shanxi Road and Huaihai Road in Shanghai.

When the traffic light was red, a group of people were waiting for the light to change. Suddenly one man began rushing to the other side of the road. Soon others followed him at the crossing and more people did the same. Just like chickens, they didn’t mind the honking horns(喇叭声) and kept crossing the road in a mess.

Every year several thousand people are either killed or hurt on the roads in Shanghai. And at least one third of them were jaywalking(乱穿马路). Jaywalking is very common in Shanghai. It seems that jaywalkers are not afraid of the danger to themselves.

Traffic laws are to keep people safe. So we should obey them, and have good road-crossing habits. When someone starts to jaywalk, we should stop him, and never follow him. That way we can avoid the traffic accidents.

小题1:The underlined word “intersection” here probably means “       ”.

A.road

B.bridge

C.crossing

D.traffic小题2:The writer saw people      in Shanghai that day.

A.crossing the road in a mess

B.waiting for the green light patiently

C.crossing the road with chickens

D.hurting each other in the street小题3:How does the writer like what he saw in Shanghai that day?

A.He thinks it’s OK.

B.He thinks it’s wrong.

C.He has no idea of it.

D.He doesn’t mention it

单项选择题