问题 选择题

下列有关人体神经调节的叙述中,不正确的是(  )

A.反射是通过反射弧完成的.完成反射活动,反射弧必须完整

B.脊髓内的神经中枢受大脑的调节和控制.脊髓被横断的患者,将会表现出大小便失禁

C.在以肌肉为效应器的反射弧中,如果仅传出神经受损,当感受器受到刺激后,将表现为有感觉但肌肉不收缩

D.与其他各类细胞相比,神经元在结构上的显著特点是:接受刺激,产生兴奋和传导兴奋

答案

A、神经调节的基本方式是反射,反射是通过反射弧这种神经结构来完成的,反射弧必须完整才能完成反射,故该选项不符合题意;

B、脊髓包括灰质和白质两部分,灰质在中央,呈蝶形,在脊髓的灰质里,有许多低级的神经中枢,可以完成一些基本的反射活动,如膝跳反射、排便反射、排尿反射等,脊髓里的神经中枢是受大脑控制的;白质在灰质的周围,白质内的神经纤维在脊髓的各部分之间、以及脊髓与脑之间,起着联系作用.因此脊髓具有反射和传导功能.脊胸段脊髓完全横断的病人,排便、排尿中枢并没有损伤,完成排便、排尿反射的反射弧也还完整,脊髓的反射功能也没有丧失,只是位于脊髓下端的排便中枢和排尿中枢失去了大脑的控制,因此出现大小便失禁.故该选项不符合题意;

C、神经调节的基本方式是反射,反射活动的结构基础称为反射弧,包括感受器、传入神经、神经中枢、传出神经和效应器.反射必须通过反射弧来完成,缺少任何一个环节反射活动都不能完成,如传出神经受损,即使有适宜的刺激人体也不会作出反应,因为效应器接收不到神经传来的神经冲动;但是感受器产生的神经冲动能通过传入神经传到脊髓内的神经中枢,在经过脊髓的白质能上行传到大脑皮层,形成感觉.故该选项不符合题意;

D、神经元与其他种类的细胞相比较,在结构上的显著特点是具有突起.故该选项符合题意;

故选D

选择题
阅读理解

阅读理解。

    Parents often believe that they have a good relationship with their teenagers (青少年). But last summer,

Joanna and Henry noticed a change in their elder son: suddenly he seemed to be talking far more to his friends

than to his parents. "The door to his room is always shut." Joanns noted.

    Tina and Mark noticed similar changes in their 14-year-old daughter. "She used to cuddle up (蜷伏) with

me on the sofa and talk," said Mark. "Now we joke that she does this only when she wants something,

Sometimes she wants to be treated like a little girl and sometimes like a young lady. The problem is figuring

out which time is which."  

    Before age 11, children like to tell their parents what's on their minds. "In fact, parents are first on the list."

said Michael Riera, author of Uncommon Sense for Parents with Teenagers. "This completely changes during

the teen years." Riera explained. "They talk to their friends first, then maybe their teachers, and their parents

last."

    Parents who know what's going on in their teenagers' lives are in the best position to help them. To break

down the wall of silence, parents should create chances to understand what their children want to say, and try

to find ways to talk and write to them. And they must give their children a mental break, for children also need

freedom, though young. Another thing parents should remember is that to be a friend, not a manager, with

their children is a better way to know them.

1. "The door to his room is always shut" suggests that the son _____. [ ]

A. is always busy with his studies   

B. doesn't want to be disturbed (打扰)   

C. keeps himself away from his parents   

D. begins to dislike his parents

2. What troubles Tina and Mark most is that _____. [ ]

A. their daughter isn't as lovely as before   

B. they can't read their daughter's mind exactly (确切地)   

C. they don't know what to say to their daughter   

D. their daughter talks with them only when she needs help

3. Which of the following best explains "the wall of silence" in the last paragraph? [ ]

A. Teenagers talk a lot with their friends.   

B. Teenagers do not want to understand their parents.   

C. Teenagers do not talk much with their parents.   

D. Teenagers talk little about their own lives.

4. What can be learned from the passage? [ ]

A. Parents are unhappy with their growing children.   

B. Parents have suitable ways to talk with their teenagers.   

C. Parents should be patient with their silent teenagers.   

D. Parents should try to understand their teenagers.