问题 问答题

简述神经-肌肉接头的传递过程。

答案

参考答案:

神经-肌肉接头传递过程:电-化学-电传递过程. 

运动神经兴奋(动作电位产生)→接头前膜去极化→Ca通道开放,Ca内流→接头前膜内囊泡迁移,与前膜融合→囊泡破裂释放Ach(量子释放)→Ach经接头间隙扩散到接头后膜(终板)→与终板上的Ach受体亚单位结合→终板Na、K通道开放→Na内流为主→终板电位→达阈电位→肌膜爆发动作电位。Ach作用的清除:在胆碱酯酶的作用下分解成胆碱和乙酸,其作用消失。通道开放,Ca内流→接头前膜内囊泡迁移,与前膜融合→囊泡破裂释放Ach(量子释放)→Ach经接头间隙扩散到接头后膜(终板)→与终板上的Ach受体亚单位结合→终板Na、K通道开放→Na内流为主→终板电位→达阈电位→肌膜爆发动作电位。Ach作用的清除:在胆碱酯酶的作用下分解成胆碱和乙酸,其作用消失。

单项选择题 A1/A2型题
阅读理解

Directions: Read the following three passages. Each passage is followed by several questions or unfinished statements. For each of them there are 4 choices marked A,B,C and D. Choose the one that fits best according to the information given in the passage.

Zoo Lights

6pm---10pm Thursdays through Wednesdays, through Jan. 7. The Phoenix Zoo’s 15th-annual holiday light festival features more than 2 million lights and light displays throughout the zoo, as well as a new arctic exhibit and jingo, the talking giraffe. Phoenix Zoo, 455 N. Galvin Parkway, $7 ahead of time. Phoenix. $8 at gate. (602)273-1341. www.phoenixzoo.org.

Cowboy Christmas

5pm---9pm Thursdays, 5pm---10pm Fridays and Saturdays, 5pm---9pm Sundays through Wednesdays, through Jan 1. Rawhide’s Main Street will be lit with 150,000 lights, including a 100-foot tall “tree of lights” and nightly lighting ceremony. Rawhide at Wild Horse Pass, 5700 W. North Loop Road, Gila River Reservation. FREE. (480) 502—5600. www.rawhide.com.

Arizona Celebration of Lights

6pm---9pm Thursdays, 6pm---l0pm Fridays and Saturdays, 6pm---10pm Sundays through Wednesdays, through Jan.1. A 2-mile drive featuring 300 light displays with more than 5 million lights. Community Church of Joy, 21000 N. 75th Ave., Glendale. $12 per car, $8 for adults, free for kids aged 4 and younger, $2 discount with canned food or toy donations. (623)561—0500. www.joyonline.org.

Glendale Glitters Quiet Nights

6pm---10pm Thursdays through Wednesdays, through Jan.6. A display featuring 1.4 million lights decorates downtown Glendale. It also features an animated musical light show in the north part of town. The center of the display is at Murphy Park. Murphy Park, 5850 W. Glendale Ave. Glendale. FREE. (623)930—2820.

Valley of Lights

6pm---12pm Thursdays through Wednesdays, through Dec. 30. A one-mile drive through exhibits featuring more than 100,000 lights and animated displays. Donations accepted. Fain Park, 2200 N. Fifth St., Prescott Valley. FREE. 1一(928)一759—3090. www.pvchamber.org.

小题1:These ads are all about__________.

A.night light displays in the Phoenix Zoo

B.celebrations of lights

C.Christmas activities all over the world

D.advertisements of some products小题2:Which of the following websites can offer you further information about the 100-foot tall “tree of lights”?

A.www. pvchamber. org.

B.www. joyonline. org.

C.www. rawhide.com.

D.www. phoenixzoo.org.小题3:If Mr. Smith and Mrs. Smith drive to Arizona Celebration of Lights with their son aged 5, most probably how much will they pay for the visit at least?

A.$34.

B.$36.

C.$28.

D.$26.小题4:According to the text, which of the following offer animated displays?

A.Zoo Lights & Cowboy Christmas.

B.Valley of Lights & Cowboy Christmas.

C.Zoo Lights & Arizona Celebration of Lights.

D.Valley of Lights & Glendale Glitters Quiet Nights.小题5:What’s the purpose of the text?

A.To attract more visitors to these activities.

B.To collect more donations from the visitors.

C.To let kids have an interesting Christmas Day.

D.To earn more money.