问题 实验题

下图是神经结构模式图,回答下面问题:(4分)

(1)从该反射弧模式图的结构特点分析,该反射弧所能完成的反射类型是           。这是因

                  

(2)若图中5表示该反射活动的效应器,则神经冲动的传导途径是

(1)感受器→(4)_________→(3)神经中枢→(2)___________→(5)效应器

答案

(1)简单反射 该反射弧没有大脑

(2)传入神经 传输神经

题目分析:(1)简单反射与复杂反射的本质区别是否有大脑皮层的参与,没有大脑皮层参与的,神经中枢在大脑皮层以下的反射是简单反射,反射的神经中枢在大脑皮层上的反射是复杂反射,简单反射是指人生来就有的先天性反射,是一种比较低级的神经活动,由大脑皮层以下的神经中枢(如脑干、脊髓)参与即可完成,膝跳反射、眨眼反射、缩手反射、婴儿的吮吸、排尿反射等都是简单反射,复杂反射是人出生以后在生活过程中逐渐形成的后天性反射,是在非条件反射的基础上,经过一定的过程,在大脑皮层参与下完成的,是一种高级的神经活动,是高级 神经活动的基本方式,从图中可以看出从该反射弧模式图的结构特点是神经中枢在脊髓,脊髓的灰质在脊髓中央呈蝴蝶型,白质在周围,因此该反射弧所能完成的反射类型是简单反射;

(2)若图中5表示该反射活动的效应器,则2是传出神经,3是神经中枢、4是传入神经,1是感受器,神经冲动的传导途径是1感受器→4传入神经→3神经中枢→2传出神经→5效应器。

点评:此题是道基础知识题,难度中等,解答此类题目的关键是理解熟记反射的类型和反射弧的概念结构。

问答题

Third-generation corn farmer Paul Siegel says working the land will always be his true love. "There’s nothing like planting a seed, nurturing it and harvesting it," says the owner of Siegel’s Cottonwood Farms in Crest Hill, Ill , near Chicago. ]gut Siegel admits that it is his annual Pumpkin Fest that keeps his farm afloat. Started in 1990, with a pumpkin patch and hayrides, Siegel’s fall festival has mushroomed into a full-fledged theme park complete with haunted barns, a petting zoo, a 10-acre corn maze and snacks Such as smoked turkey legs, kettle corn and funnel cake. The festival attracts more than 30,000 visitors each fall and brings in three times the revenue of Siegel’s 400 acres of corn, soybean and grain crops. "I still get to plant in the spring and harvest in the fall," says Siegel, "but I have four kids to feed and send to college. We have to make it."
For Gia Wilson, 31, who visited the farm with her husband and kids, ages 2 and 5, on a recent Sunday, Cottonwood Farms is just good, old-fashioned fun. "The idea of being outdoors, the animals, the nature—except. for reading about it in storybooks or seeing pictures, this isn’t something the kids would get to experience," she says. Such enthusiasm has helped thousands of farmers like Siegel to thrive in the growing business of agricultural tourism. At a time when profit margins for crops have been slashed razor thin by rising costs, "you have to consider agritainment," says Kay Hollabaugh, president of the North American Farmers Direct Marketing Association. An estimated 62 million people visited farms in 2001, the latest figures available. Annual agritourism revenues range from $20 million in Vermont to $ 200 million in New York. In Hawaii, revenues rose 30%, to $34 million, from 2000 to 2003.
Although there are a few Christmas attractions, such as reindeer and sleigh rides on tree farms, the weeks leading up to Halloween and Thanksgiving are the peak season for agritourism, especially in the Midwest, where the phenomenon is booming. Young’s Jersey Dairy in Yellow Springs, Ohio, attracts more than 1.4 million visitors a year to its dairy farm, which also offers baseball batting cages, a miniature-golf course and homemade ice cream. Eckert’s Country Farm & Stores, near St. Louis, Mo. brings in $10 million annually, about 80% of the farm’s revenues, from its restaurants, bakery and gift shop, according to family member and agritourism consultant Jane Eckert.
To help notoriously private farmers make the transition to the entertainment business, several states have established agritourism offices. This year Pennsylvania created a $150 million fund to provide low-interest loans and grants to farmers hoping to go into agritainment. The state also launched a guide for tourists at blueribbon passport, com. In North Carolina this past summer, with the help of the state agritourism office, Pam Griffin turned a former tobacco field in Fuquay-Varina, 15 miles southwest of Raleigh, into a corn maze shaped like NASCAR driver Scott Riggs’ car.
Griffin and her husband John had never grown corn before, but she decided to learn because she did not want the land that John’s family has owned for five generations to lie fallow. "We don’t want to grow houses. We want to grow crops," says Griffin, who says she spent around $ 30,000 on the maze, which had drawn about 2,000 visitors by mid-October. Griffin did have some setbacks, including an earworm infestation that required spraying. And even though she hasn’t yet turned a profit, she hopes to next year. "People will pay to be entertained," she says.
While most tourists visit farms for a taste of country life, often the experience is not entirely authentic. Bates Nut Farm in Valley Center, Calif., which gets more than 10,000 visitors on weekends in October, doesn’t actually grow any nut trees but sells more than a dozen varieties of nuts that it buys from around the world. The farm does grow 15 acres of "Big Mac" pumpkins weighing 50 lbs. or more, but owner Tom Ness admits that 60% of the pumpkins he sells are shipped in from other growers. "It kind of bums me out that they didn’t grow all their won pumpkins," says Georgia Zarifes, 39, who showed up with friends for the homemade fudge, gifts and jam. "But it’s not going to stop me from coming." Now that’s agritainment.

Why does the author say that often the experience of country life is "not entirely authentic"

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