题干

健康成年人饮用1000mL清水后1﹣2小时内,尿量显著增多,而饮用等量的生理盐水后,尿量变化幅度不大,回答下列问题:

(1)饮用1000mL的清水后,尿流量增多的原因是细胞外液____ 下降,下丘脑分泌的____ 减少,____ 对水的重吸收减少.

(2)当膀胱中尿液充盈时,膀胱中的相应感受器就会感受到刺激,产生____ 并传递到脊髓腰段的排尿中枢,且能上传到大脑皮层,产生尿意.如果排尿条件不成熟,大脑能抑制脊髓排尿中枢,这体现了神经调节具有____ 的特点.

(3)如果某人胸部脊髓因外伤而截断,排尿反射可以完成吗?请简要说明原因____ .

上一题 下一题 0.0难度 选择题 更新时间:2015-09-07 04:42:50

答案(点此获取答案解析)

渗透压,抗利尿激素,肾小管和集合管,神经冲动,分级调节,可以,排尿反射的反射弧还是完整的

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根据短文内容的理解,选择正确的答案。   

    Outside her shabby cottage, old Mrs. Tailor was hanging out laundry on a wire line, unaware that some children lay hidden in the leaves of a nearby tree watching her every move. They were determined to find out if she really was a witch.

    They watched as she took a broomstick to clean the dirt from her stone steps. But, much to their disappointment, she did not mount the broomstick and take a flight. Suddenly, the old lady's work was interrupted by the cackling of her hen—a signal that an egg had been laid in the warm nest on top of the haystack.

    The old broomstick was put aside as she hobbled off towards the haystack followed by Sooty, a black cat she had rescued from a fox trap some time back. With only three legs, it was hard for Sooty to keep up with the old lady. The cat provided proof—the children were sure that only a witch could own a black cat with three legs.

    There, standing on a wooden box, was Mrs. Tailor, stretching out to gather her precious egg. Taking the egg in one of her hands, she began to climb down when, without warning, the box broke and the old lady fell.

    "We have to get and help her," whispered Amy.

    "What if it is a trick?" replied Ben.

    "Don't be silly, Ben. If she were a witch, she would have turned us into frogs already," reasoned Meg. "Come on, Amy, let's go." The girls climbed down the tree and ran all the way to the haystack.

    Approaching carefully, they could see a wound on the old lady's face. She had knocked her head on a stone and her ankle was definitely broken. "Go and get Dad," Amy yelled to her brother. "Tell him about the accident."

    The boys did not need another excuse to leave. They ran as fast as they could for help, hoping that Mrs. Tailor would not wake and turn the girls into frogs.