通过观察血液在动脉、静脉及毛细血管内的流动情况,学生进一步了解到动脉、静脉及毛细血管的构造特点与其机能的相一致性。通常采用观察鱼尾鳍、蛙的蹼、蛙的肠系膜等材料来做这个实验。考虑到这些材料都很薄,内有毛细血管网,在显微镜下可以直 By observing the flow of blood in arteries, veins, and capillaries, students further understand the structural characteristics of arteries, veins, and capillaries that are consistent with their function. This experiment is usually performed using materials such as fish tail fins, frog tadpoles, and frog mesenteries. Considering that these materials are very thin, there are capillary networks inside and can be straightened under the microscope