"Transportation in the human body substances" and "discharge of body waste" is important and difficult of human life activities, is an important chapter in the examination of many years. Content abstract, knowledge and more difficult for students to understand, so we are in the review process, we should grasp the overall body of knowledge, good at summing up the law and root out the textbook illustration of tacit knowledge, deepen the links between knowledge, in order to achieve more with less review results.
One. Transport the body substance
Heart structure and blood circulation is the difficulty of this chapter, in the review process, I mainly help students find the law of memory, abstract and difficult effort to systematize knowledge, allow students to remember formulas, in order to achieve good results review.
For each chamber of the heart wall thickness may be summarized as follows: chamber room thin thickness, left and right thin thickness, a blood feed near the thin wall, the wall thickness is sent to the blood away. Heart blood is: move left and right static. The heart of the connected blood vessels: even quiet room, room linked. Law of blood flow in the circulation and blood vessels of the variation: in dynamic circulation dynamic and static in static, dynamic static variable; pulmonary circulation in dynamic static, static in the dynamic and static changes. In the review the use of the blood circulation path animation to help students understand the changes and blood components blood circulation occurs, then let the students then each of the structures on the animated characters trying to replace tell me, and then let the students through further Solitaire game proficiency in two ways circulation of blood through the blood circulation figure also enable students to understand the systemic and pulmonary circulation are linked at the heart, consisting of a complete cycle routes. Allow students to experiment in the review of blood pressure measurement pulse and clear measurement of blood pressure at different positions, respectively, wrist and upper arm brachial artery radial artery. So that we can put the knowledge scattered strung lines, easy to remember, but also deepened the impression.
two. The body of waste discharge
First, let students know the name of the urinary system and the role of the various parts of the figure, is clearly kidney organogenesis urine.
Form the structure of the nephron and urine is heavy and difficult chapter, students difficult to understand, I am also help students find the law which, tap the implicit knowledge by observing the nephron mode map, can find a lot of hidden knowledge points. Two capillary network is formed in a nephron: glomerular capillary and the outer capillary tubules, changes in blood capillaries at the outer tubule, becomes the arterial blood. So in the renal artery, afferent arterioles, glomerular efferent arterioles are arterial blood flow; blood flow in the renal vein. And renal vein blood in the most obvious features are: reduction of urea and other waste. Both ends connected glomerular capillary arteries capillaries, the capillaries are connected to both ends of the efferent arteriole is a blood vessel. Such a find, a summarized, a summary, a comb, students are naturally very easy to understand the characteristics of blood vessels and blood flow characteristics of renal units, and had a good groundwork for the formation of the next review of urine.
Blood, blood plasma components, the original urine, urine often examine our knowledge, four kinds of liquid components need to be clear. Components of the blood are: blood cells, large proteins, water, inorganic salts, glucose, urea; plasma components: macromolecular proteins, water, inorganic salts, glucose, urea; original urine ingredients are: water, salt, dextrose, urea; composition of urine are: water, inorganic salts, urea. These four components clear liquid, so that the difference between the title four kinds of liquid ingredients to clear out. Wherein no original urine blood cells and large proteins, because the blood cells and glomerular filtration can not be large proteins. No urine glucose, because the original glucose in urine are all tubular reabsorption. An increased concentration of the protein molecules of efferent arterioles, the glomerular filtration rate because a lot of water, but protein molecules can not be filtered. Increased urea concentration in urine, because the majority of tubular reabsorption of water, and urea can not be reabsorbed. After forming a complete review of the urine, urinary system allows students to combine their own will be able to tell the discharge route map urine, urination and summarizes the significance of the human body.
Through our summarized, constitutes the formation of kidney and urinary units will have a comprehensive understanding.
three. The integrated use of "mass transport" and "the formation of urine" to solve practical problems
After review of the basics, the two parts can be linked to knowledge through practice. There are textbooks such a good after-school problem: molecular pathways of urea excreted liver cells to produce what? Let the students try to form blood circulation and discharge of urine and knowledge to solve a place that's not right complement each other, so that a few students answer, supplement, the problem is solved. Students suddenly realized that the "trail" and "urinary tract" is also linked. Enhance the ability of students to the integrated use of knowledge to solve practical problems.
Thus, we are in the review process, we must be good at ferreting out textbooks, find the law to find the intrinsic link between knowledge, knowledge of the dolphin pearls, necklaces, will be more dazzling.
Published in the "New Curriculum junior high school biology teaching case" 2011 Year 6 Qi