The task of the lesson: to give an idea about the phases of the heart (the rhythm), the nervous and humoral regulation of the heart.
Equipment. Demonstration material: tables: "Phases of the heart", "human heart", "circulation scheme", the movie "The Structure and work heart "(1st fragment); metronome or clock with a second hand.
Handout (4-6 people): saline (0,6% NaCl); pipette, an aqueous solution (1: 10000) adrenaline, bath with decapitated and dissected a frog, a solution of nicotine.
Learning new material.
Humoral effects on the heart frog. Lab work Investigational or demonstration experiments conducted by the teacher. The work of the human heart.
Nervous and humoral control of his work. The movie. 2. Consolidation. Independent work — filling in the table on the film and with the textbook.
In forming ideas about the phases of the cardiac cycle and humoral regulation of the heart must be given the opportunity for students to observe the activity of frog heart and its changes under the influence of chemical substances. This helps in the absorption of difficult questions about the rhythm of the heart and of the humoral influence on him. At the beginning of the lesson, students perform lab tests or teacher shows himself.
1. Find the atrium and ventricle of the heart of a frog. How do they differ in color?
2. Follow the sequence of the heart rate and total relaxation of the heart muscle.
3. Calculated (by the hour or a metronome), how many times in 30 seconds reduced heart frogs, and write in their notebooks.
4. With a pipette to apply a drop of frog heart of an aqueous solution of adrenaline. How has the rate cuts? Record.
Rinse off with heart adrenaline saline solution.
5. Apply on heart Frogs drop of alcohol. Count the number of cuts and re-record. Rinse with alcohol, saline solution.
6. Apply a drop of nicotine. Let us see how it works on the heart frog.
7. The overall conclusion how the cardiac activity of the various impacts.
After working some students talk about the results of their observations and the teacher's questions, how changes work frog heart under the influence of the effects of adrenaline, alcohol and nicotine, the students meet certain specific conclusions, and then make a general conclusion about the effects of chemicals. Teacher defines humoral regulation.
Before watching the movie "The Structure and work heart, "the teacher conducts a brief introductory conversation.
"We'll see how it works heart person, whether or not it always works the same way, why it can work almost tirelessly throughout the life of man. " Draws on the board table. At the end of the lesson, students will fill it yourself.
The phases and their duration
What happens in the heart atria I II III
Students then view the movies.
At the end of the lesson, students draw a chart in their notebooks, using the figure 81 textbook and film, fill it, and report on progress, provide examples of the nervous regulation of the heart, draw a reflex arc on the board. All students redraw the reflex arc in the notebook.
Summing up the lesson, the teacher talks about the work of Pavlov associated with innervation of the heart, of the interaction of the nervous and humoral regulation, so that the heart carefully and sparingly spends his strength.
Instead the film can be shown kinokoltsovku "Stroke of the heart", where each bar denotes the corresponding number. After watching kinokoltsovki students must decide under what figure what time indicated.
Job at home: Article textbook "Work the heart. "