There is an urgent need for information about the flight characteristics of domestic pigeons in shape, wings, bones, muscles, breathing and so on.

1. The body is streamlined. Please explain the relationship between the appearance of domestic pigeons and flying life. (Spindle streamlined body)

Type A, reducing air resistance in flight. )

2. The body surface is covered with feathers. Pigeons are covered with feathers except their feet. Feathers are mainly divided into normal feathers and down.

Feather. Feathers on the front cover the body surface to form a windbreak shell, which can streamline the body and make the front the largest.

Feathers are distributed on wings and tails. Please think about what this means for flying. (It is beneficial to the flight and palm of domestic pigeons.

Keep your body in balance. Students wear down jackets in winter, which are light, soft and warm. The down in the down jacket belongs to the domestic duck.

Feathers, densely born under feathers, can keep the temperature and reduce the heat dissipation of domestic pigeons when they fly in the sky.

Lost, resist the cold.

3. The front legs become wings. Wings are the flying organs of domestic pigeons. When the wings are spread out, they have a large area and can fan the air.

Fly. Pigeons not only have many characteristics to adapt to flying life in external form, but also some characteristics in their internal structure are related to

Adapt to flying life.

Second, bones and muscles

Demonstrate the pigeon's skeleton wall chart and specimen.

1. The bone is light and healed, with thin bone fragments and hollow long bones. What are the characteristics of pigeon bones to flying life?

Meaning? (Student answer: lose weight and strengthen firmness. )

Please look at the picture on page 8 1 in the textbook. Which bone is the most developed? Guide students to observe the sternum and its characteristics.

The sternum is the most developed, and it forms a protuberance outward, which is called keel process. What is the meaning of flying? (Guide students.

Recognize that developed muscles are attached to developed sternum. )

2. The pectoral muscles are developed, which affects the two wings to complete the flight action. The pectoral muscles of domestic pigeons are particularly developed, accounting for about 10% of the body weight.

1/5, which is unmatched by other animals. Pigeons lift their wings up or down with the help of developed pectoral muscles.

Falling, flapping, flying in the sky.

Pigeons need to consume a lot of energy because of flying, so they need to constantly take food from the outside and supplement their nutrition.

Analysis of the digestive function of domestic pigeons can be summarized as follows: large appetite, strong digestive ability, and supplementing camp consumed in flight.

Improve; Toothless, short and thick large intestine, no storage of feces, excretion at any time, conducive to weight loss, easy to fly.

Pigeons need not only a lot of food but also a lot of oxygen in flight life. Therefore, domestic pigeons

The respiratory system is developed and the breathing mode is unique. Breathe with the lungs, and at the same time use the airbag to assist breathing.

(Airbags can store oxygen) Do you know? Pigeons consume less oxygen in flight than in static flight.

More than 20 times more than when it stopped living. Which structures of domestic pigeons can meet the body's demand for oxygen? Airbags can reduce weight.

Body specific gravity; It is beneficial to reduce the friction between internal organs and to dissipate heat in the body.