@3、骨骼特点: 骨骼为轻而坚的气质骨,脊椎头骨多愈合,胸骨具龙骨突, 开放式骨盆。 conarD Figure 33-26 A pigeons skeleton shows several adaptations for flight. The large, keeled breast- bone serves as an attachment point for flight muscles.The collarbone helps absorb the Breastbone stresses of flight Reptiles and Birds 7
6 3、骨骼特点： 骨骼为轻而坚的气质骨，脊椎头骨多愈合，胸骨具龙骨突， 开放式骨盆
@4、呼吸特点: 壽肺:小,结构特殊,缺乏弹性的实心海绵体,有毛细支 气管组成完整的气管网,毛细支气管周围放射排列的微 气管,其上富有微血管,是肺气体交换的功能单位,相 当哺乳动物的肺泡,但结构不同 气囊:气囊是气管分支的一部分,即中、次支气管伸出 肺外,末端膨大的膜质囊,通入皮下、肌肉和骨腔中。 气囊的功能: 双重呼吸:
7 4、呼吸特点： 肺：小，结构特殊，缺乏弹性的实心海绵体，有毛细支 气管组成完整的气管网，毛细支气管周围放射排列的微 气管，其上富有微血管，是肺气体交换的功能单位，相 当哺乳动物的肺泡，但结构不同。 气囊：气囊是气管分支的一部分，即中、次支气管伸出 肺外，末端膨大的膜质囊，通入皮下、肌肉和骨腔中。 气囊的功能： 双重呼吸：
Avian Lung Structure Win When a bird inhales, air flows past the lungs directly into the poster nor nir sacs Ante air 5acs Windon Anterior air sacs Posterior air sacs When the bird exhales. air flows from the postenor air sacs forward into the lung Air then Rows into the antenor air sacs in front of the lungs when the bird inhales The air then passes out of the body ith the next exhalation
8
Lung containing () Cycle I in bone Antrior Interior Airsacs Anterior Posterior air sacs air sacs Bird Air fr Parabronchus Cycle 2 e Anterior Posterior s nerm Posterior Air pillar 39.9 Air Flow Through Bird Lungs Is Constant and Unidirectional unque to bird anatomy. (b) The gas-exchange surfac of mammals are alveoli, which are blind sacs, so al 3 are air capillaries branching off the parabronchi that run flow must be tidal. The gas-exchange surfaces of birds through the lungs. (e) The unidirectional flow of air dur- ng avian respiration
9