Birds, like all vertebrates, consist of a number of systems that each operate independently or with each other to provide for the normal activity and functioning of the animal as a whole. The major body systems are:

Integumentary (surface of the bird)Skeletal SystemEmbryology of the chickenCirculatory systemDigestive systemEndocrine systemExcretory systemImmune systemMetabolic systemMuscular systemNervous systems & important sensory organsRespiratory system & thermoregulationReproductive system