An organ is a part of a multicellular organism, formed by various tissues and acting as a whole when performing a complex function.
In the body of animals, the following organ systems usually interact: musculoskeletal, digestive, respiratory, excretory, circulatory, reproductive, nervous and endocrine.
The musculoskeletal system consists of the skeleton and the muscles that are attached to it. This system performs supporting, motor and protective functions in the animal’s body.
The digestive system consists of organs that provide chopping and digestion of food, absorption of nutrients and removal of undigested residues from the body.
The excretory system serves to remove excess water and harmful metabolic products from the body. The circulatory system provides the movement of blood throughout the body.
Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.