What is composed of the respiratory system?
The upper respiratory system (where air enters and exits the body) is composed of the nasal cavity, pharynx, and larynx. The lower respiratory system (where the air moves to be processed) consists of the trachea, the bronchi, and the lungs. So the answer is either the nose and mouth, or the trachea, depending on how you meant the question.
It is the beginning part of the respiratory system that is involved in inhalation. The important functions of nose are to filter the atmospheric air before passing it further into the respiratory system and to provide the sense of smell.The structure of a human nose is composed of bones, cartilage and fibro fatty tissues.
The respiratory system works with almost all the other body systems in the human body. For Example: The respiratory system works with the nervous system because the brain tells the respiratory system when to breathe in or breathe out. The respiratory system works with the skeletal system, by allowing the skeletal system to protect the respiratory organs, like how the ribs protect the lungs.