1. Types of respiration
- Cellular respiration – The chemical breakdown of food substances to yield ATP (aerobic and/or anaerobic)
- Gas exchange – Different organisms use different kinds of breathing apparatus in order to transport oxygen throughout its body
2. Evolutionary adaptations of gas exchange systems and respiration
- Different plant adaptations in acquiring CO2 from the environment evolved (C3, C4 and CAM pathways).
- Structural adaptations of respiratory apparatus depend on the animal’s habitat. The three most common respiratory organs are gills, tracheae, and lungs
- The respiratory system and circulatory system cooperate directly with each other.
3. Mammalian respiration
- The respiratory system is divided into the upper respiratory tract (nasal passages, mouth, throat, larynx and trachea) and lower respiratory tract (bronchi and the lungs).
- Air enters (inhalation) the respiratory system due to a pressure drop inside the lungs (negative pressure).
- Air exits (exhalation) the respiratory system due to an increase in pressure inside the lungs.
- Breathing is regulated by control centers in the brain (medulla oblongata and pons.)
- Gases are transported via passive diffusion throughout the body.
4. Respiratory diseases and their prevention
- Respiratory disorders may be congenital or environmental.
- Respiratory disorders can be prevented through a combination of proper diet and lifestyle change.