Part of Biology (Single Science) Cells, organ systems and ecosystems The air that enters the nasal cavity flows down the trachea. The trachea has a number of adaptations: cartilage rings in the walls ...

The trachea is a tube-like structure in the neck and upper chest. It stretches from the larynx, or voice box, to the bronchi and transports air to and from the lungs when a person breathes. When a ...

Alveoli are tiny air sacs in your lungs that take up the oxygen you breathe in and keep your body going. Although they’re microscopic, alveoli are the workhorses of your respiratory system. People ...

Lung damage causes proliferation of P63-expressing cells in bronchioles, migration to damaged tissue, and regeneration of alveoli. Scientists have identified a subset of stem cells in rodents and in ...

Respiration is a chemical reaction that happens in all living cells, including plant cells and animal cells. It is the way that energy is released from glucose so that all the other chemical processes ...