Respiration And Breathing

The process that releases energy from food

Glucose + Oxygen - Carbon dioxide + Water + Energy

Needs oxygen to release energy from food

Does not use oxygen to release energy from food

Oxygen is carried by the haemoglobin in red blood cells to all cells of the body.

Yeast converts sugars to alcohol in “Fermentation” - this produces alcohol for drinks such as beers and wines!

We are supposed to inhale through our nose. The reasons for doing this are: • Hairs and mucus trap dirt particles and bacteria in the nose. • Air is warmed and moistened as it passes through the nose. Warm and moist air helps oxygen to pass from the lungs into the bloodstream more easily.

The trachea or windpipe, carries air to and from the lungs. It is made of C-shaped rings of rigid cartilage (to prevent it from collapsing).

We have two bronchi. Each bronchus carries air between the trachea and a lung. The two bronchi subdivide many times to form tiny tubes called bronchioles. Bronchioles carry air to and from the air-sacs, or alveoli.

Each lung contains millions of tiny air-sacs called alveoli. The function of each alveolus is gas exchange: Oxygen passes from the air in the alveolus into the blood vessels. At the same time carbon dioxide and water pass from the blood vessels into each alveolus. The gases pass in each direction by a process called diffusion. As an adaptation for diffusion each alveolus has a very thin lining, is moist and is surrounded by many tiny blood vessels called capillaries. For more on diffusion see chapter 13 in Chemical World.

Is a sheet of muscle that forms the base of the chest. Along with the ribs and intercostal muscles (located between the ribs) the diaphragm causes air to move into or out of the lungs.