Biology

• Cell respiration
• Gas exchange

• Breakdown of foos (glucose and lipid) to release energy
• Make ATP
• Rest of the energy is released as heat

Involoves uptake of oxygen and release of carbon dioxide

• Relatively large organisms with a large volume of living cells
• Maintain a high body temperature
• High metabolic rates

• Large surface area to volume ration
• Thin
• Permeable to gases
• Ventilation to maintain a conc. gradient
• Movement of internal medium (blood) to maintain a conc. gradient

• Flexible airway that is supported by rings of cartilage to prevent it from collapsing as the air pressure falls.
• Made up of cilated epithelim and goblet cells which produces mucus

• Bronchi are two divisions of the trachea each leading to a lung. The bronchioloes are more branches off of the bronchi.
• They both produce mucus to trap dirt

• Minute air sacs that contain collagen and elastic fibres and are lined with epithelium.
• The elastic fibres allow them to stretch when filled with air and spring back when breathing out
• Alveolar membrance is the gas-exchange surface

• Nose
• Trachea
• Bronchi
• Bronchioles
• Alveoli

Detergent like substance which reduces its surface tension so prevents the alveolar walls bing pulled together and collapsing

The pressure that a gas exerts when in a mixture of gases

The volume of air remaining in the lungs after a maximum expiration

The space in the trachea, bronchi, and other air passages which contains air that does not reach the alveoli during respiration

• Some blood entering the lings doesn't go into the alveolar capillaries and therefore stays deoxygenated
• Some alveoli and under-ventialted

• External IMs contract, internal IMs relax
• Ribs pulled upwards and outwards, increasing the volume of the thorax
• Diaphragm contracts causing it to flatten, increasing volume, which drops pressure
• Air moves from high pressure to low so moves into the lungs

• Internal IMs contract so external IMs relax
• Ribs move down and in, decreasing volume
• Diaphragm relaxs returning to dome shape which decreases volume and increase pressure
• Pulmonary pressure is greater than atmosphere so air moves out

• Increased breathing rate
• Increased depth of breath
• Increased oxygen consumption
• Increase in carbon dioxide in expired air

• An expansion of alveoli
• Diaphragm and intercostal muscles become larger
• Number of capillaries in the lungs increases

Voulme breathed in and out in one cycle

Pulmonary ventilation (cm³min^-1) = tidal volume (cm³) x breathing rate (min^-1)

To replace old air and to allow cell respiration to take place

• Surface area x concentration difference
•         Length of diffusion path

Squamous

Destroy bacteria and viruses

Cushions movement of the lungs