Lung Structure and Function
Cellular respiration
The process that takes place within cells
Within the mitochondria
To produce energy in the form of ATP.
This is done by:
o Glycolysis (cytoplasm)
o the Krebs cycle (mitochondrial matrix)
o and oxidative phosphorylation (mitochondrial inner membrane)
Oxidative phosphorylation requires protons, electrons and oxygen to produce water.
Breathing Respiration
O2 to CO2
O2 is used in cellular respiration and CO2 is taken from cellular respiration.
The circulatory system links both.
CO2 is toxic to the body.
Too much and this can affect breathing, neurones and the brain.
Airway structure
, Conducting airways: conduct air in and out of the lungs (air-related).
o Consists of the nose, mouth, pharynx, and larynx.
o Where no gas exchange occurs.
o So, also includes bronchi, bronchioles, and trachea.
o It has cartilage so the airways won’t collapse.
Respiratory airways: regions where gas exchange occurs (exchange related).
o It primarily consists of the alveoli and alveolar ducts.
o Contains pores to allow the movement of gases.
o Large SA
Ventilation
Inspiration: pressure in the alveoli drops
By increasing the dimensions of the lungs.
A decrease in pressure leads to oxygen moving in.
Structures to change lung volume
The lungs are passive elastic structures.
No muscles of their own so, they cannot inflate on their own.
Surrounded by pleural sacs with pleural fluid.
Pleural sack has two layers:
Visceral pleura: adheres to the surface of the lungs. Secretes pleural fluid acting as a
lubricant allowing the lungs to move smoothly. Connective tissue to allow elasticity
and strength with elastin and collagen.
Parietal Pleura: an outer layer that lines the chest wall (intercostal muscles, ribs and
spinal column) and diaphragm.
Cellular respiration
The process that takes place within cells
Within the mitochondria
To produce energy in the form of ATP.
This is done by:
o Glycolysis (cytoplasm)
o the Krebs cycle (mitochondrial matrix)
o and oxidative phosphorylation (mitochondrial inner membrane)
Oxidative phosphorylation requires protons, electrons and oxygen to produce water.
Breathing Respiration
O2 to CO2
O2 is used in cellular respiration and CO2 is taken from cellular respiration.
The circulatory system links both.
CO2 is toxic to the body.
Too much and this can affect breathing, neurones and the brain.
Airway structure
, Conducting airways: conduct air in and out of the lungs (air-related).
o Consists of the nose, mouth, pharynx, and larynx.
o Where no gas exchange occurs.
o So, also includes bronchi, bronchioles, and trachea.
o It has cartilage so the airways won’t collapse.
Respiratory airways: regions where gas exchange occurs (exchange related).
o It primarily consists of the alveoli and alveolar ducts.
o Contains pores to allow the movement of gases.
o Large SA
Ventilation
Inspiration: pressure in the alveoli drops
By increasing the dimensions of the lungs.
A decrease in pressure leads to oxygen moving in.
Structures to change lung volume
The lungs are passive elastic structures.
No muscles of their own so, they cannot inflate on their own.
Surrounded by pleural sacs with pleural fluid.
Pleural sack has two layers:
Visceral pleura: adheres to the surface of the lungs. Secretes pleural fluid acting as a
lubricant allowing the lungs to move smoothly. Connective tissue to allow elasticity
and strength with elastin and collagen.
Parietal Pleura: an outer layer that lines the chest wall (intercostal muscles, ribs and
spinal column) and diaphragm.
