Lungs and Health Studies

• Ventilation is the sequence of breathing movements that moves gases to and from the internal gas exchange surface.
• The five properties of a gas exchange surface are having a large surface area, thin, maintains concentration gradient, moist and is permeabl.
• Fick’s Law is that the

  Rate of diffusion =(surface area x difference in concentration) /Diffusion distance
• The trachea is a tube like structure that carries air from the mouth to the lungs. It is kept open with cartilage rings.
• Bronchi are the two parts of the trachea when it splits as it enters the lungs.
• Bronchioles are the smaller division of bronchi into smaller parts. The Bronchioles supply the alveoli with air.
• Alveoli are small sacks at the end of bronchioles that act as the interface between the air in the lungs and the blood.
• Deoxygenated blood is brought to the lungs by the pulmonary artery from the heart and returns when oxygenated via the pulmonary vein.
• to get oxygen into the blood stream the oxygen has to diffuse from the alveolar air space through the alveolar epithelium (made of squamous cells) and through the capillary endothelium into the blood.
• The alveoli epithelium is made out of squamous cells
• Squamous cells are squashed cells (that reduce the diffusion distance.
• Inhalation (active) causes External intercostal muscles to contract, the diaphragm contracts and flattens, Thoracic cavity volume increases, thoracic pressure decreases and the air moves into the lungs down the pressure gradient.
• Exhalation (passive) causes External intercostal muscles to relax, Diaphragm relaxes and domes up, thoracic cavity volume decreases, pressure in thoracic increases and air moves out of the lungs down the pressure gradient.
• Internal Intercostal muscles only contract during forced exhalation.
• A constant blood flow keeps a high concentration gradient in capillaries.
• Pulmonary ventilation is the volume of air exchanged in one breathing cycle.
• Pulmonary ventilation = ventilation rate x tidal volume
• Tidal volume is the natural breathing volume
• Inspiratory/ Expiratory reserve is the extra volume required for a deep breath.
• Residual Volume is the air that remains in the lungs to prevent the collapse of the alveoli
• Vital capacity is the maximum volume of air a person can expel from the lungs.
• A risk factor is something that increases your chance of developing a disease.
• Percentage change = (change/original) x 100
• Casual link is a change in one variable that results from or is caused by a change in another variable.
• A Correlation shows that there is a relationship between the two variables (might not be a casual one)
• Correlation does not show cause and effect.
• The word equation for aerobic respiration is oxygen + glucose = carbon dioxide + water
• Diffusion is the movement of particles from a high concentration to a low concentration.
• The factors of diffusion are temperature,concentration gradient, surface area and thickness (of the diffusion surface)
• Alveoli are air sacs
• aerobic respiration takes place in the mitochondria.
• The symbol equation for areobic respiration is

  C6H12O6 + 6O2 = 6CO2 + 6H2O