Respiration in humans

• Glucose in food is broken down mostly in the presence of oxygen. This process releases energy
• Aerobic respiration involves the breakdown of glucose in the presence of oxygen produces carbon dioxide and water as waste products, generates large amount of energy
• Word equation for aerobic respiration is glucose+oxygen—>carbon dioxide + water
• Anaerobic respiration is the breakdown of glucose in the absence of oxygen generates relatively small amount of energy
• Word equation for anaerobic respiration is glucose -> lactic acid
• Why is Anaerobic respiration important?

  during vigorous physical activity, aerobic respiration alone is not enough to provide the increased energy demand, hence anaerobic respiration occurs in muscle cells to meet this increased energy demand to keep the muscles contracting
• Respiration refers to the breakdown of glucose to release energy which occurs at cellular levels. Breathing, in the other hand involves inhalation and exhalation
• What happens during vigorous activity?

  muscle cells need more energy to contract, increased heartrate to Supply oxygen increased breathing to obtain oxygen
• Insufficient supply of oxygen in the muscles would lead to build up of latic acid through anaerobic respiration, muscles will then incur oxygen debt
• Oxygen debt is the amount of oxygen needed to remove lactic acid
• Continued fast heart rate?

  to transport lactic acid back to the liver via blood for removal and to transport oxygen to liver
• Continued deeper and faster breathing?

  obtain oxygen for supply to liver
• On the inner walls of trachea and bronchi are gland cells and epithelial cells

  gland cells secret mucus that traps dust particles Les and bacteria in the air that is channelled to the lungs

  epithelial cells have cilia that sweep trapped particles Les and bacteria yo the bronchi and trachea to the pharynx
• One cell thick alveoli walls ensuring faster rate of diffusion along with numerous alveoli to increase surface area for gaseous exchange
• cigerrate smoking can cause

  chronic bronchitis

  means inflamed airways excessive mucus secretion causing the cilia linings to be paralysed. Can lead to blocked airways
• Effects of tobacco

  Emphysema

  partition walls between alveoli break down due to violent coughs reducing surface area of gaseous exchange the lungs lose their elasticity and become inflated with air

  symptoms wheezing