Respiratory System

• Upper Respiratory Tract:

  • Contains cilia and mucus to trap and sweep dust/microbes into the throat.
  • Nasal + oral cavity, Pharynx, Larynx, Trachea
• Lower Respiratory Tract:

  • Lungs
  • Bronchi Branches -> Bronchioles -> Aveoli
• Nose:

  • Allows air to enter the body
  • Filters, warms, and moistens air
  • Sense of smell
• Pharynx:

  • Connects the oral/nasal cavity to the trachea and esophagus.
• Larynx:

  • Prevents food from entering trachea (w/ epiglottis)
  • Vocal cord - speech
• Trachea:

  • Stays open for air to flow
  • Stiff C-shaped cartilage
• Lungs:

  • Remove waste products (CO2, Water Vapor) from blood
  • Oxygenate blood
• Bronchi:

  • Large airways that branch off the trachea
• Bronchioles:

  • Smaller airways that branch off the bronchi.
• Alevoli:

  • Exchange gas with pulmonary capillaries.
• Diaphragm:

  • Separates the thoracic and abdominal cavities.
  • Affects pressure, causing breathing.
• Inhalation

  • Diaphragm contracts, moving down
  • Intercostals contract, moving the ribcage out
  • Higher volume -> lower pressure
  • Air goes into the lungs
• Exhalation

  • Diaphragm relax, moving up
  • Intercostals relax, moving the ribcage in
  • Lower volume -> higher pressure
  • Air goes out the lungs
• Interpleural fluid allows for the movement of the lungs during inspiration and expiration
• Breathing Feedback Mechanism

  • Blood ~7.4 pH
  • CO2 (plasma) + water -> carbonic acid, pH drops
  • Chemoreceptors in blood vessels
  • Control Center: Medulla Oblongata
  • Diaphragm contracts faster to remove CO2 and increase pH
• External Respiration:

  The exchange of gases between the atmosphere and blood in the lungs.
• Oxygen and carbon dioxide diffuse across alveoli in the lungs into pulmonary capillaries.
• Internal Respiration:

  The exchange of gas between the body's cells and blood.
• Because of the concentration and pressure difference, CO2 in the cell and O2 bound to hemoglobin in blood diffuse.
• Cellular Respiration:

  The production of ATP for energy in the cell using oxygen and the breakdown of organic molecules (e.g: glucose)
• The mitochondria uses oxygen and the breakdown of glucose to produce ATP.
• The medulla oblongata controls breathing and heart rate.
• Systole is the heart at work.
• Diastoly is the heart at rest.
• Alveoli facilitate diffusion of O2 b/c

  • Thin
  • Moist
  • Numerous
• Protecting membrane around lungs

  • Pleura