Respiratory System

• System responsible for bringing oxygen into the body and removing carbon dioxide

  • Nasal Cavity
  • Pharynx (throat)
  • Larynx
  • Trachea
  • Epiglottis
  • Bronchi (Bronchial Tubes)
  • Bronchiole
  • Alveoli
  • Lungs
  • Pleural membranes
  • Diaphragm
• Nasal Cavity


  Nose, filters, warms and moistens incoming air entering the body before it reaches the lungs
• Pharynx (throat)


  Connects oral and nasal cavities to larynx and esophagus, path for air and food
• Larynx


  Contains vocal cords, made of cartilage, Adam's apple
• Trachea


  Windpipe, where air passes from pharynx to lung
• Epiglottis


  Flap that covers the opening of the trachea when swallowing, closes off access to trachea when swallowing food (esophagus left open)
• Bronchi (Bronchial Tubes)


  Two tubes that carry air from trachea to the lungs
• Bronchiole


  Branch off the bronchi, found inside the lung, carries air to alveoli
• Alveoli


  Air sacs in your lungs, site of gas exchange with the capillaries
• Lungs


  Two soft, spongy organs, right lung = three lobes, left lung = two lobes
• Pleural membranes


  Surrounds the lung and lines the inner wall of the chest cavity
• Diaphragm


  Large, thin band of muscle, separates the chest cavity from the abdominal cavity
• Parietal


  Outer layer of pleural cavity
• Visceral


  Inner layer of visceral cavity
• How we breathe


  1. Inspiration: inhaling - air moves into the lungs

  2. Expiration: exhaling - air is forced out of lungs
• Inhaling


  1. Diaphragm contracts and moves downward

  2. Rib muscles contract, rib cage moves up and out

  3. Volume of chest cavity increases

  4. Lowers air pressure in the chest

  5. Air moves down trachea into lungs filling extra space
• Exhaling


  1. Diaphragm relaxes and moves upward

  2. Rib cages relaxes, moves inward and down

  3. Volume of chest cavity decreases

  4. Increases air pressure in chest

  5. Air moves out of lungs
• External Respiration


  The exchange of oxygen and carbon dioxide in the lungs
• Internal Respiration


  The exchange of oxygen and carbon dioxide between the tissue cells and the blood
• External respiration


  1. Gas exchange in the lungs

  2. The movement of oxygen gas and carbon dioxide gas in opposite directions between the alveoli and blood capillaries

  3. After inhalation of oxygen, the concentration of oxygen gas is higher in the alveoli than in the capillaries, allowing for the diffusion of oxygen into the blood from the alveoli to the capillaries

  4. After cellular respiration (cells use oxygen and produce carbon dioxide), the concentration of carbon dioxide gas is higher in the capillaries than the alveoli, therefore, carbon dioxide diffuses out of the blood capillaries into the alveoli

  5. Carbon dioxide is then exhaled
• Circulation


  • Refers to dissolved oxygen and carbon dioxide being carried by the blood (circulatory system) to and from the body cells
  • Red blood cells contain hemoglobin
  • Oxygen binds to hemoglobin and is transported by the red blood cells to the body cells
• Internal respiration


  1. Gas Exchange in the Tissues

  2. As the heart pumps the oxygenated blood to the tissues, oxygen diffuses from red blood cells to tissues

  3. Carbon dioxide diffuses from tissues and attaches to hemoglobin on red blood cells

  4. Deoxygenated blood travels back to the heart, and then to the lungs again for gas exchange
• Sickle-Cell Anaemia


  • A mutated form of hemoglobin distorts the red blood cells into a crescent shape
  • Normal red blood cells move easily through blood vessels to carry oxygen to all parts of the body
  • Sickle-shaped cells are stiff and sticky and tend to form clumps and get stuck in blood vessels
  • The clumps of sickle cell block blood flow in the blood vessels that lead to the limbs and organs
  • Blocked blood vessel can cause pain, serious infection, and organ damage