Parts of the respiratory system

• Trachea


  Carries air in and out of the lungs
• Bronchus


  Distributes air throughout the lungs until reaching the respiratory bronchioles
• Bronchioles


  Deliver air to a diffuse network of around 300 million alveoli in the lungs
• Ribs


  Aid respiration
• Lungs and respiratory system

  Allow us to breathe
• Diaphragm


  Muscle that helps you inhale and exhale (breathe in and out)
• Respiratory system


  Gas exchange - oxygen enters the blood and carbon dioxide is removed
• Breathing in


  1. Intercostal muscles contract raising the ribs up and out

  2. Diaphragm contracts and flattens

  3. Increase in volume of thoracic cavity

  4. Air moves in
• Breathing out


  1. Intercostal muscles relax so the ribs move down and in

  2. Diaphragm relaxes and moves back to its dome shape

  3. Decrease in volume of thoracic cavity

  4. Air moves out
• Gas exchange


  Oxygen is taken in from the air and carbon dioxide is released from the body
• Alveoli


  • Thin walls lined with a single layer of cells allowing efficient diffusion of gases
  • Surrounded by a dense network of capillaries ensuring a large surface area for gas exchange
  • Several million in both lungs giving a great surface area allowing carbon dioxide to go out and oxygen to go in
• The lungs are present in the thoracic cavity (everything enclosed by the ribcage)
• Breathing allows gases into and out of the respiratory system
• The function of the respiratory system is gas exchange - that is oxygen enters the blood and carbon dioxide is removed
• Gas exchange


  The process by which oxygen is taken in and carbon dioxide is released from the body
• Gas exchange in the human respiratory system

  1. Breathing in

  2. Air passage

  3. Alveoli

  4. Diffusion

  5. gas exchange

  6. Exhalation

  7. Gas transport

  8. Repeat process
• Breathing in


  1. Diaphragm contracts and moves downward

  2. Intercostal muscles between the ribs contract

  3. Ribcage expands

  4. Negative pressure in the chest cavity

  5. Air drawn into the lungs through the trachea
• Air passage


  1. Inhaled air travels through the trachea

  2. Trachea branches into two bronchi

  3. Bronchi divide into smaller bronchioles

  4. Bronchioles lead to alveoli
• Alveoli


  • Tiny air sacs where gas exchange takes place
  • Surrounded by a network of capillaries
• Diffusion


  1. Oxygen from inhaled air passes through alveoli walls into capillaries

  2. Oxygen binds to hemoglobin in red blood cells

  3. Oxygen transported to cells for cellular respiration
• Carbon dioxide exchange


  1. Carbon dioxide from cells diffuses from capillaries into alveoli

  2. Carbon dioxide exhaled out of the body
• Exhalation


  1. Diaphragm and intercostal muscles relax

  2. Chest cavity decreases in size

  3. Increased pressure in lungs

  4. Air pushed out of lungs through trachea
• Gas exchange

  1. Oxygen carried by red blood cells to tissues

  2. Carbon dioxide transported back to lungs in bloodstream
• The process of gas exchange continues with each breath, ensuring the body receives an adequate supply of oxygen and removes carbon dioxide waste
• Alveoli are tiny air sacs where gas exchange occurs between blood capillaries and air.
• Bronchioles are smaller tubes branching off from bronchi, which end at alveoli.
• The trachea is made up of cartilage rings that keep it open.
• Oxygen is released from red blood cells at the tissue level, while carbon dioxide enters them.
• Diaphragm contracts downwards during inhaling, increasing lung volume.
• Diaphragm is a dome-shaped muscle that separates thoracic and abdominal cavities, contracting during inspiration to increase lung volume.
• Lungs contain millions of alveoli, where gas exchange takes place.
• Intercostal muscles contract during inhaling, expanding ribcage and increasing lung volume.
• Intercostal muscles lie between ribs and expand/contract them during breathing.
• Haemoglobin has four binding sites for oxygen.
• label the parts of the respiratory system

  A) rib cage

  B) intercostal muscles

  C) lung

  D) diaphragm

  E) bronchus

  F) alveoli

  G) bronchioles

  H) trachea