Respiratory System

• Bronchial tubes are airways that branch off from the trachea into the lungs.
• Alveoli are tiny sac-like structures at the end of bronchioles where gas exchange occurs between the bloodstream and alveolar air.
• The trachea is the windpipe, which connects the larynx to the bronchi.
• Alveolar ducts connect to clusters of alveoli.
• The respiratory system is responsible for breathing, which involves taking in oxygen (O2) through inhalation and expelling carbon dioxide (CO2) during exhalation.
• What happens during inspiration?

  1. External intercostal muscles contract while intercostal muscles relax
  2. The ribs are pulled up and outwards, increases the volume of the thorax
  3. The diaphragm muscles contract and flatten
  4. Increase in volume
  5. Decrease in pressure
• What occurs during expiration?

  1. External intercostals relax
  2. Ribs move downwards and inwards
  3. Decrease in volume
  4. Increase in pressure
• The nasal passage allows air to flow into the throat and then into the lugs. As it flows through, the air is warm and humidified
• What is the difference between oesophagus and trachea?

  Oesophagus connects back and mouth with lower point of pharynx

  Trachea moves towards the lungs
• What is the role of epiglottis?

  A flap of cartilage covered with a membrane. It will cover over the trachea when eating food.
• Label

  A) SURFACE AREA

  B) CONCENTRATION GRADIENT

  C) DIFFUSION DISTANCE

  
• Label

  A) Trachea

  B) Larynx

  C) Clavicle

  D) External intercostal muscles

  E) Internal intercostal muscles

  F) Sternum

  G) Diaphram

  H) Plueral cavity fluid

  I) Rings of cartillage

  J) Right lung

  K) Bronchus

  L) Bronchioles

  M) Ribs

  N) Intercostal muscles

  O) Plueral membranes

  
• Label

  A) Air in

  B) Blood low in CO2 HIGH IN 02

  C) Alveolus wall

  D) Capilliary wall

  E) Oxygen diffusing into the blood

  F) Oxygen moves around body by Red blood cells

  G) Blood low in 02 high in C02

  H) C02 diffusing into blood

  I) Red blood cells

  
• How is the alevoli adapted for rapid gas exchange?

  1. lots of alveoli per bronchiole
  2. Curved shape
  3. Concentration gradient moves high to low
  4. Increases surface area
• How is the concentration gradient maintained?

  1. Good blood supply
  2. Ventilation
• How does oxygen enter the red blood cells from the air inside the alveoli?

  oxygen will diffuse by simple diffusion through the alveoli membrane into the capillary membrane
• Walls of alveoli are thin which provided a short diffusion pathway
• Alveoli and capillaries provide a large surface area
• Describe and explain how lung are adapted to allow for rapid gas exchange

  The alveoli is 1 cell thick to help the gases move across the membrane

  This decreases the diffusion distance. Alveloi have a curved shape
• – lung cancer is more prevalent in older people and develops over decades