mammalian gas exchange system

• Describe how alveoli are adapted to be useful exchange surfaces

  • Large number/a lot of alveoli create a large surface area which maximises the rate of diffusion
  • One cell thick- short diffusion path
  • Epithelium provides short diffusion distance
  • Elastic recoil helps with ventilation
  • Secrete surfactant which helps maintain surface area
  • Small size of the alveoli helps to provide a large surface area to volume ratio
• What tissue contains goblet cells?

  Ciliated epithelium
• What is the function of the smooth muscle?

  • Contracts/constricts, controlling lumen size
  • Smooth so blood flows easily over it
• What components of the gaseous exchange system contain cartilage?

  Trachea and bronchi
• What components of the gaseous exchange system contain smooth muscle?

  Trachea, bronchi, bronchioles
• What components of the gaseous exchange system contain elastic fibres?

  Trachea, bronchi, bronchioles, alveoli
• role of cartilage?

  • Strong
  • prevents collapse of trachea as pressure drops when you breathe in
• Role of elastic fibres?

  • stretched when you breath in
  • Recoil to help push air out during exhalation
• What components of the gaseous exchange system contain ciliated epithelium?

  Trachea, bronchi, bronchiole
• What cells are found in the epithelium?

  • Ciliated
  • Goblet
• why do mammals need a gas exchange system?

  • small SA:V ratio
  • high metabolic rate

  similar reasons to transport systems
• what are the four main aspects of a good exchange surface?

  • increased SA
  • thin layers
  • good blood supply- steep conc grad
  • ventilation to maintain diffusion gradient- for gases
• what do the lungs look like?

  organ which supports the gas exchange system

  A) pleural membrane

  B) ribs

  C) diaphragm

  D) bronchioles

  E) trachea

  F) deoxygenated

  G) oxygenated

  
• what purpose do moist surfaces provide in the gas exchange system?

  reduce evaporation from exchange surfaces- make air more humid
• what does the lining of trachea, bronchi and bronchioles look like?

  • ciliated epithelium- cilia waft mucous away from the lungs as it traps dirt and microorgies, can be wafted to back of throat and swallowed
  • goblet cells- secrete mucous
  • mucous

  
• what are the three main features of components in the gas exchange system?

  • elastic fibres
  • smooth muscle
  • cartilage