temp 3

Cards (165)

  • What arises the need for specialised exchange surfaces?
    Increased size and surface area to volume ratio
  • Why can single-celled organisms easily exchange substances?
    They have a short distance to cross
  • What do multicellular organisms require for efficient gas exchange?
    Specialised exchange surfaces
  • What are features of an efficient exchange surface?
    Large surface area and thin structure
  • Why is a good blood supply important for exchange surfaces?
    It maintains a steep concentration gradient
  • How many pairs of gills do bony fish have?
    Four pairs
  • What is the function of lamellae in fish gills?
    They participate in gas exchange
  • How does blood and water flow across the lamellae?
    In a counter current direction
  • Why can't fish survive long out of water?
    Gills stick together without water
  • What initiates ventilation in fish?
    Opening the mouth and lowering the buccal cavity
  • What role does the operculum play in fish ventilation?
    Acts as a valve and pump
  • How do insects transport oxygen to tissues?
    Through spiracles and tracheae
  • What are spiracles in insects?
    Small openings for gas exchange
  • How do gases move in and out of insect tracheoles?
    Through diffusion and mass transport
  • What adaptations do plant leaves have for gas exchange?
    Stomata and air spaces
  • What is the function of stomata in leaves?
    Allow gases to enter and exit
  • What is the structure of the lungs in mammals?
    A pair of lobed structures
  • What protects the lungs in the chest cavity?
    The rib cage
  • What prevents friction between the rib cage and lungs?
    A lubricating substance
  • What muscles are involved in ventilation?
    Intercostal muscles and diaphragm
  • How does air enter the lungs?
    Through the trachea, bronchi, and bronchioles
  • Where does gaseous exchange occur in mammals?
    In the walls of alveoli
  • What keeps the airways open?
    Rings of cartilage
  • How do trachea and bronchi differ?
    Bronchi are narrower than trachea
  • What is the composition of the airway walls?
    Cartilage, smooth muscle, and elastic fibres
  • What type of epithelium is found in the airways?
    Ciliated epithelium
  • What is the role of goblet cells in the airways?
    Secrete mucus to trap bacteria
  • How do smooth muscles affect airflow?
    They control the diameter of the airway
  • What do elastic fibres do during breathing?
    Stretch when exhaling and recoil when inhaling
  • What is ventilation composed of?
    Inspiration and expiration
  • What happens during inspiration?
    Volume in thorax increases, pressure decreases
  • What occurs during expiration?
    Volume in thorax decreases, pressure increases
  • What is a spirometer used for?
    Measuring lung volume
  • What is vital capacity?
    Maximum volume of air in a breath
  • What is tidal volume?
    Volume of air breathed at rest
  • How is breathing rate calculated?
    By counting peaks in spirometer trace
  • What is residual volume?
    Air always present in the lungs
  • What is inspiratory reserve volume?
    Additional air breathed in during exercise
  • What is expiratory reserve volume?
    Additional air exhaled beyond tidal volume
  • What is digestion?
    Hydrolysis of large molecules into smaller ones