7) Exchange and Transport Flashcards
Why do multicellular organisms need an exchange surface
Diffusion is too slow
Long diffusion distance
small SA:Vol
High metabolic rate
What are the asaptations of the root hair cell
Long hairs - large surface area , inc rate of absorbtion
What are the adaptations of the Alveoli
Single layer of epithelium cells - short diffusion distance
Inc rate of diffusion
Good blood suply / ventilation - each alveoli has own capillary netwark , air is constantly replace , maintain o2 and co2 gradients
What are the structures of the gaseous exchange system in animalsand its functions
Goblet cells - Secrete mucus , trap microorganisms , prevent reach alveoli
Cilia - Beat mucus , waft mucus away towards throat
Elastic fibres - Help process of breathing out , elastic and stretchy , allow recoil
Smooth muscle - Control diameter of trachea,bronchi , bronchioles . control resistance to airflow moving in and out
Rings of cartliage - Provide support in trachea and bronchi, strong flexible , prevent collapsing
Explain inspiration in mammals
Externnal intercostal + diaphram contract
Ribcage move up and out
Diaphram flatten , inc volume of thorax
Kung pressure decrease
Sir flows in
Active process - require energy
Describe expiration in mammals
External intercostal + diaphram relax
Ribcage move down and inwards
Thorax volume decrease , air pressure increase
Air forced out
passive process
Define :
Tidal volume
vital capacity
Breathing rate
Oxygen uptake
Volume of air in each breath
The maximum volume of air that can be breathed in or out
How many breaths are taken per minute
Rate of o2 uptake per minute
Describe how a spirometer investigaate breathing
oxygen-filled chamber with a movable lid
Breathe tube , chamber moves up and down .
Recorded by a pen and writes on a rotating drum , creating spirometer trace.
Soda lime absorb carbon dioxide
How do fill gills allow ventilation
Fish open mouth , lowers floor of buccal cavity
Volume of buccal cavity increase , pressure decreases.
Water enters .
FMouth close , floor of buccal cavity raises , volume decreases,pressure increases
Water pass over gill filamets over operculum
Pressure force operculum to open , water leave gills
How does fish counter-current system maximise gas exchange
Thin gill filaments and lamellae - big surface area.
Gill filaments covered with gill plates -inc surface area further.
Blood and water flow in opposite gradient , water conc is always higher , maximise o2 uptake and maintain steep conc gradient
How do exchange gases occur in insects
Pipe called tracheae.
Air move in through spiracles.
Tracheae branch into smaller tracheoles - thin and permeable walls
Oxygen diffuse into fluis into body cells.
Use abdominal movements to change volume as air move in and out , wing movement allow pump in thoraxes
