Exchange surfaces Flashcards
why do multicellular organisms need specialised surfaces
.diffusion distance is too far
.higher metabolic rates
.smaller SA:VOL ratio
features of specialised exchange surfaces
.large SA
.thin walls
.good blood ventilation
.surrounded by paritaly permeable membranes
ciliated epithelium tissue contains
goblet cells- produce and secrete mucus
.cilia on ciliated epithelial cells- waft mucus upwards to the mouth to be swallowed
trachea adaptations
.rings of cartilage to keep airways open
.smooth muscle to contract or relax to change airflow
.elastic tissue to allow stretching and recoiling
.lined with ciliated epithelial and goblet cells
bronchi adaptations
.reinforced with cartilage to keep airways open
.smooth muscle to contract or relax to change airflow
.elastic tissue to allow stretching and recoiling
.lined with ciliated epithelial and goblet cells
bronchioles adaptations
.not cartilage to change shape
.smooth muscle to contract or relax to change airflow
.elastic tissue to allow stretching and recoiling
.squamous epithelium cells
how do alveoli carry out gas exchange
.oxygen diffuses from alveoli into capillaries
.CO2 dissociated from haemoglobin into alveoli
adaptations of alveoli for gas exchange
.large SA
.partially permeable
.surrounded by capillaries
.ventilation of air
adapatations of capillaries for gas exchange
.thin walls
.red blood cells pressed against capillary walls
.large SA
.movement of blood
.slow movement of blood
what happens in inspiration
.external intercoastal muscles contract while internal intercostal muscles relax
.moving the ribcage up and out
.diaphragm contracts and flattens
.this increases the volume of the thorax
.the pressure inside is lower than outside the lungs so air flows in
what happens in expiration
.external intercostal muscle relax while the internal intercostal muscles contract
.moving the rib cage down and in
.diaphragm relaxes and flattens
.this decreases the thoraxs volume
.pressure inside the lungs is higher than the outside so air moves out
spirometer traces
breathing rate = num of breaths per min
.tidal volume = vol of air in or out per breath at rest
.vital capacity = maximum amount of air in or out
.residual volume = vol of air still remaining in lungs after largest expiration
how to calculate oxygen consumption
change in vol of gas/time
how to calculate ventilation rate
tidal volume(dm3) X breathing rate
why do insects need gas exchange
.they have high oxygen demands but their tough exoskeleton prevents direct gas exchange
structure of insect gas exchange
tracheae = air-filled tubes branching throughout the body
tracheoles = fine branches of tracheae that deliver gases to cells
spiracles = openings of the tracheal system on the exoskeleton
how does insect gas exchange work
.air enters the tracheal system through open spiracles
.air moves into tracheae and diffuses into tracheoles
.tracheoles transport the air directly into the cells
.oxygen diffuses in water in tracheal fluid and diffuses into body cells
.CO2 diffuses out into the tracheoles
.air is carried back to the spiracles and is released
why do bony fish need respiratory systems
.water has less oxygen than air
.they are very active
.water us denser than air = slower diffusion of oxygen
structure of gills
.gills are covered by operculum flap
.consist of stacked filament containing gill lamellae
.gill lamellae surrounded by blood vessels
adaptations of gills
.lamellae give large SA
.lamellae have thin membranes
.gills have rich blood supply
.countercurrent flow of blood
.overlapping filament tips slows water down to have more time for gas exchange
how does the countercurrent flow system work
.blood and water flow over lamellae at opposite directions
.oxygen-rich blood meets oxygen rich air and vise versa
.always a steep concentration gradient
how does fish gas exchange system work
.fish open mouth, increasing vol of buccal cavity and decreasing pressure
.this pulls the water into the buccal cavity
.water flows over gills
.water flows out through the operculum
