gas exchange Flashcards
inludes gas exhange in plants,fish,humans and insects
what is ficks law
rod is proportional to sa x difference in conc /thickness of membrane.
describe the process of inspiration in humans
thoracic cavity enlarged creating an increased volume and rib cage moves up and out as intercostal muscles contract.
-diaphragm contracts and moves down
-pressure decreases and air moves down a pressure gradient.
what is the ventilation rate
amount of air breathed in and out in one min. =tidal volume x breathes/min
what is the tidal volume
how much air is inhaled and exhaled in each breath.
describe some adaptations of the alveoli in humans
arranged in grape like structures and have a lrg sa.
-1 cell thick of squamous epithelial cells.
-densely covered ion blood capillaries.
-inner walls lined with suffracant -lowers surface tension .
-alveoli moist to aid diffusion.
-contain stretch receptors which prevents alveoli overfilling with air.
how does protoctista exchange gases
absorbtion of oxygen across plasma mebrane and diffusion of c02 out fast enough to revent carbonic acid build up.
how does a flatworm exchange gases
have a large sa:v ratio so body surface used as respiratory surface
how does earthworms exchange gases
-cylinders so smaller sa-volume ratio.
-are slow moving for low metabolic rates.
-have a circulatory system to transport blood.-gases exchanged at surface and with cells by diffusion.
what do advanced eukaryotes need in order to have effective gas exchange
-ventillation for steep conc gradient.
-circulatory system.
-respiratory pigment -increase carrying capacity of oxygen
-a thin/permeable membrane.
-internal lungs.
describe the gill adapatations in fish
-many gill filaments to provide large surface area.
-large surface area mantained by density of water-prevents gills collapsing on each other.
-each filament has many lamellae.
-rich blood supply and ventilation of gills.
-one way current of water across surface area.
what form of gas exchange does cartilaginous fish take
parallel flow -have to keep swimming. Can only work until conc of o2 in gills is equal to conc in water
how do bony fish take in water
1.mouth opened-operculum closes.
-buccal cavity is lowered by contractions.
-volume inside buccal cavity increases and pressure decreases.
-water flows in down a pressure gradient.
what does the counter current system ensure
02 diffuses into blood along the whole length of the gill plate maintaining a constant diffusion gradient.
what are problems insects face
terrestrial so water could evaporate from surface -cuticle reduces this
-small sa-v ratio
-impermeable exoskeleton.
what are adaptations to an insects tracheal system
spiracle on body surface allowing air to enter.
-hairs help reduce water loss and prevents entry of solids.
-tracheae-chirin lined tubes that branch into non-chitin lined tracheoles straight to muscle.
-during flight movement of abdomen increases speed of air movement through spiracles.
