Gas Exchange (Core)Stephen Taylor

i-Biologynet

Assessment Statements Obj

641 Distinguish between ventilation respiration and gas exchange 2

642 Explain the need for a ventilation system 3

643 Describe the features of alveoli that adapt them to gas exchange 2

644 Draw and label a diagram of the ventilation system including trachea lungs bronchi bronchioles and alveoli 1

645Explain the mechanism of ventilation of the lungs in terms of volume and pressure changes caused by the internal and external intercostal muscles the diaphragm and abdominal muscles

3

Assessment statements from Online IB Biology Subject GuideCommand terms httpi-biologynetibdpbiocommand-terms

What connections can you make with other topics

Gas Exchange

MrT sayshellipI pity the fool

who thinks breathing is respiration

httpwwwlastfmmusicMrT+images27372765

Why do we need a ventilation system We are large organisms Oxygen cannot diffuse into all our cells directly from the air nor can waste products be directly ejected from the body We have specialised organ systems which are efficient but need delivery of nutrients and removal of waste The ventilation system ensures the blood can be the medium for this

We are land-borne Gases need moist surfaces (membranes) in order to diffuse Our lungs are moist membranes allowingoxygen to diffuse into the blood and carbon dioxide to diffuse out

The ventilation system maintains a large concentration gradient between the alveoli and the blood The constant flow of past the alveoli brings blood with a high CO2 concentration and low O2 concentration Breathing out keeps the CO2 concentration in the alveoli low so it diffuses out of the blood Breathing in keeps O2 concentration in the alveoli high so it diffuses into the blood

Diagram from httpwwwsciencequiznetjcsciencejcbiologygapfillingbreathingsystemhtm

httphigheredmcgraw-hillcomsites0072495855student_view0chapter25animation__gas_exchange_during_respirationhtml

httpwwwwisc-onlinecomobjectsViewObjectaspxID=AP15104

Which process(es) of membrane transport are being used in gas exchange at the membranes of the alveoli

httpwwwfootprints-sciencecoukalveolihtm

Breathing Exercises ndash desk yoga (itrsquos IBDP after all letrsquos bust some stress)

1 Simple exercises Keep your neck straight bull Rotate shoulders forwards then backwards 5 times each bull Bend your neck to touch your head to your shoulder left then right 5 times each bull Tilt your head forward touching chest then backward 5 times each

2 Breathing observationbull Close your eyes breathe normally bull ldquoObserverdquo the breathing process

3 Pranayamabull Stand up bull Take gentle deep breaths bull Feel the air moving in and out trying to control its flow bull Think happy thoughts about graduation

Breathing exercises from httpwwwhealthandyogacomhtmlnewsexercisehtmlImage 11750 Foot Yoga Moment httpwwwflickrcomphotos94833286N002838289483 Found on flickrccnet

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