You will observe:A mist will form on themirror. Touchthis mist, and
you will findmoistureon the tip ofyourfinger.
In additionto carbondioxide, watervapor is a waste productofthe
activitiescarried on in the cellsofyourbody. Asbloodflowsthroughthe
smallest type of blood vessels, the capillaries, it picks up wastevapor. The
bloodcarries thisvaporto the lungs to be exhaled, to the skin to be released
as an element ofperspiration,and to the kidneys to be released in the form
ofurine.
EXAMINING LUNG TISSUE FROM ABEEF OR CALF
Materials: Aparingknife, awide-mouthedjar,tap waterand acalfor
beef lung. Yourmother'sbutcherwill be able to supply you with the lung.
Follow this procedure:Fill thejarthree-quartersfulloftap water. Puta
pieceofanimallung tissue in the water.
You will observe:The piece of lung tissue will float in the water. Even if
you try to force it down, it will bob back up to the surface.The lung tissueofallmammalsis similar. The lungsofmammalscontain
tiny spaces calledair sacs. These spacesfunctionlike those in a sponge, for
they hold the airthatis inhaledand collect the airthatis going to be exhaled.USING ATHERMOMETER-NATURAL BODY HEAT
Materials:An oralthermometer,alcohol,absorbentcotton.
Follow this procedure: Shake the thermometer down below "normal."
Clean it withcottonsoakedin alcohol.