Naha ehitus

naha paksus varieerub 0,1 4 millimeetrini Ehituselt jaotatakse nahk kolme ossa: 1.pealisnahk ehk epidermis 2.prisnahk ehk dermis 2mm 3.nahaalune rasvkude

Nahk kaitseb kudesid ja organeid mehhaaniliste faktorite (lgid, hrumised, rhumised) eest tnu prisnahas olevatele kollageensetele ja elastsetele kiududele ning nahaalusele rasvkoele (http://www.vita.ee/dyna/site/130est.html)

Vananedes tekib kollageenimolekulide vahel jrjest uusi piksidemeid, mistttu naha elastsus ja painduvus vheneb. Kollageen on oma ehituselt spetsiaalne sidekoeline valk, mis moodustab 7080 % dermise kuivkaalust ning vastutab naha venivuse eest Elastiinkiud moodustavad dermise kuivkaalust 2% ja aitavad vljaveninud nahal oma esialgset kuju ja vormi saavutada.

NAHA PAKSUS ~4mm NAHA TIHEDUS 1g/cm- (on veest(1000 kg/m= 1 g/cm3)kergem) (0,001g/cm3)?? Alternatiiv nahad testimiseks- Kitse nahk, Sea nahk muscular tissue has a density of 1.06 g/ml Verevalum- Kapilaarid naha all purunuevad ning veri tuseb naha alla Naha alusekoe alternatiiiv-elatiin(standartootes0,04g/cm3 , plastiliin1.85g/cm) (naha tiheduse teema) Ainete lahustumisel ja erinevate koguste muutmisel vib saada ktte "naha(prisnaha=DERMISE=[2mm])" tiheduse!!!

ehk siis tihedus= mass/ruumalaga TIHEDUS roo (tihedus)p=mass/ruumala (ruumala)V=m/p (mass)m=p*V

Ruumalahikud (Toiduelatiin 40g elatiin 1 liiter vedelikku=0,04g/cm3)--->0,04g/cm3 VAJALIK:0,001g/cm3

Ruumala mtmisel on meil phihik kuupmeeter, this m3. Mahu mtmisel kasutatakse sageli ka mthikut liiter, this l. 1 liiter = 1 kuupdetsimeeter. 1l=1000ml Seos phihikuga m3 kuupmillimeeter mm3 1 m3 = 1 000 000 000 mm3 kuupsentimeeter cm3 1 m3 = 1 000 000 cm3 kuupdetsimeeter dm3 1 m3 = 1000 dm3 kuupmeeter m3 1m3 = 1 m3 Kuupkilomeeter km3 1 km3 = 1 000 000 000 m3 1 m3 = 1000 dm3 1 dm3 = 1000 cm3 1 cm3 = 1000 mm3

(PLASTILIIN TIHEDUSE ARVUTAMINE) How would you find the density of plasticine? Answer:

Roll the plasticine into a sphere and measure the diameter and use the formula for the volume of a sphere V=pi r^2, then weight the sphere to get the mass and use Density = Volume upon Mass. Alternatively, use Archimedes' principle: 1) Weigh a piece of plasticine to get its mass. Very carefully fill a glass with water so full that it cannot contain one more drop of water. Immerse the plasticine in the glass, collecting the water that has run out of the full glass. The volume of the water is equal to the volume of the plasticine. Determine the volume of the water by either weighing it (density of pure water is 1 g per mL) or by accurately measuring the volume. Density = mass (g)/ volume (mL) 2) If you have a balance that can determine mass of an hanging object, first weigh your plasticine to determine its mass. Then attach it to string and take its mass hanging (the string also has mass). Then take its mass while the plasticine is just submersed in water. It will weigh less when submersed in water. The loss of mass when submersed is equal to the mass of water that has the same volume as the plasticine. (density of water is 1 g per mL) Now you can determine the volume of the plasticine since the mass lost in g equals the volume of water in mL. Density is the original mass divided by the volume.