NUTRITION AND HEALTH
Likeall living things, wehavethreelifeprocesses: interaction, nutrition and reporduction. We use differentbodysystemsfornutrition. In thisunityouwilllearnhowbodysystemsworktogethertoprovidethenutrients and theoxygenourbodyneeds.
1-NUTRITION
Itistheprocess of takingin food and turningitintoenergy. Foodcontainsthenutrientsweneedtolive and grow. Whenweeat, wetakethesenutrientsintoourbody and transformthemintomaterial thathelpsusgrow, repairsdamagedcells and givesusenergy.
2-DIGESTIVE SYSTEM
Ourdigestivesystembreaksfooddownintosmallsubstancescallednutrients. Allourorgans and musclesneedthesenutrients. Once thedigestivesystem has extractedthenutrients, itgetsrid of waste.
2.1.ORGANS OF OUR DIGESTIVE SYSTEM
Thedigestivesystemismade up of sixorgans, they are the:
1. Mouth: foodentersourbodythroughourmouth.Herefoodisbroken up bytheteeth and mixedwithsalivabythetongue.
2. Oesophagus: a longtubebetweenourmouth and thestomach.Foodgoesdownthistubeintothestomach.
3. Stomach: itislike a bag and it secretes gastricjuice, thestomachreceivesfoodfromtheoesophagus and mixes itwiththisgastricjuice.
4. Intestine: a longtube. Itiscomposed of twoparts:
- Small intestine: itisaboutseven metres long. There are lots of bloodvessels. Nutrientspassintothebloodhere.
- Largeintestine: itisaboutone metre and a halflong. Ittakesthebadsubstancesfromourbody. Watergoesoutintothebody and thewastebecomesharder.
5. Anus: itis at theend of thelargeintestine. Faeces are eliminatedthroughtheanus.
3-THE EXCRETORY SYSTEM
Excretorysystemhelpsourbodytogetrid of excesswater and wasteproducts. Wecleanourblood and eliminatewastefromourbody.
3.1. ORGANS OF THE EXCRETORY SYSTEM
1. Kidneys: whenthebloodgoesthroughhere, excesswater and wasteproducts are dicreased and trasnsformedintourine.Theurinegoesintothebladder.
2. Ureters: theurinegoesdownthesetubestothebladder.
3. Bladder: theurineisstored in this bag. Whenitisfullitsends a messagetothebrain.
4. Urethra: theurineleavesthebodythroughthistube.
4-THE CIRCULATORY SYSTEM
Circulatorysystemworksallthe time, day and night. Itis a transportsystemthattakesbloodtotheparts of thebody. Bloodis a veryimportant red liquid in ourbody. Itcarriesoxygen and nutrientstodifferentparts of thebody. Bloodgoesaroundthebody: circulation. Themainorgan of thissystemis
1. Heart: aninvoluntarymuscle. Itis a hollowmusclethatpumpsbloodaroundourbody.Itisbetweenourtwolungs.
Bloodcirculatesaroundourbodyinside
2. Bloodvessels: a networkthattakesthebloodaroundthebody: Therethreetypes:
a) Arteries: takethebloodfromourhearttotherest of thebody.
b) Veins: returntheblood back toourheart.
c) Capillaries: connecttheveins and arteries.
Bloodhas a wateryliquidcalledplasma. The plasma carriesnutrients and alsored cells,whitecells and platelets.
5-RESPIRATORY SYSTEM
Allourorgans and musclesneedoxygentofunction. Bloodpicks up theoxygenourbodyneedsfromthe air intothelungs. whenwebreathe, therespiratorysystemtakesoxygen and eliminatescarbondioxide.
5.1. ORGANS OF RESPIRATORY SYSTEM
1. Nose: has twonostrilswithlittlehairsto stop foreignobjects. They are narrow at the back.
2. Windpipe: divides intotwotubesthatgointothelungs.Thetubes are calledthebronchi.
3. Lungs: are liketwobigsacks. They are like a sponge. They are made up of lots of little bags calledalveoli. The air goesintothealveoli.
6-HEALTH AND NUTRITION
We are whatweeat. Ourdietsneedtobehealthy and balanced. Itisnecessarytoeat a variety of foodwithdifferentnutrients: mineralsand vitamins(vegetables and fruit), carbohydrates (giveenergy), proteins (helpusgrow and havestrongbones and teeth)and fats(extra energyforwhenweneedit). Avoideatingsalty and sugaryfoods.drinklots of water.
Tohave a healthylifestyle:
a) Be active: do exercice at leastthree times a week.
b) Sleep: sleep at leastninehours a night.
c) Limitscreen time: try nottospend more thantwohours a day.
d) Protectyourbodyfrom bacteria and virusesby:
-washingyourhands and brushyourteeth.