Download - form 4 biology chap6 pt3
LEARNING LEARNING OUTCOMESOUTCOMES
To explain what malnutrition isTo explain what malnutrition is To explain the effects of malnutrition To explain the effects of malnutrition
using examplesusing examples To describe ways to reduce the chance To describe ways to reduce the chance
of contracting certain health problems of contracting certain health problems due to one’s dietdue to one’s diet
To describe ways to reduce the effects To describe ways to reduce the effects of certain health problemof certain health problem
Malnutrition and Its Malnutrition and Its EffectsEffects
Malnutrition Malnutrition : lack of one or more of : lack of one or more of the nutrients required in the diet to the nutrients required in the diet to maintain good healthmaintain good health
Can be caused by :Can be caused by : A reduced intake of nutrients A reduced intake of nutrients
(undernourishment)(undernourishment) An inability to use absorbed nutrientsAn inability to use absorbed nutrients The failure to meet a required increase The failure to meet a required increase
in nutrient intakein nutrient intake Nutrient losesNutrient loses
Malnutrition & Its Malnutrition & Its EffectsEffects
3 stages to provide energy in cases of 3 stages to provide energy in cases of malnutrition :malnutrition :
The carbohydrate stores in the body are The carbohydrate stores in the body are used upused up
The fat reserves are oxidisedThe fat reserves are oxidised Proteins are broken down. When protein Proteins are broken down. When protein
levels have been reduced to half their levels have been reduced to half their normal value, death will occurnormal value, death will occur
Lack of any nutrient can cause Lack of any nutrient can cause deficiency diseasesdeficiency diseases
NutrientsNutrients Effects of Effects of deficiencydeficiency
CharacteristicsCharacteristics
ProteinsProteins Kwashiorkor Stomach bloated, growth of Stomach bloated, growth of body and brain retarded, body and brain retarded, no appetite for food, weak no appetite for food, weak bodybody
Vitamin AVitamin A Night blindness
Xerophthalmia
poor night visionpoor night vision cornea dry & opaquecornea dry & opaque
Vitamin BVitamin B11 Beri-beri Swollen legs & ankles, Swollen legs & ankles, numbness in hands, numbness in hands, muscular pain & cramps, muscular pain & cramps, fatigue, loss of appetitefatigue, loss of appetite
Vitamin BVitamin B33 Pellagra Dermatitis (skin becomes Dermatitis (skin becomes red & inflamed), diarrhoea red & inflamed), diarrhoea
& mental disorder& mental disorder
Vitamin B12Vitamin B12
IronIron
Anaemia Lack of RBC or haemoglobin Lack of RBC or haemoglobin to transport oxygento transport oxygen
Vitamin CVitamin C Scurvy Bleeding gums, bruise skin, Bleeding gums, bruise skin, painful & swollen joints, painful & swollen joints, weaknessweakness
Vitamin DVitamin D
CalciumCalcium
Rickets
Osteoporosis
Stunted growth of bones & Stunted growth of bones & teeth, weak bonesteeth, weak bonesBrittle bones which easily Brittle bones which easily brokenbroken
IodineIodine Goitre
CretinismCretinism
Enlarge thyroid glandsEnlarge thyroid glandsPhysical & mental growth Physical & mental growth retardedretarded
SodiumSodium Muscular crampsMuscular cramps Sudden & painful contraction Sudden & painful contraction of musclesof muscles
Effects of Excessive Intake Effects of Excessive Intake of Certain Nutrients on of Certain Nutrients on
HealthHealthNutrientNutrient EffectsEffects CharacteristicsCharacteristics
Carbohydrates Carbohydrates (sugar)(sugar)
Obesity which may which may lead to high blood lead to high blood pressure, diabetes pressure, diabetes mellitus, heart mellitus, heart diseasesdiseasesDental cariesDental caries
Body weight is more Body weight is more than 20% of the than 20% of the suitable body weight suitable body weight for a particular heightfor a particular heightTooth decay due to Tooth decay due to the destruction of the the destruction of the teeth’s enamel by acids teeth’s enamel by acids which are produced by which are produced by bacteria from bacteria from carbohydratecarbohydrate
LipidsLipids Atherosclerosis (as a (as a result of saturated result of saturated
animal fats)animal fats)
The narrowing & The narrowing & hardening of arterieshardening of arteries
ProteinsProteins Gout Stones in the kidney Stones in the kidney
which can damage the which can damage the kidneykidney
Excessive uric acid Excessive uric acid deposits on the deposits on the joints causing joint joints causing joint painpainUric acid crystalises Uric acid crystalises & forms stones in & forms stones in the kidneythe kidney
Vitamin AVitamin A Liver damageLiver damage The liver fails to The liver fails to function because function because liver cells die & liver cells die & fibrous tissues form fibrous tissues form in the liverin the liver
SodiumSodium High blood pressureHigh blood pressureKidney damageKidney damage
Fatigue, headache, Fatigue, headache, can cause bleeding can cause bleeding in the brain (stroke) in the brain (stroke) & heart failure& heart failureKidneys are Kidneys are overloaded with the overloaded with the task of removing task of removing excess saltexcess salt
CalciumCalcium AtherosclerosisAtherosclerosis Calcium deposits Calcium deposits on the inner walls on the inner walls of arteries causing of arteries causing the arteries to the arteries to harden & lose their harden & lose their elasticityelasticity
DIET-RELATED DISEASESDIET-RELATED DISEASES HIGH BLOOD PRESSURE
– Excessive intake of food that is rich in Excessive intake of food that is rich in saturated fat, cholesterol & calcium leads to saturated fat, cholesterol & calcium leads to atherosclerosis & high blood pressure.atherosclerosis & high blood pressure.
– The saturated fats, cholesterol & calcium The saturated fats, cholesterol & calcium are deposited on the inner walls of arteries. are deposited on the inner walls of arteries. The lumen become smaller & the walls of The lumen become smaller & the walls of the arteries harden & lose their elasticity. the arteries harden & lose their elasticity. Blood flow is reduced.Blood flow is reduced. the heart pump the heart pump faster to produce a higher pressurefaster to produce a higher pressure
– Also can cause by excessive intake of Also can cause by excessive intake of salts, tea & coffee which can increase the salts, tea & coffee which can increase the rate of heart beat, thus increasing the rate of heart beat, thus increasing the blood pressure.blood pressure.
– Ways to reduce the risk of HBP :Ways to reduce the risk of HBP : Reduce the intake of food which are rich in Reduce the intake of food which are rich in
saturated fats & cholesterolsaturated fats & cholesterol Exercise frequentlyExercise frequently Reduce the intake of salts in food, as well as Reduce the intake of salts in food, as well as
tea & coffeetea & coffee Do not smokeDo not smoke Have enough restHave enough rest
DIET-RELATED DISEASEDIET-RELATED DISEASE DIABETES MELLITUS
– Caused by excessive glucose in the blood & its Caused by excessive glucose in the blood & its subsequent excretion in the urinesubsequent excretion in the urine
– Excessive intake of food rich in sugar Excessive intake of food rich in sugar (carbohydrates) can cause diabetes mellitus(carbohydrates) can cause diabetes mellitus
– Obesity can also lead to DMObesity can also lead to DM
– The risk of DM can be reduced by :The risk of DM can be reduced by : Reduce the intake of food rich in sugarReduce the intake of food rich in sugar Exercise frequentlyExercise frequently
DIET-RELATED DISEASEDIET-RELATED DISEASE
OSTEOPOROSIS– Due to the lack of calcium, phosphorus & Due to the lack of calcium, phosphorus &
vitamin D in the diet of an adultvitamin D in the diet of an adult– Low density of the bone mass & the bones Low density of the bone mass & the bones
become thin & brittle, easily brokenbecome thin & brittle, easily broken– The risk of contracting osteoporosis can be The risk of contracting osteoporosis can be
reduced in the following ways :reduced in the following ways : Intake of food rich in calcium, phosphorus & vitamin Intake of food rich in calcium, phosphorus & vitamin
DD Exercise frequentlyExercise frequently
KwashiokorKwashiokor
XerophthalmiaXerophthalmia
Beri-beriBeri-beri
PELLAGRAPELLAGRA
ANAEMIAANAEMIA
SCURVYSCURVY
RICKETS
GOITREGOITRE
ATHEROSCLEROSISATHEROSCLEROSIS
OSTEOPOROSOSTEOPOROSISIS
OBESITYOBESITY
GOUTGOUT
HIGH BLOOD HIGH BLOOD PRESSUREPRESSURE
DIABETES DIABETES MELLITUSMELLITUS
EXERCISE 6.3EXERCISE 6.3
1.1.Explain what is Explain what is malnutrition.malnutrition.
2.2.Explain the effects of Explain the effects of malnutrition using examples.malnutrition using examples.
3.3.Describe ways to reduce the Describe ways to reduce the effects of certain health effects of certain health problems.problems.