biology form 4 chapter 6

2. Introduction
 Malnutrition is failing health that result
from not eating a balance diet over a
long period of time.
 Malnutrition refers to undernutrition
resulting from inadequate consumption
or excessive loss of nutrients
 It can also refer to overnutrition resulting
from overeating or excessive intake of
specific nutrients.

3. Some Effects of Malnutrition
 Kwashiorkor
 Caused by protein deficiency
 Often due to poverty in developing nations. Families cannot
afford to feed their young children with high protein food after the
children have stopped feeding on mother‟s milk
 It can be prevented by giving sufficient food containing
protein food to young children
 Symptoms are:
○ Swelling of the legs
○ Underweight
○ “moon face”
○ Swollen abdomen („pot belly‟)
○ Thin muscles but fat present
○ Dry, sparse, thin hair
○ Apathetic, little interest in his surrounding
○ Stunted growth

5.  Marasmus
 Caused by
deficiency of energy
and protein foods in
children
 Symptoms of
marasmus are:
○ Underweight
○ „Old man face‟
○ Thin muscles, thin fat
○ Stunted growth

6. Excessive Intake of Lipids
 Atherosclerosis
 Caused by diets rich in saturated fats and
cholesterol
 The cholesterol deposited below the inner lining
of the arterial wall to form plagues. The plagues
gradually become thicker and harder
 If the coronary artery to the heart is partially
blocked, the person may feel intense chest pain
during strenuous physical exercise or emotional
stress.
 This is because inadequate oxygen is being
supplied to the heart muscles for increased
activities

7. Continue…
 As the coronary
artery becomes
more blocked, there
is insufficient supply
O2 to the heart
muscles. This leads
to a heart attack
(myocardial
infarction)

8.  Hypertension
 Blood pressure is the force of the blood exerted on the
walls of the blood vessels
 The normal blood pressure for an adult is 120/80 mmHg
 May be due to narrowing of the lumen of arteries and
reduced elasticity
 The heart has to pump harder to force the blood through
the vessels
 Hypertension usually gives a measurement of blood at
140/90 mmHg or higher
 It may cause rupture of small arteries in the brain leading
to stoke, heart enlargement, heart attack and renal failure
 Sometimes known as the „silent killer‟. The affected person
who does not go for regular medical check-ups may not be
aware of it until a stroke or heart attack occurs.

10.  Prevention
 A healthy, balanced diet
low in saturated fats and
cholesterol with sufficient
antioxidant vitamins (vit.
A, C and E), whole grain
cereals, nuts, leafy
vegetables and fruits may
help to prevent
cardiovascular disease
 Regular moderate exercise

11. Excessive Intake of
Carbohydrates
 Diabetes mellitus
 Caused by the failure of the pancreas to
produce hormone insulin to regulate blood
glucose levels.
 The kidneys are unable to reabsorb the
glucose. Excess glucose is removed in the
urine.

12. Prevention
 Moderate daily exercises, maintaining proper
weight, eating a balanced diet containing
unrefined carbohydrates and not smoking
 People with mild forms of diabetes can control
their diet and limit the amount and type of
carbohydrate
 They should avoid taking simple sugars
 In more severe cases, diabetics require daily
insulin injections
 Diabetes is not treated, can lead to kidney
failure, cataracts, blindness (diabetes
meningitis) and heart disorder. Wounds will
also be slow to heal

15. Effects of Calcium
Deficiency
 Osteoporosis
 Generally associated with aging. Factors that
increase the risk include low dietary intake of
calcium and vit. D
 It is also caused by decreasing levels of
hormones, for eg. Oestrogen in females after
menopause
 In osteoporosis, there is a progressive loss of bone
density and mineral content. The bones become
thinner, more porous and fracture easily, especially
at the hips, backbone and wrist

17. Prevention
 It is suggested that
people in mid-twenties
and older consume dairy
products daily
 Regular moderate
exercises and not
smoking

18. Rickets
 Rickets is a softening of bones in children due
to deficiency or impaired metabolism of vitamin
D, phosphorus or calcium, potentially leading to
fractures and deformity.
 The predominant cause is a vitamin
D deficiency, but lack of adequate calcium in the
diet may also lead to rickets (cases of severe
diarrhoea and vomiting may be the cause of the
deficiency).
 Although it can occur in adults, the majority of
cases occur in children suffering from
severe malnutrition, usually resulting
from famine or starvation during the early stages
of childhood.

20. The End
~ Appreciate what we have in our life ~