Zusammenfassung der Ressource
Biology B1
- Fitness and blood pressure
- Fit and healthy
- Healthy means being
free of diseases
- Fit is how well you can
perform physical tasks
- Fitness
- Can be measured through...
- Strength
- Speed
- Agility
- Flexability
- Blood pressure
- Blood is pumped around
your body by contractions
of your heart
- It leaves your heart and
then flows around your
body through arteries
- It then flows back to
your heart through veins
- Healthy blood pressure
should be about 135
(systolic) and 85 (diastolic)
- Factors that increase
your blood pressure...
- Smoking
- Being overweight
- Too much alcohol
- Being under lots of stress
- Low blood pressure
- It causes poor circulation
which means that tissues
don't get enough food
and oxygen
- You could end up feeling dizzy and fainting
- High blood pressure
and heart disease
- Smoking
- Smoking raises
blood pressure
- Chemicals
- Carbon monoxide
- It combines with the
haemoglobin in red blood
cells, and so reduces the
amount of oxygen they are
able to carry
- Nicotine
- Increases heart rate
- Poor diet
- Saturated fats
- Cholesterol is a fatty substance
- You need some
cholesterol for making
cell membrains
- Too much forms plaques on
the artery walls which
narrows the arteries and
restricts the flow of blood
- High salt levels
- You need some salt but
too much can cause high
blood pressure
- It causes damage to
the arteries, which can
lead to a heart attack
- Narrow arteries
- The heart gets blood from
the coronary arteries
- If these become narrowed
the heart gets less oxygen
- A thrombosis (blood
clot) restricts blood flow
- If a blood clot happens in a
narrowed artery, the blood flow
might be cut off completely
- This causes a heart attack
- Eating Healthily
- Balanced diet
- Carbohydrates
- Provide energy
- Fats
- They provide energy, act
as an energy store and
provide insulation
- Protiens
- They are needed for
growth and repair of tissue
- Vitamins and Minerals
- They have various functions
- Vitamin C prevents scurvy
- Iron is needed to produce haemoglobin
- Water
- To prevent dehydration
- Needs may vary
- Age
- Children need
protein for growth
- Old people need calcium to protect
against bone diseases like osteoporosis
- Physical activity
- More active people need
more carbohydrates for
energy
- Gender
- Females need iron to
replace iron lost during
the menstrual cycle
- Different diets
- Religious reasons (e.g.
Hindus don't eat cow
because they are sacred)
- Personal reasons (e.g.
Vegetarians don't eat
meat because they
think that it is cruel)
- Medical reasons (e.g.
some people may be
allergic to some foods)
- Diet problems
- Not enough protien
- Causes kwashiorkor
- A common symptom is
a swollen stomach
- In developing countries
many people have diets
that are too low in protein
- Overpopulation - there just
isn't enough protien-rich
food for everyone
- Money - there isn't enough money
to invest in proper agriculture
- E.A.R.
- EAR (g) = 0.6 x body mass (kg)
- Estimated average
daily requirement
of protein
- It is just an estimate
- EAR varies with age, (e.g.
children need more protein
because they are still growing
- Pregnant women need extra
protein to help their baby grow
- Eating disorders
- Anorexia nervosa
- It leads to self-starvation
- Bulimia nervosa
- It involves binge eating followed
by self-induced vomiting
- BMI
- BMI isn't always reliable,
muscle weighs more than fat so
people with lots of muscle may
come out with a high BMI
- BMI = Body Mass Index
- BMI = body mass (kg)
over height (m) squared
- Weight descriptions
- Below 18.5 -
underweight
- 18.5 - 24.9 -
normal weight
- 25 - 29.9 -
overweight
- 30 - 40 -
moderately obese
- Above 40 -
severely obese
- BMI is used to decide if
someone is underweight,
normal, overweight or obese