Intermediate 1 Biology
Unit 1
Health and Technology
Summary Notes
106757898
Topic 1: What Is Health And Technology?
The Meaning Of Health
There are three sides to health. This is called the health triangle.
Mental
Social
Health
Health
HEALTH
Physical
Health
If any one of these sides were removed then the triangle would collapse.
The same can be applied to your health - if any one side is not right then
you will feel unhealthy.
A healthy lifestyle would include:
o eating an appropriate range of foods
o taking regular exercise
o taking part in pleasurable activities
o taking regular relaxation
o avoiding unnecessary health risks such as smoking
cigarettes, drinking alcohol and taking drugs.
106757898
Physiological Measurements
Taking certain physiological measurements can give an indication of the
health of the person.
Some measurements would include:
o temperature
o body fat
o blood pressure
o heart (pulse) rate
These measurements can be taken using Low-tech and High-tech
approaches.
Physiological
Measurement
Temperature
Body fat
Blood pressure
Heart (pulse rate)
2
Low-tech Approach
High-tech Approach
Thermometer
Thermocouple or
thermistor
Skin fold callipers
Digital body fat sensor
Stethoscope and
mercury manometer
Digital
sphygmomanometer
Finger and stopwatch
Pulsometer or heart
rate monitor
106757898
Topic 2: A Healthy Heart
The Heart And Circulatory System
The heart is made of muscle and pumps blood around the body. As the
heart muscle contracts and relaxes blood is pumped through vessels to
the different parts of the body.
There are valves in your heart which make sure that the blood always
flows in the right direction. The closing and opening of these valves can
be heard as heart beats when you listen to someone's chest.
Diagram of a human heart
blood vessels
There are three kinds of blood vessels:
 arteries
 capillaries
 veins.
Arteries carry blood away from the heart. They divide again and again
and form very tiny blood vessels called capillaries.
Capillaries allow nutrients and oxygen to pass from the blood to the
tissues and allow carbon dioxide and other wastes to leave tissues. The
capillaries join up with one another to form large vessels called veins.
Veins return blood to the heart.
106757898
Diagram of artery, capillary and vein
from heart
artery
vein
capillary
to heart
Diagram of a capillary bed
The diagram below shows blood flow around the body.
Arrows show direction
of blood flow
veins
arteries
The heart pumps blood to the lungs and the rest of the body.
106757898
Pulse Rate As A Health Indicator
When the heart beats it pushes blood into our
arteries and makes them grow out a little. This
causes a pressure wave which can be detected as
a pulse.
Pulse rates are expressed as beats per minute and measure the speed
that your heart is beating. It can be measured using a pulsometer or
heart rate monitor.
Resting Pulse.
Measuring our resting pulse rate indicates how fit
we are. It shows the efficiency of the heart and
circulation.
The normal pulse rate is between 60 - 70 beats per
minute.
A high resting pulse rate means that the heart is having to work hard to
pump blood round the body. This can lead to heart disease.
A low resting pulse rate and a short recovery time (i.e. the time for the
pulse rate to return to normal after exercise) can indicate fitness.
The resting rate can be reduced by taking regular exercise.
106757898
Blood Pressure Under Different Conditions
Blood pressure is the pressure of our blood in our arteries. This pressure
is caused by the pumping action of the heart.
Our blood pressure changes depending on
 our emotional and physical conditions
 where the arm is placed during the measurement
 how and where the cuff is fastened.
Traditionally blood pressure is measured by using a stethoscope and a
mercury manometer.
Blood pressure is taken as two readings:
 the first, higher pressure, is caused when
the heart contracts and pushes blood into
the arteries.
 the second, lower pressure, is caused when
the heart relaxes, refilling with blood,
(It is measured in millimetres of mercury.)
It is written as 110/75, if the first reading is 110 and the second is 75.
High blood pressure can be caused by a number of factors:
o being overweight
o lack of exercise
o incorrect diet (too much salt in food)
o drinking excessive amounts of alcohol
o stress.
High blood pressure usually affects adults over 35 years old and can lead
to heart attack or stroke.
Low blood pressure is uncommon but can lead to fainting or indicate heart
failure.
6
106757898
Blood Tests And Blood Counts
Our blood can be checked to find out the state of our health. This
will also detect and monitor various illnesses.
Blood laboratories can do three types of blood tests using "high tech"
equipment.
Blood tests and cell counts can be used to detect:
 Anaemia – by measuring iron content and red blood cell numbers
 Infection – by the presence of microbes and/or the presence of
antibodies
 Leukaemia – by counting number of white blood cells
 Diabetes – by measuring sugar content
 Blood groups – due to types of red blood cells (A, B, AB, 0), types of
antibodies.
7
106757898
Topic 3: Healthy Lungs
The Lungs And Breathing
Our lungs are found inside our rib cage and they are on either side of the
heart. The lungs are spongy, pink in colour and are made up of millions of
air sacs. The lungs take in oxygen into the blood and remove carbon
dioxide from the blood to the air.
Exercise improves the efficiency of gas exchange in the lungs.
Diagram of the human breathing system
8
106757898
The Physiological Measurements Of The Lungs
The measurement of Vital Capacity and the Tidal Volume allow us to
measure the state of the health of our lungs.
The Vital Capacity is the maximum volume of air we can breathe out after
we have taken a deep breath.
The Tidal Volume is the normal volume of air breathed in and out from
our lungs.
The Peak Flow is a measure of the maximum
rate at which air can be forced from the
lungs. The Peak Flow rate can be used as a
measurement of health e.g. it can be used in
the diagnosis and management of asthma.
Peak Flow Meter
The Vital Capacity, Tidal Volume and Peak Flow of a person depends on
 the age,
 sex,
 size
 fitness of the person.
Health Risks And Effects Of Smoking
Smoking increases the risk of cancer and heart diseases. Carbon
monoxide is a poisonous gas found in cigarette smoke. This gas reduces
the oxygen carrying capacity of
the blood.
9
106757898
Topic 4: A Healthy Body
The Importance Of Diet And Energy Balance
The food and drink we eat everyday makes up our diet.
A healthy diet contains a balance of all the important
nutrients:
 Carbohydrates
 Proteins
 Fats
 Vitamins and minerals
 Fibre
 Water.
A balanced diet should include a variety of food including
 lots of fruit and vegetables
 only a small amount of foods with sugar and fat.
Energy giving nutrients are
o carbohydrates found in food like cereals, bread and potatoes.
o fats found in butter, margarine and bacon.
Body building nutrients are
o proteins found in fish, meat and peanuts
Protective nutrients are
o vitamins and minerals found in fresh fruit and vegetables.
106757898
Topic 4: A Healthy Body
The Relationship Between Fat And Health
About half the population in Britain are overweight and about one-fifth
of them are obese. (very overweight) Anyone who is obese is likely to
suffer from serious diseases such as coronary heart disease or diabetes.
A person's diet or eating habits is one of the many factors that
determines a person's weight.
Being overweight can lead to an increased risk of:
o heart disease
o kidney failure
o arthritis
o diabetes.
Being underweight can indicate illnesses such as:
o cancer
o anorexia.
The amount of body fat can indicate the health of a person.
A skinfold calliper measures the thickness of a fold of skin with its
underlying layer of fat. This is carried out on different part of the body
to represent the total amount of fat on the body. You can estimate the
total percentage body fats of a peron, using these measurements. The
body should have about 20% fat.
106757898
The Relationship Between Body Temperature And Health
Our body temperature needs to be kept between
36oC - 37.3 oC.
Our body temperature can alter slightly depending on:
 where it is measured
 the time and day
 for women the time of the month (menstrual cycle) is also a factor.
A thermostat in our brain maintains a constant body temperature.
High temperature.
A body temperature above 40 oC
 can lead to heatstroke
 indicate fever as a result of fighting infection.
Low temperature.
A body temperature below 35 oC indicates
hypothermia. If the body temperature falls below
30oC, death can result. Babies and the elderly are particularly at risk.
106757898
Exercise And The Health Of Muscles
Most of the energy obtained from food is used to help us move. All
movement is brought about by the action of muscles.
How muscles work.
When a muscle contracts it becomes shorter, and this causes a bone to
move. Muscles must work in pairs. One muscle contracts to bend the
limb and the other contracts to straighten the limb. While one of the
pairs of muscles contracts, the other muscle relaxes and returns to its
original shape.
Diagram of muscle pairs in the arm
Muscle strength and endurance are good ways of
measuring someone's physical fitness, but not
necessarily the general state of health.
To improve the strength of our muscles, exercise
them regularly. Muscles then grow larger, and
develop a better blood supply. As a result muscles
increase in strength and become more efficient.
Muscle mass decreases if muscles are not
exercised regularly. Muscle fatigue (tiredness)
can be relieved by relaxation.
13
106757898
Reaction Time As An Indicator Of Health
Reaction time is the time taken for a person before he/she can respond
to a certain stimulus. Reaction time is a good health measurement
indicator. It can be measured in many ways, measuring the time taken to
do a simple task e.g. catch a dropped ruler.
A slow reaction time can indicate diabetes, brain or nervous disorders or
arterial disease.
Our reaction time can be affected by:
o drugs
o alcohol
o excitement.
Health Risks And The Effects Of Alcohol
The effects of drinking small amounts of alcohol occasionally are short
term and will not harm your body. However, alcohol is a depressant drug
and small amounts can slow down processes in your brain.
In the long term, drinking can cause:
o liver damage
o brain damage.
In the short term, alcohol in the blood leads to:
o reduced reaction time
o poor muscle control
o impaired judgment.
14