Carbohydrates, Proteins and Fats can all be used by the body to release energy and build new cells. Vitamins and Minerals are needed to help health functioning of the body.
A poor diet can lead to someone developing type 2 diabetes or someone being overweight or underweight.
Exercise
Increases the amount of energy used by the body.
Someone will lose weight if the energy that is taken in by food is less than the energy which is used in the day.
People who exercise regularly tend to be more healthier than those who don't.
Metabolic Rate
The time it takes for chemical reactions in the cells of your body to take place.
This can vary depending on the amount of exercise you do. They more you do the higher it is. Also the proportion of fat to muscles in your body,
Can be affected by inherited factors such as Cholesterol.
Bacteria And Viruses
Bacteria
Very Small
Reproduces very quickly
Can produce toxins which make us feel ill.
Illnesses like tetanus, cholera and tuberculosis are bacteria.
Viruses
Smaller than bacteria.
Can reproduce very quickly once there are inside living cells, which then get damaged.
Can produce toxins which make us feel ill.
Illnesses such are colds, flu, measles and polio are viruses.
White Blood Cells
Ingest pathogens
Produce antitoxins to neutralise toxins.
Produces antibodies which destory pathogens. This then leads to immunity from that pathogen.
Treatment Against Diseases
People use painkillers to get rid of the symptoms of a disease. These do not kill pathogens.
Antibiotics are used to kill bacteria.It can not be used to kill viruses. It is difficult to develop treatments which destroy the viruses without damaging the body's tissues or cells.
Antiobiotics have reduced the death rate from infectious bacterial diseases. However some some strains of bacteria (such as MRSA) have developed a resistance to antibiotics, because of overuse and inappropriate use of antibiotics. Bacteria mutates and produces a new resistant strain which means scientists need to continually develop new antibiotics.
Vaccinations
This gives immunity to the particular disease.
An inactive or dead pathogen is injected into the body. The antibodies produced by the white blood cells destroy the pathogen, which then means they gain resistance to it.
Nerves
Nervous System
Consists of the brain, spinal cords, the neurones and receptors.
Allows organisms to react which their surroundings and to coordinate their behaviour.
Information goes from the receptor passes along the neurones to the brain. The brain then coordinates the response which is carried out by an effector.
The effector may be a muscle which can respond by contracting or a gland which responds by releasing chemicals.
Neurons
Motor Neurone. Sensory Neurone. Relay Neurone. These are specially adapted cells that can carry an electrical signal.
They are stretched out to make connections between parts of the body.
They have branched endings to allow a single neurone to act on many muscle fibres.
The cell body has many connections to allow communication with other neurones.
They do not touch each other. There is a gap between them which is called a synapse.
Types Of Receptors
Light - Found in eyes.
Sound - Found in ears.
Change Of Position - Found in ears (balance).
Taste - Found on the tongue. Sensitive to chemicals.
Smell - Found in the nose. Sensitive to chemicals.
Touch, Pressure, Pain and Temperature - Found in the skin.
Conscious action can sometimes be too slow to prevent harm. Reflect action can speed up the response by missing the brain out. It goes : Stimulus > Receptor > Sensory Neurone > Relay Neurone > Motor Neurone > Effector > Response.