GCSE Biology revision

Health issues

Animal tissues, organs and organ systems

AQA 4.1.1.1

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AQA student objectives

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All · Most · Some

ALL 🎯

Identify and describe Defining Health, How Viruses Affect Health and The Immune System and Health in the context of health issues.

MOST 🎯🎯

Explain the relationships between Defining Health, How Viruses Affect Health and The Immune System and Health and how they contribute to health issues.

SOME 🎯🎯🎯

Apply and analyse knowledge of Defining Health, How Viruses Affect Health and The Immune System and Health to interpret unfamiliar information about health issues.

Revision summary

Key knowledge

Read on screen, then print for Cornell-style active revision.

Defining Health

Health is a state of well-being that encompasses both physical well-being (e.g. fitness, BMI) and mental well-being (e.g. stress levels, psychology).
BMI (Body Mass Index) takes into account a person's height and weight to indicate whether they are underweight, normal weight, or overweight.
The absence of disease does not automatically mean a person is in good health, as mental well-being is equally important.

1. Defining HealthAQA

Notes

Health is a state of well-being that encompasses both physical well-being (e.g. fitness, BMI) and mental well-being (e.g. stress levels, psychology).
BMI (Body Mass Index) takes into account a person's height and weight to indicate whether they are underweight, normal weight, or overweight.
The absence of disease does not automatically mean a person is in good health, as mental well-being is equally important.

How Viruses Affect Health

Viruses can destroy human body cells and increase the risk of certain cancers.
Infection with HPV (Human Papillomavirus) can increase the risk of cervical cancer.
Infection with the hepatitis virus can increase the risk of liver cancer.

The Immune System and Health

A weakened immune system increases a person's susceptibility to disease, as it is less capable of fighting foreign pathogens.
HIV (Human Immunodeficiency Virus) weakens the immune system, leaving patients more vulnerable to other infections and diseases.
Immunosuppressants, used to prevent organ rejection after transplants (e.g. heart transplants), also weaken the immune system and increase disease risk.
Immune reactions can trigger allergic responses such as skin rashes, asthma exacerbation, or hay fever caused by pollen.

3. The Immune System and HealthAQA

Notes

A weakened immune system increases a person's susceptibility to disease, as it is less capable of fighting foreign pathogens.
HIV (Human Immunodeficiency Virus) weakens the immune system, leaving patients more vulnerable to other infections and diseases.
Immunosuppressants, used to prevent organ rejection after transplants (e.g. heart transplants), also weaken the immune system and increase disease risk.
Immune reactions can trigger allergic responses such as skin rashes, asthma exacerbation, or hay fever caused by pollen.

Links Between Physical and Mental Health

Severe physical health problems, such as disability, can negatively impact a person's mental health.
Poor mental health can lead to changes in diet, which may in turn cause physical health issues such as obesity.
Environmental factors, including access to medication and healthy food, can significantly affect both physical and mental health.
Stress is associated with autoimmune diseases such as rheumatoid arthritis and can also increase the risk of coronary heart disease.

4. Links Between Physical and Mental HealthAQA

Notes

Severe physical health problems, such as disability, can negatively impact a person's mental health.
Poor mental health can lead to changes in diet, which may in turn cause physical health issues such as obesity.
Environmental factors, including access to medication and healthy food, can significantly affect both physical and mental health.
Stress is associated with autoimmune diseases such as rheumatoid arthritis and can also increase the risk of coronary heart disease.

Communicable Diseases

Communicable diseases (also known as infectious diseases) can be spread from one organism to another and are caused by pathogens.
Malaria is an example of a communicable disease transmitted via mosquitoes, which act as the vector for the pathogen.
Influenza (flu) is a communicable disease spread through droplet infection, such as coughing and sneezing.

5. Communicable DiseasesAQA

Notes

Communicable diseases (also known as infectious diseases) can be spread from one organism to another and are caused by pathogens.
Malaria is an example of a communicable disease transmitted via mosquitoes, which act as the vector for the pathogen.
Influenza (flu) is a communicable disease spread through droplet infection, such as coughing and sneezing.

Non-Communicable Diseases

Non-communicable diseases cannot be passed from one organism to another and are often chronic (long-term) conditions.
Coronary heart disease is a non-communicable disease caused by a build-up of fatty plaques (atherosclerosis) in the coronary arteries, reducing blood supply to the heart muscle.
Cancer is generally a non-communicable disease, as it cannot be spread from person to person.

6. Non-Communicable DiseasesAQA

Notes

Non-communicable diseases cannot be passed from one organism to another and are often chronic (long-term) conditions.
Coronary heart disease is a non-communicable disease caused by a build-up of fatty plaques (atherosclerosis) in the coronary arteries, reducing blood supply to the heart muscle.
Cancer is generally a non-communicable disease, as it cannot be spread from person to person.

Interactions Between Types of Disease

Different types of disease can interact with one another; for example, a communicable disease like HIV can increase susceptibility to further infections.
Certain viral infections (communicable) can trigger non-communicable conditions, such as HPV increasing the risk of cervical cancer.
Mental health conditions can interact with physical health, demonstrating that communicable and non-communicable factors are often interlinked.

7. Interactions Between Types of DiseaseAQA

Notes

Different types of disease can interact with one another; for example, a communicable disease like HIV can increase susceptibility to further infections.
Certain viral infections (communicable) can trigger non-communicable conditions, such as HPV increasing the risk of cervical cancer.
Mental health conditions can interact with physical health, demonstrating that communicable and non-communicable factors are often interlinked.

Epidemiology: Studying Disease in Populations

Epidemiology is the study of how disease interacts with and spreads through a population.
Because populations are too large to study individually, scientists use sampling to collect data from a smaller, representative group.
To avoid bias, samples must be chosen randomly from the population.

8. Epidemiology: Studying Disease in PopulationsAQA

Notes

Epidemiology is the study of how disease interacts with and spreads through a population.
Because populations are too large to study individually, scientists use sampling to collect data from a smaller, representative group.
To avoid bias, samples must be chosen randomly from the population.

Using Sampling to Estimate Disease Prevalence

Sampling allows scientists to hypothesise about the prevalence of a disease across a whole population based on data from a small sample.
Prevalence refers to how widespread a disease is within a population, often expressed as a fraction or percentage.
For example, if 2 out of 6 sampled individuals have coronary heart disease ((2) / (6) = (1) / (3)), we can estimate that approximately one-third (33%) of the total population may also be affected.
The larger and more random the sample, the more reliable and representative the estimate of disease prevalence will be.

9. Using Sampling to Estimate Disease PrevalenceAQA

Notes

Sampling allows scientists to hypothesise about the prevalence of a disease across a whole population based on data from a small sample.
Prevalence refers to how widespread a disease is within a population, often expressed as a fraction or percentage.
For example, if 2 out of 6 sampled individuals have coronary heart disease ((2) / (6) = (1) / (3)), we can estimate that approximately one-third (33%) of the total population may also be affected.
The larger and more random the sample, the more reliable and representative the estimate of disease prevalence will be.