Topics covered• Cells• Digestion• Blood• Circulation System• Gas Exchange• Nervous System• Hormones• Muscles • Skeletal System• Human Reproduction and

Development• Microbes and Immune System

Topics left to cover

• Genetics and Cancer

Human Physiology Lesson 23

Microbes and Disease1. How does your body protect you against from

pathogens2. How can we can become immune to disease?3. What are antigens and how does our body use

them to fight against disease?

Project

• Microbes and Pathogens• Transmission• Entry and protection• Immune System - lymphocytes• Vaccination and Jenner• Developing vaccines• Antibiotics and Fleming• Antibiotic Resistance- C.diff and MRSA

DiseasesBacteria, Food poisoningImpetigoSyphilisTuberculosis

Virus, PolioHIV,Influenza (flu)MeaslesChickenpox

Protoctist, Malaria

Fungi, Athlete’s footThrush

Transmission of Microbes

• How do microbes get transferred from one organism to another?

How microbes are transferred between organisms

• Droplet Infection• Direct Contact• Contaminated food and drink• Through the blood-transfusion or cut

8C Catch that!

Match each sentence with the correct ending:

1 Chicken pox can be spread by… 2 Salmonella can be spread by...  3 Hepatitis and HIV can be spread

by...  4 Colds and flu can be spread by…

5 Typhoid and gastro-enteritis can be spread by…

6 Syphilis and HIV can be spread by…

A…blood transfer. B…sexual intercourse. C…touch. 

D…eating contaminated food.

E…drinking contaminated water.

F…droplets from a cough or sneeze.

C…touch.

D…eating contaminated food.

A…blood transfer. 

F…droplets from a cough or sneeze.

E…drinking contaminated water.

B…sexual intercourse.

8C Infection death rates

Only 5.1% of deaths in Europe are caused by infectious diseases. Do you think that this figure would be different in the developing world? Why?

Pathogenesis

Immunity

• Surface Barriers-prevents micro-organisms from entering the cells of your body.

• Explain the human surface barriers

• Immune System

8C Defence!

How does your body defend itself against an infection

• Platelets• Lymphocytes- engulf and antibody• Antitoxin• Mucus• Hydrochloric Acid• Antibiotics and Fleming• Immunisation

8C Immunity

RECAP

• Mechanisms that stop us from getting ill

What happens if we do get ill?

• How do we know?

Common symptoms of Diseases

Fungal Disease Symptoms

Blemishes on the skin

Itchy, peeling skin

Fever

Spots

Rash

High temperature

Red Eyes

Lethargy

Symptoms

• Write down ANY symptoms of disease

What happens next?

Antibiotics1. Name 3 diseases that antibiotics can be used

against2. Name 3 diseases that antibiotics cannot be used

against3. Why do antibiotics not destroy viral infections?4. Why is it important to ensure that you complete

the dosage of antibiotics you are prescribed?5. What are the dangers in prescribing antibiotics too

readily?

DANGER

MRSA

Antibiotic Resistance

• Natural selection and evolution of bacterial strains.

• MRSA• Mutations • Epidemics and Pandemics

Bacterialpopulation Mutant bacterial cell is

resistant to a specific antibiotic

The resistant bacterial cellsurvives and divides to

generate a population ofantibiotic-resistant

bacteria

Antibiotic Resistance

Spontaneousmutation in

growingpopulation Bacterial population

exposed to antibiotic

• Make a flow chart, including diagrams, about how bacteria develop resistance to antibiotics

Widespread

• What is a main problem caused when new microorganisms emerge?

H5N1

How can we stop a pandemic/epidemic

Bird Flu - A Modern Pandemic?Start the following animation to see how the H5N1 virus could mutate to form a new human flu virus.

How can we reduce the risk of bacteria developing antibiotic resistance?

A 3 year old child suffering from chickenpox

A child suffering from smallpox

How can we protect ourselves from infection?

anthrax malariamumps rubella

measles polio

types of cancer rabies

diphtheria tuberculosisFlu hepatitis

VACCINES

Vaccinations

• Edward Jenner

Vaccination Process

How does it work

Number of Antibodies

Time

First Injection

Booster Injection

Disadvantages

• The MMR debate!

Modern methods of developing vaccines

How can we use the following to help us develop a vaccination?