immunity and disease

what is a pathogen

It is the microorganism that is responsible for causing diseases to their host

example of pathogen

bacteria, fungi

how can pathogens spread

by direct contact, water, air ,and airborne transmission

how can transmission be reduced or prevented

simple hygiene measures can reduce or prevent the spread of many diseases, such as flu and common cold

what is a vector

an organism that has an active role in transmitting pathogens from one host to another

how to prevent or reduce infection from vector borne diseases

the vectors need to be controlled or humans need to be protected against the vector such as wearing mosquito repellent and wearing long sleeved clothing

how do vaccinations work

it involves putting a small amount of inactive or dead pathogen into your body, which stimulates the body to produce antibodies against the specific pathogen

what are vaccinations

Vaccinations are an option to prevent and reduce pathogens

what are germs

germs are tiny organisms that can multiply quickly and can cause diseases , while some germs are helpful

what is bacteria

bacteria are microscopic , they release toxins in our body making us feel ill

Examples of bacterial infections

Whooping cough , food poisoning and gonorrhoea

what is cholera

it is a bacterial infection caused by contaminated food or water

what is food poisoning

what is food poisoning it is caused by bacteria , viruses or toxins in the food we eat

what are viruses

viruses are an organism that enters the cells and reproduce inside the cell and cause the host cell to explode . They then pass through the airways and bloodstream and spread even more

examples of viral infection

flu (influenza), covid 19 , hiv

what is fungi

fungi is contagious and can pass from direct contact or person to person

what is Protista

some single cell protists can contaminate foods and cause intestinal infection. Protists can also live in other organisms and cause harm.

examples of fungi

athletes foot , and ringworms

example of a protist

malaria, parasite

what is an infectious disease

is an illness caused by the spread of microorganisms or prions to human to human, from animals , or the environment , including food and water

what is a non infectious disease

non infectious diseases are not caused by pathogens and bacteria and therefore cannot be spread from one person to another

example of infectious disease

Influenza, hiv , chicken pox

example of non infectious disease

obesity, diabetes , arthritis

what is the immune system

The body's defense mechanism against disease-causing organisms, malfunctioning cells, and foreign particles.

what does the first line of defence (skin) do

The epidermis, the dead outer layer of skin, acts as a protective shield against potential invaders by secreting chemicals that kill them.

what does the first line of defence (mucus and cilia) do

Foreign particles and bacteria can become stuck in mucus in the respiratory system as you breathe in. Cilia, , sweep mucus into the throat for coughing or swallowing.

what does the first line of defence (saliva)do

Saliva contains many chemicals that break down bacteria

what does the first line of defence (stomach acid) do

Swallowed bacteria are broken down by powerful stomach acids . The stomach must produce a coating of special mucus during the process

The second line of defence (white blood cells)

Invaders enter the body, triggering the attack of white blood cells (WBCs) which circulate throughout the blood, and can enter the body's tissues if invaders are detected.

what are leukocytes

They are white blood cells that flow through your blood stream and protect you against illness and disease such as viruses and bacteria

what are white blood cells (phagocytes )

These white blood cells are responsible for engulfing foreign particles and eating them. The phagocyte breaks down foreign particles into lysosomes, which are organelles that separate them after being engulfed.

White blood cells ( t-cells)

T-Cells, also known as "natural killer" cells, recognize infected human and cancer cells, attack them, kill them, and then continue to search for more cells to kill.

The second line of defence (the inflammatory response)

Injured body cells release histamines, initiating inflammatory responses such as capillary dilation, release of pyrogens, temperature rise, pain receptor activation, and WBCs flocking to infected areas.

Protective factor

living cell

T -cells do what

Kill invaders

Phagocytes

eat invaders

What is the other half of the immune system

Antibody-mediated immunity is the second part of the immune system, which is regulated by antibodies.

The third line of defence (antibodies)

Most infections don't pass the first and second defence levels, but those that do trigger the production and release of antibodies, which bind to specific antigen sites.

What is immunity

Resistance to a disease causing organism or harmful substance

What is active immunity

You produce the antibodies. Those antibodies are produced in the body through past exposure to the antigen, either through actual disease or planned exposure to weakened or killed forms.

What are the 2 types of immunity

Active Immunity, Passive Immunity

how long does active immunity last

some disease-causing bacteria can multiply, requiring annual vaccinations like flu and booster shots to remind the immune system, while others, like chicken pox, last for life.

what is pasive immuntiy

You don’t produce the antibodies. It’s a type of immunity that occurs when a person is given antibodies rather than making them through thier own immune system

how does someone become immune

when particles are quickly recognized, and that person may never become ill from that invader again

what are allergies

Allergies happen when the immune system reacts to a foreign substance that gets inside the body. These substances are known as allergen

symptoms of allergies

congestion, watery eyes, a runny nose, vomiting and, in severe cases, anaphylaxis.

how does allergies affect the body

the immune system may over react by producing antibodies that "attack" the allergen

summary of what the bodies second line of defence is

the bodies general reaction to the pathogen

summary of what the bodies third line of defence is

the bodies specific reaction to the pathogen

what are the two main things that change in the bodies second line of defence

increase in number of white blood cells, and body temperature

what are b -cells

a type of white blood cell that produces antibodies to fight pathogens

how do b-cells fight the pathogens

the antigens they produce puts a lock onto the pathogen and stops the bacteria/virus from entering

what is the bodies major first line of defence

skin /outer body and it physically stops the pathogen from entering inside the body

Ways the body can prevent pathogens from entering

mucus, tears, earwax, and chemical burns

how does non -specific immune response work

works by seeking out and destroying pathogens in a number of different ways , such as blood clotting , inflammation , fever, and the production of leoucocytes

similarities between the second and third levels of defence

both the second and third line of defence are part of the body’s immune system , and act against foreign pathogens . they both trigger inflammation, and phagocytes engulf pathogens

differences between the the second and third levels of defence

The third line of defence is specific where as the second line of defence is non specific. The third line of defence has memory for specific antigens and can mount a stronger response upon subsequent infection, whereas the second line does not have memory

compare different types of vaccines

some vaccines use a dead pathogen , while others break the pathogen up and only inject parts of the original pathogen. Some vaccines use only the genetic material from a viral pathogen , instead of the structure of the pathogen itself

what do all vaccines trigger

the third line of defence to give the body immunological memory against specific pathogens

how can a vaccine prevent a person from catching a disease

it presents the body with part of the pathogen so the body learns to recognise it, and produces antibodies and memory cells that can mount a stronger response in the future if the pathogen is ever encountered again

what happens during the immune system response

Y-shaped antibodies attack pathogens by binding to their surface proteins, blocking their attachment to blood cells. They tag the pathogen, allowing a macrophage to engulf and digest it, thereby preventing the pathogen from attaching to the blood cell.

Auto immune system

where your immune system attacks healthy cells in your body by mistake