Human defences against diseases

How is the nose a non-specific defence against disease that works against all pathogens, to try and stop them entering the body?

The nose traps particles that may contain pathogens,

The white blood cells also use as help to defend against pathogens the production of special protein molecules called antibodies which attach to antigen molecules on the pathogen, describe the process for this?

Antigens are markers on the surface of the microrganism, the white blood cells become sensitised to the antigens and produce antibodies, the anitbodies then lock onto the antigens and this causes the microorganisms to clump together, so that other whiteblood cells can digest them.

What would be an example of immunity in order to reflect what immunity really is and what we call it?

If the same pathogen re-enters the body, the white blood cells respond more quickly to produce the correct antibodies, this quick response prevents the person from getting ill and is called immunity.

Why does smallpox not exist anymore?

This is because vaccination managed to prevent the pathogen spreading to new hosts. Scientists are hoping to repeat this with polio.

How are the enzymes in tears a non-specific defence against disease that works against all pathogens, to try and stop them entering the body?

enzymes in tears destroy microorganisms

How are the sebaceous glands a non-specific defence against disease that works against all pathogens, to try and stop them entering the body?

sebaceous glands (under skin and under but on hairs) produces sebum, which kills bacteria and fungi

How are the glands in the stomach a non-specific defence against disease that works against all pathogens, to try and stop them entering the body?

Glands in stomach wall produce hydrochloric acid, which kills bacteria

How is the goblet cell, mucus and cilia a non-specific defence against disease that works against all pathogens, to try and stop them entering the body?

Goblet cells secrete mucus and so when mucus emerges sheets of it traps particles and bacteria as well as cilia which create a wave motion sweeps along the mucus elsewhere.

How does the immune system react to a pathogen entering the body?

If a pathogen enters the body, the immune system tries to destroy it.

How do white cells help to defend pathogens through phagocytosis?

White blood cells help to defend against pathogens through; phagocytosis, which involves the pathogen being surrounded, engulfed and digested.

What is the process for phagocytosis used by white blood cells as help?

This is the process in which it all happens; Microorganisms invade the body. The white blood cell finds the microorganisms and engulfs them. The white blood cell ingests the microorganisms and now the microorganisms have been digested and destroyed

How are antibodies specific?

Antibodies are specific to a particular pathogen e.g. antibodies against gonorrhoea bacteria will not attach to salmonella bacteria.

How do the white blood cells use as help the production of antitoxins?.

Antitoxins are chemicals that neutralise the poisonous effects of the toxins

What happens when a vaccination is taken by a person and how does it stimulate white blood cells?

When a person has a vaccination, small quantities of dead or inactive forms of a pathogen are injected into the body, vaccination stimulates the white blood cells to produce antibodies and to develop immunity

What must we do to some vaccinations that carry a very small risk of side effects?

Some vaccinations do carry a very small risk of side effects, but it is important to compare this with the risk of getting the disease.

What happens to the spreading of a pathogen if large proportion of a population is immune to a certain pathogen?

The pathogen cannot be spread easily

What does a vaccination do?

a weakened/ dead strain of the microorganism is injected. Antigens on the modified microorganisms surface cause the white blood cells to produce specific antibodies

white blood cells that are capable of quickly producing the specific antibody remain in the bloodstream.