Infection and Response

How is skin a non specific defence system?

Physical barrier

How is nose a non specific defence system?

Hairs trap pathogens

How is trachea and bronchi a non specific defence system?

Mucus traps pathogens

How is stomach a non specific defence system?

Acid destroys pathogens

How is phagocytosis a specific defence system by WBC?

Ingests pathogens digests and destroys them

How is antibody production a specific defence system by WBC?

Targets a specific pathogen for destruction, remembers pathogen so can be fought quickly next time

How is antitoxin production a specific defence system by WBC?

Cancels out toxins released by pathogens

What is a vaccine?

Small amount of dead or inactive pathogen to stimulate WBC to produce antibodies

How do vaccines work?

• Weak or dead pathogen injected

• White blood cells generate antibodies to destroy pathogen

• White blood cells that make those antibodies remain and make you immune to future infections

Communicable disease definition

A disease which can be spread to others

Pathogen definition

Micro-organisms that cause infectious disease- bacteria, protists, fungi and virus

Bacteria definition

Prokaryotic cells- some cause disease by making toxins

Protists definition

Eukaryotic cells- some cause disease

Fungi definition

Class of organisms that include mushrooms- some cause disease

Virus definition

Smallest organisms- reproduce inside host cells damaging them and causing disease

Droplet inhalation definition

When a disease is spread through coughs and sneezes

Direct contact definition

When a disease is only spread by physical contact

Antibiotics definition

A group of chemicals whihc kill bacteria

Antiviral drugs

A group of chemicals which can prevent viruses reproducing- hard to develop safe ones

Fungicides

A group of chemicals that kill fungi

Painkillers

A type of drug that treats pain symptoms but doesn’t kill pathogens

Lymphocyte

White blood cell

Drug definition

A chemical which alters the body- often extracted from plants and microorganisms

Placebo definition

A pill without the drug in it- taken to check drug effectiveness

Double blind trial definition

When the doctor doesn’t know if they are giving the placebo or the drug- prevents bias

Stage 1 of drug development

Discovery- possible medicines are identified

Stage 2 of drug development

Preclinical trials- tested in labs for toxicity and efficacy on cells, tissues and animals

Stage 3 of drug development

Clinical trials- low doses tested on human volunteers and then people suffering with disease

Stage 4 of drug development

Publishing results- checked by other scientists and approved

What is measles?

A type of virus with a rash spread by drop inhalation- vaccine

What is TMV?

A type of plant virus which discolours leaves spread by direct contact- removed infected leaves

What is HIV?

A type of virus which reduces immune system spread by unprotected sex- antiviral drugs

What is salmonella?

Bacterial- fever, vomiting, spread by food, drink fluids to prevent dehydration

What is gonorrhoea?

Bacterial- thick yellow discharge- spread by unprotected sex- antibiotics

What is rose black spot?

Fungal- black spots on leaves- direct contact- fungicides

What is malaria?

Protist- fever- mosquito bite- use nets, insect repellent