Disease

Question 1

Define disease

Answer 1

Anything that causes your body to stop working properly

Question 2

Define antibiotics and explain the origins

Answer 2

Antibiotics are substances that kill or preempt the growth of bacteria.

Question 3

Describe the first line of defence against disease and outline how each works

Answer 3

To prevent the pathogens (bacterial disease) from entering the body.
Does this by;
-skin acting as a Barrier and protects internal organs
-air entering the nose is filtered by hairs in the nose
- pathogens entering digestive system are killed by acids in the stomach
-tears and saliva (fluids) wash away harmful substances entering the openings on the body

Question 4

Describe and outline the second line of defence

Answer 4

The effected area becomes inflamed which is a response of the body to infection. The damaged cells release histamine which causes more blood flow the the area. Within those blood cells are neutrophils which consume bacterium.

Question 5

Third line of defence and how it works

Answer 5

Lymphatic system. These contain large numbers of white blood cells, the function of these white blood cells is to kill pathogens in large clusters allowing macrophages to kills more pathogens at any one time.

Question 6

Explain why hygiene is important and how food poisoning occurs by bacteria e.g. Salmonella

Answer 6

You can prevent disease by practising good hygiene. Salmonella causes gastroenteritis. This can be prevented if you wash your hands frequently, wash surfaces before eating and refrigerate foods.

Question 7

Describe the nature of viruses and how they invade host cells. Identify that antibiotics cannot kill a virus.

Answer 7

Viruses are pathogens and 100 times smaller then bacteria. Viruses grow and reproduce inside host cells (cells they have invaded). It uses the host cells to make thousands of copies. the host cell is destroyed when it burst open and releases new viruses that spread throughout the body infecting then destroying other cells.

Question 8

Define pathogen

Answer 8

Bacteria that causes disease

Question 9

Infectious

Answer 9

Diseases that can spread

Question 10

Non-infectious

Answer 10

Diseases that cannot spread

Question 11

Epidemic

Answer 11

A widespread occurrence of an infectious disease

Question 12

Pandemic

Answer 12

Disease prevalent over a whole country or world