Unit 1 Biology and disease

Question 1

How do pathogens enter the body?

Answer 1

Gas exchange system - breathe in air containing pathogens - most trapped in mucus lining (these cells have cilia which beat moving the mucus up the trachea into mouth). Some pathogens still able to reach alveoli - where they can invade and destroy cells.

The skin - if damage skin pathogens on surface can enter bloodstream. Blood clots and dries - forming scab to prevent this)

The digestive system - if you eat/drink food containing pathogens most will be killed by acidic conditions of stomach but some may pass and survive into the intestines where they can invade cells of the gut wall.

Question 2

What are pathogens?

Answer 2

An organism that causes disease, produce immune response within the body. (Bacteria, virus, fungi)

Question 3

How do pathogens cause disease?

Answer 3

1. Production of toxins - bacteria release toxins into body (e.g. Vibrio cholera)
2. Cell damage - can physically damage host cells by rupturing them to release nutrients, breaking down the nutrients for own use - eventually starves and kills the cell
3. Pathogen replicates itself inside the cell and bursts them once released

Question 4

What is risk?

Answer 4

A risk factor is something increases the chance of getting a disease.