3.1 Introduction

Unit 1 Cells and Systems

Chapter 3 The immune system protects the human body.

1.1 Observing Living Things

3.1 Introduction Paragraph

150 years ago, surgery was very dangerous because people had a 50% chance of dying right after surgery. This occurs because pathogens were being passed to wounds from the surgeon's hands because they weren't clean from other surgeries. During this time a British surgeon called Joseph Lister had a hypothesis. He thought that if the medical equipment was sterlized to kill the pathogens, maybe the death rate after surgery would be reduced. When doctors tried his suggestion the death rate reduced significantly though many doctors found it ridiculous at first. Today we still follow Lister's guidlines to reduce infections at home and at the hospital.

3.1 Introduction page 100

How are infectious diseases caused?

What is the first and second line of defence?

What is the difference between innate and acquired?

What do pathogens do to you?

Who was looking for a explanation of high death rate?

Was surgery dangerous 150 years ago? Why?

Did Lister's hypothesis work? Explain?

What are infectious diseases?

Do we still follow Lister's guidlines?