Initial Responses of Immune Systems
Immune systems are critical for protecting organisms from damage caused by infection by external pathogens or internal malfunctions, e.g. prions and cancer. Immune systems try first to prevent being infected by a pathogen. This is achieved in various ways by animals and plants using three main strategies of physical, chemical and microbiota barriers. Then, if those barriers fail, humans have further responses (such as white blood cells and inflammation) to continue defending themselves.
The innate immune system is constantly trying to identify and defend against all pathogens. It therefore needs to be able to distinguish between what is part of an organism’s own body and what is foreign. Innate immune system cells and components do this by looking for biological information markers called antigens.
(Some images in this video are sourced from OpenStax. (n.d.). Biology. OpenStax. Retrieved December 17, 2024)
This resource revises initial responses of immune systems and within this topic there are 4 key concepts:
- Barriers preventing pathogen infection
- Key leukocytes of the innate immune system
- Antigens and the initiation of an immune response
- Other innate immune system actions
To determine if this resource will benefit you, start by answering the following questions.
- What are the three types of barriers to pathogens entering a human or plant?
- What are the difference between pathogens, antigens, and antibodies?
- What are the different components of the innate immune system and a key role for each?
The answers to these questions are provided on the following pages. Use this resource to refresh your memory, reinforce your understanding of these concepts, and prepare more effectively for university-level learning.