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B3 D) Fighting Diseases – Physical & Chemical Barriers
B3 D) Fighting Diseases – Physical & Chemical Barriers
There are many different ways that our body deals with pathogens. All of these different ways fall into two broad categories; prevention and the immune system. We are going to look at prevention in this section and the immune system in the next section.
Prevention is all to do with preventing pathogens from entering the body in the first place. We can split these preventative actions into two categories; physical and chemical barriers. The physical and chemical barriers that we will look at work against many different pathogens; they are not specific to one pathogen.
Prevention is all to do with preventing pathogens from entering the body in the first place. We can split these preventative actions into two categories; physical and chemical barriers. The physical and chemical barriers that we will look at work against many different pathogens; they are not specific to one pathogen.
Physical Barriers
The skin is an example of a physical barrier that prevents pathogens from entering into the body.
When we cut ourselves, there is an opportunity for pathogens to enter the body through the cut, which could result in us becoming infected. However, blood contains platelets that causes blood to clot, which seals the wound and develops into a scab. This prevents the entry of pathogens, thus meaning that an individual does not become infected with any diseases.
The trachea and bronchi secrete mucus which catches pathogens (and other particles). The trachea and bronchi are covered in cilia, which are hair like structures that move mucus to the back of the throat where it is swallowed and taken to the stomach.
The skin is an example of a physical barrier that prevents pathogens from entering into the body.
When we cut ourselves, there is an opportunity for pathogens to enter the body through the cut, which could result in us becoming infected. However, blood contains platelets that causes blood to clot, which seals the wound and develops into a scab. This prevents the entry of pathogens, thus meaning that an individual does not become infected with any diseases.
The trachea and bronchi secrete mucus which catches pathogens (and other particles). The trachea and bronchi are covered in cilia, which are hair like structures that move mucus to the back of the throat where it is swallowed and taken to the stomach.
Chemical Barriers
The stomach produces hydrochloric acid, which is a very strong acid (pH of around 2). The majority of pathogens that enter the stomach are killed by the hydrochloric acid in the stomach. Pathogens enter the stomach when mucus from the trachea and bronchi is swallowed.
Another chemical barrier is in the eye. The eye produces tears that contain lysozyme, which is a substance that kills bacteria on the eye. The skin also secretes antimicrobial substances which kills pathogens.
The stomach produces hydrochloric acid, which is a very strong acid (pH of around 2). The majority of pathogens that enter the stomach are killed by the hydrochloric acid in the stomach. Pathogens enter the stomach when mucus from the trachea and bronchi is swallowed.
Another chemical barrier is in the eye. The eye produces tears that contain lysozyme, which is a substance that kills bacteria on the eye. The skin also secretes antimicrobial substances which kills pathogens.