Acidic pH in stomach, saliva in mouth and tears from the eyes are par...
Physiological barriers of innate immunity
Physiological barriers of innate immunity are the natural defense mechanisms that are present in the body to protect against pathogens and prevent infections. These barriers are always present and provide a continuous line of defense against invading microorganisms.
There are several physiological barriers that play a crucial role in innate immunity, and three of them are the acidic pH in the stomach, saliva in the mouth, and tears from the eyes.
Acidic pH in the stomach
- The stomach has an extremely low pH due to the presence of hydrochloric acid (HCl) secreted by the stomach lining.
- The acidic environment in the stomach serves as a barrier against ingested pathogens.
- Most microorganisms cannot survive in the highly acidic environment of the stomach, preventing them from causing infections.
Saliva in the mouth
- Saliva contains various antimicrobial substances, including lysozyme, lactoferrin, and antibodies.
- Lysozyme is an enzyme that can break down the cell walls of certain bacteria, preventing their growth and replication.
- Lactoferrin binds to iron, which is essential for bacterial growth, making it unavailable for bacteria to use.
- Antibodies present in saliva can neutralize pathogens and prevent their entry into the body.
Tears from the eyes
- Tears contain lysozyme, lactoferrin, and antibodies, similar to saliva.
- These components help to protect the eyes from infections by preventing the growth and survival of microorganisms on the surface of the eye.
These physiological barriers act as the first line of defense against pathogens and help in preventing infections. They provide a hostile environment for microorganisms, making it difficult for them to survive and cause harm to the body. These barriers work together with other components of the immune system to provide effective protection against pathogens.
Acidic pH in stomach, saliva in mouth and tears from the eyes are par...
Humoral immunity includes antibodies produced by B-cells.