Immunity Flashcards
Innate Immune System
Already have it
the first two lines of defense
typically used for simple infections
Innate Immune System: First line of defense
Using a mechanical “wall” including skin and mucous membranes
First line of defense: Skin
The skin protects the body by simply acting as an air-tight keratinized seal
First line of defense: Mucous membranes
The mucous membranes relies on mucoid secretions to trap potential pathogens
Innate Immune System: Second line of defense
Inflammation and phagocytic leukocytes
Innate Immune System: Inflammation
Inflammation acts as a warning siren that indicates a breach in immunity
Signals a large amount of WBC to gather at the site of inflammation to fight off the attacking antigens
Innate Immune System: Phagocytosis
Neutrophils and Monocytes will engulf pathogens
Innate Immune System: Fever
An environment too hot for pathogens to survive
Innate Immune System: Macrophages
Monocytes that have left the bloodstream and enter any tissue
Can be fixed or mobile
Adaptive Immune System
- Specific
- Utilized when the innate immune system cannot control or contain an infection
- B-lymphocytes and T-lymphocytes
- Does not work unless previously infected by the target pathogen
Adaptive Immune System: B-Lymphocytes
- Specialized lymphocytes
- Involved with producing antibodies
- Mature in bone marrow
- Have a higher level of recognition than neutrophils and monocytes, which allows them to recognize a specific antigen as an invader and a body cell as a natural inhabitant
First-time infection
- An antigen is introduced into the body
- Macrophages capture and break down the antigen
- The antigen parts are presented to a young B-lymphocyte
- The lymphocyte develops a special surface and antibodies that specifically target the antigen
Second-time infection
- The same antigen returns to the body and binds to the corresponding B-lymphocyte before infecting other tissues
- The lymphocyte then activates and differentiates into two types: Plasma Cells and Memory Cells
Plasma Cells
Secretes antibodies that circulate the bloodstream to find surface receptors for the antigens
Memory Cells
Retains the genetic information of the antigen for future protection