Humoral
It is called the adaptive defense and consists of antibodies and lymphocytes, often called the humoral response.
T helper cells
The part of the immune response that is specific to a particular pathogen is the adaptive immune response. This response involves the activation of lymphocytes, particularly T cells and B cells, which recognize specific antigens presented by the pathogen. B cells produce antibodies that target these antigens, while T cells can directly kill infected cells or help orchestrate the immune response. This specificity allows for a tailored and effective defense against distinct pathogens.
Memory cells are long-lived cells that "remember" specific pathogens and help mount a faster and stronger immune response upon re-exposure. Effector cells, on the other hand, are specialized cells that actively participate in the immune response by directly eliminating pathogens. Memory cells are part of the adaptive immune system, while effector cells can be part of both the innate and adaptive immune responses.
If a pathogen crosses the second line of defense, which includes innate immune responses like inflammation and phagocytosis, the body activates the adaptive immune system. This involves the activation of lymphocytes, such as T cells and B cells, which specifically target and eliminate the pathogen. The adaptive response also generates memory cells, providing long-lasting immunity against future infections by the same pathogen. If the adaptive immune response fails, the infection can progress and potentially lead to illness.
Helper T cells
Regional lymph nodes where they present to T cells, activating the adaptive immune response.
Cytotoxic T cells play a crucial role in the adaptive immune response by identifying and destroying infected or abnormal cells in the body. They recognize specific antigens on these target cells and release toxic substances to kill them, helping to eliminate the threat and prevent further infection.
The third line of defense against pathogens in the body is called the adaptive immune response. This response involves the activation of specific lymphocytes, such as T cells and B cells, which recognize and target specific pathogens. Unlike the innate immune response, the adaptive response develops memory for previously encountered pathogens, allowing for a faster and more effective response upon re-exposure. This system is crucial for long-term immunity and protection against various diseases.
Immunity is conferred primarily through two mechanisms: innate and adaptive immunity. Innate immunity provides immediate, non-specific defense against pathogens, utilizing barriers like skin and mucous membranes, as well as immune cells like phagocytes. Adaptive immunity, on the other hand, develops over time and involves the activation of lymphocytes (B cells and T cells) that specifically recognize and remember pathogens, leading to a targeted and lasting immune response. Vaccination can enhance this adaptive response by introducing antigens, prompting the immune system to produce memory cells without causing disease.
Antibodies are proteins produced by the immune system that help identify and neutralize harmful pathogens like viruses and bacteria. They play a crucial role in the adaptive immune response by recognizing specific antigens on these pathogens and marking them for destruction by other immune cells. This targeted response helps the body fight off infections more effectively.
Myeloid cells are a group of blood cells that originate from bone marrow and play crucial roles in the immune response. They include various types of cells such as monocytes, macrophages, neutrophils, eosinophils, basophils, and dendritic cells. These cells are involved in processes like phagocytosis, inflammation, and the adaptive immune response. Myeloid cells are essential for both innate and adaptive immunity, contributing to the body's defense against pathogens and tissue repair.