Immune System Flashcards
What does the Immune System Discriminate Between?
Self (e.g. human)
Other (e.g. non-human)
Healthy (e.g. regular cells)
Defective (e.g. cancer cells, defective embryo)
Pathogenic (e.g. viruses, bacteria, parasites)
What is the primary function of the immune system?
The body’s defense mechanism that distinguishes between self and other entities, and identifying & eliminating pathogens and defective cells
What is the first line of defence of the immune system?
Includes physical, chemical and mechanical barriers like skin, mucous membranes, and stomach acid, which prevent the entry of pathogen into the body
What happens when the first line of defense is breached?
The system detects, signals, recruits, and destroys invading pathogens or abnormal cells through various immune responses.
What are antigens, and what role do they play in the immune system?
Markers for “other” entities, such as pathogens or foreign substances, which trigger an immune response by the body to eliminate them.
What regulates immunity?
Leukocytes (white blood cells)
What role do leukocytes play in this regulation of immunity?
Coordinate immune responses and defend against pathogens & abnormal cells
What is Innate Immunity?
- common to all cells
Immediate (mins-to-hours)
Non-specific
Antigen-presenting cells
No or little memory
What is Adaptive Immunity?
Slow (days-weeks)
Specific
Cell-mediated immunity
Antibody-mediated immunity
Robust memory
What are the 2 general types of immunity?
Innate & Adaptive
What are the 2 general types of immune responses?
Cell-mediated immunity & Humoral immunity
What is Cell-mediated immunity?
Doesn’t involve antibodies
Phagocytosis
Cytotoxic T-lymphocytes
Cytokine release
What is Humoral Immunity?
Involves antibodies
Complement system activation
Antitoxin release
Bacteriolysins
“Molecule based”
What are the major barriers that prevent pathogens from infiltrating cells and tissue microenvironments?
Physical barriers (skin & mucuous membranes), mechanical barriers (tears, coughing, sneezing, GI motility, and ciliated epithelia) and chemical barriers (compromising enzymes, pH, lysozymes, and existing microbiome)
