Chapter 8 - Immune System Flashcards
Innate immunity
Composed of defenses that are always active, but that cannot target a specific invader and cannot maintain immunologic memory
- also called nonspecific immunity
Adaptive immunity
Composed of defenses that take time to activate, but that target a specific invader and can maintain immunologic memory
- also called a specific community
Bone marrow
Produces leukocytes
Spleen
Location of blood storage and activation of B cells which turn into plasma cells
Thymus
Site of T cell maturation
Lymph nodes
Provide place for immune cell communication
Humoral immunity
Driven by B cells
Cell -mediated immunity
Driven by T cells
Complement
Proteins in the blood that act as nonspecific defense
- can be activated through classical or alternative pathway
Classical pathway
Binding of antibody to pathogen
Alternative pathway
Does not require antibodies
- punch holes in bacterial walls making them osmotically unstable
Interferons
Given off by virally infected cells and help prevent viral replication and dispersion to nearby cells
Cytokines
Chemical substances that stimulate inflammation and recruit additional immune cells to the area
Macrophages
Ingest pathogens and present them on major histocompatibility complex (MHC) molecules
MHC Class 1 (MHC-1)
Present in all nucleated cells and display endogenous antigen to cytotoxic T cells
MHC Class II (MHC-II)
Present and professional antigen presenting cells and displays endogenous antigen to helper T cells
Endogenous pathway
Binds antigens that come from inside the cell
Exogenous pathway
Antigens originate outside cell
Pattern recognition receptors (PRR)
Recognize category of invader
Natural killer (NK) cells
Non specific lymphocyte; able to detect the down regulation of MHC and induce apoptosis
Neutrophils
Phagocytic cells that follow bacteria using chemotaxis
- most populous
- very short lived
Eosinophils
Involved in allergic reactions and invasive parasitic infections
- release histamine
Lymphatic system
Circulatory system that consists of one-way vessels with intermittent lymph nodes
- Equalizes fluid distribution, transports fats and fat - soluble compounds in chylomicrons, and provides sites for mounting immune responses
