Lecture 6: Innate Immunity Flashcards
Define immunity and the immune system.
Immunity = resistance to disease
Immune system: functional system rather than an organ system.
What are the four classes of pathogens that the immune system protects us from?
Bacteria, viruses, fungi, parasites (protozoa, worms)
What is contained within the lymphatic system?
Bone marrow, lymphatic tissues, lymphatic vessels, lymph
What are the functions of the lymphatic system?
Circulate body fluids, defend the body against disease
The lymphatic organs/tissues are classified into 2 gorups. Describe the primary lymphoid organs.
Where pluripotent stem cells differentiate and become immunocompetent. Contains red bone marrow and thymus.
Describe secondary lymphoid organs/tissues.
Sites where immune cells continue their maturation and connect with each other, where most immune responses occur. Lymph nodes, spleen, lymphatic nodules/follicles.
Where is red bone marrow found? What happens within it?
Found in flat bones/epiphyses. Pluripotent stem cells become immunocompetent cells and immature T cells.
Where is the thymus found? What does it do?
Found on top of heart in mediastinum. Where pre-T cells become mature.
What are the three secondary lymphoid organs/tissues and their general functions?
Lymph nodes: where cells of adaptive immune system ‘meet up’
Spleen: removal of damaged RBCs
Lymphatic nodules: mucosal surfaces, tonsils (no capsule)
Name some differences between the innate and adaptive immune systems.
Non specific/highly specific.
1st line of defense/3rd line
Surface barriers/specific cells and proteins
no memory/has memory
Describe how the epidermis acts within the ______ immune system.
Innate (1st line). Sheds periodically, removing microbes, very dense so hard for bacteria to get through.
What are the three types of mucous membranes that are apart of the ______ immune system?
Innate (1st line). Mucous = traps microbes and foreign substances.
Hairs = trap and filter microbes. Cilia = projections on epithelial surfaces that eject/destruct pathogens.
What do lysozymes do?
Enzyme that breaks down cell walls of certain bacteria. Present in tears, saliva, sweat, other secretions.
What are the six bodily fluids apart of the _________ immune system?
Innate (first line). Saliva, urine, vaginal secretions, vomiting/shit, sebum, sweat, gastric juices.
What are the four varieties of cells and factors that act as internal defenses within the innate immune system?
Antimicrobial proteins, natural killer cells, phagocytes, inflammation.
What do interferons do? Iron-binding proteins?
Interferons are small secreted proteins that interfere with viral replication. Iron-binding proteins inhibit the growth of bacteria by binding iron.
What do complement proteins do?
Collection of proteins that “complement” the antibacterial activity in the body, opposing pathogens.
What do antimicrobial proteins target?
Attract dendritic cells and mast cells.
What are the three pathways of activation for the complement system? What are they triggered by?
Classical - antibody triggered.
Alternative - pathogen triggered.
Lectin - activated by binding of lectin-like proteins.
Natural killer cells are large, granular ________. They are found in ______ and ____. They kill altered cells by ______ and _________, then release _________.
Lymphocytes, blood, tissue, perforin and granzyme, cytokines
What do perforin and granzyme do?
Perforin = makes hole in cell.
Granzyme = enters & causes apoptosis.
What are the 5 phases of phagocytosis?
Chemotaxis, adherance, ingestion, digestion, killing
What three cells can be phagocytes?
Neutrophils, monocytes/macrophages, dendritic cells
How do phagocytic cells know what is a pathogen?
Use pattern recognition receptor (PRRs) to see pathogen-association molecular patterns (PAMPs). This causes secretion of pro-inflammatory cytokines.
