Intro. to Host Defense: Immune System Flashcards
Distinguish the roles of innate and adaptive immunity including: humoral (antibody-mediated) and cell-mediated immune responses
Innate response- natural immunity, rapid and initial defense, block entry of microbes into tissues, rapidly eliminates microbes that enter tissues includes cell-mediated response (phagocytes)
Adaptive immunity- specific and acquired, develops slowly, more effective defense, includes humoral response (antibody-mediated) and cell-mediated
Define antigens and epitopes and their relationship to immune recognition
Antigen- ANYTHING that can be recognized by the immune system
Epitopes- site or sites within an antigen that binds to receptor
Relationship- epitopes are a region found within an antigen
Explain key properties of adaptive immune responses including: specificity, diversity, memory, clonal expansion, specialization, contraction, homeostasis and non-reactivity to self
Specificity- antigen specific clones bind an antigen at it’s special recognized epitope
Diversity- B lymphocytes able to detect millions of different antigens
Memory- memory B cells activated when the body comes in contact with antigen in a secondary response
Specialization- many types of lymphocytes each with a different role
Contraction- immune response does not last forever (cells undergo apoptosis)
Homeostasis- because of contraction the host is able to maintain homeostasis
Non-reactivity to self- not reacting to host’s own antigens by recognizing as it as not being a threat to the host
Clonal expansion- plasma cells (B lymphocytes) clone antibodies to fight antigen
Describe the general functions of antigen-presenting cells, T and B lymphocytes and NK cells
Antigen presenting cells- capture of antigen for display to lymphocytes
T lymphocytes- mediators of cell mediated immunity
B lymphocytes- mediators of humoral immunity
Natural killer cells- cells of innate immunity
Explain the general roles of generative lymphoid organs peripheral lymphoid organ/tissues and lymphatics in the immune system
Generative lymphoid organs- sites of lymphocyte development (bone marrow, thymus)
Peripheral lymphoid organs/tissues- sites of lymphocyte activation by antigen (lymph nodes, spleen, mucosal and cutaneous lymphoid tissues)
Lymphatic system- system of vessels thought the body that collects lymph and returns it to the bloodstream
Describe the basic concept and significance of lymphocyte recirculation and tissue migration
Lymphocyte recirculation is important to maximize the chances of the circulating lymphocyte to come in contact with a potentially harmful antigen. They are also able to migrate into tissues to fight infections before they enter the blood stream or cause further complications in the infected tissue
Describe the phases and key players in an immune response to a microbe including innate and adaptive immunity
Innate: Phase one of immune response by blocking initial entry of microbes into tissue; key players include dendritic cells, phagocytes, NK cells and complement protein
Adaptive: Phase two of immune response includes phases: antigen recognition, lymphocyte activation, antigen elimination, contraction and memory (if exposed to antigen a second time); key players include antibodies, B lymphocytes, T lymphocytes
Explain the general concepts of immune mediated damage and immunodeficiency and their relationship to disease
Immune mediated damage and immunodeficiency occur when immune cells begin to recognize host cells as potentially harmful antigens. They then begin to attack and destroy host cells causing multiple problems. They can cause disease if the host is treated to suppress these immune cells to stop from attacking itself. This can leave a host immunocompromised and open to other opportunistic antigens.
