CHP 1: Intro, Organs and Cells Flashcards
Define Immunity
State of being resistant to infection by a pathogen
What is the mechanism organisms use to defend themselves against microorganisms?
Immune response
What is germ theory of disease?
Diseases are caused by the invasion of pathogens
Define pathogen. What are the types of pathogens?
Microorganism with the potential to cause disease
Types of Pathogens:
1) Bacterial
2) Viral
3) Fungal
4) Parasitic
5) Protozoa
Who created the first vaccine?
Edward Jenner
How did Edward Jenner come to the hypothesis that cowpox provided protection against smallpox?
Farmers were not getting ill from smallpox due to unsuccessful variolation of the pathogen
What is the cellular theory of immunology?
Theory that cells were responsible for immune responses specifically through phagocytosis
What is the humoral theory of disease?
Illness was due to the imbalance of bodily fluids specifically: blood, phlegm, yellow bile, and black bile
What is the humoral theory of immunology?
Theory that proposes that immunity is mediated by substances present in the body fluids
Humoral immunity is also called or known as?
Antibody-mediated immunity (B-cells)
Is an immune response that does not rely on the production of antibodies?
Cell-mediated immunity
(use of T-cells)
What is an opportunistic pathogen?
A pathogen that ONLY causes disease WHEN immune system is NOT functioning properly
T/F: Viruses are intracellular pathogens
True
What are the two types of immunity we have?
Innate immunity and Adaptive immunity
What is the difference between innate immunity and adaptive immunity?
Innate or natural immunity is our inborn ability of the body to resist, genetically transmitted from one generation to the next
Adaptive or active immunity is developed by the host after exposure to an antigen or after transfer of antibodies from an immune donor
T/F: Innate immunity lacks immunological memory
True
Which type of immunity is capable of specially recognizing and selectively eliminating foreign microorganisms and macromolecules?
Adaptive (Active) Immunity
T/F: B cells are part of the adaptive immune system
True
Immunoglobulin is also known as?
Antibodies
Who concluded that microorganisms were responsible for the cause of postpartum fever transmission?
Louis Pasteur
Who suggested to doctors to wash their hands prior to assisting with deliveries to reduce the risk of postpartum fever deaths?
Ignaz Semmelweis
Who developed four criteria for determining if a microorganism causes a specific disease?
Robert Koch
What is variolation?
Smallpox lesion injected under the skin of healthy individuals to promote protective response (exposure to skin lesions of an individual carrying the disease)
What are our three lines of defense in our immune system?
1) Physical Barrier (Skin and mucousa)
2) Innate Immunity
3) Adaptive Immunity
What is a key function a leukocyte MUST have to qualify as being part of the adaptive immune response?
Must have the ability to present an antigen
Which white blood cell has both innate and adaptive immune responses?
Dendritic Cells
T/F: B cells activate and differentiate into plasma cells once exposed to a foreign antigen
True
In regards to the immune system, tolerance is?
The ability for our immune system to inactivate a response due to exposure to self or unharmful foreign substances
Which antigen presenting cell promotes the movement of antigens to a draining lymphoid tissue to active the adaptive immune response?
Dendritic Cells
What is the function of proteases?
Degrade/breakdown proteins - Hydrolysis of peptide bonds
What is the function of lysozyme?
Degrade/breakdown bacterial cell walls – Gram (+) microbes who have a peptidoglycan wall
What is the function of defensins?
Disruption of pathogenic membranes
What are some chemical barriers epithelial cells have? (4 total)
1) Low, acidic pH
2) Protease
3) Lysozymes
4) Defensins
What are some physical barriers our skin or epithelial cells have to reduce pathogenic invasion?
1) Tight Junctions - decreases/blocks passage
2) Extracellular fluid flow - inhibits attachment
What is the process of formation of blood cells?
Hematopoiesis
Hematopoietic cells differentiate into which two progenitor cells?
1) Common lymphoid precursor
2) Common myeloid precursor
Monocytes can differentiate into which two cells?
Dendritic cells and macrophage
Which cell is responsible for the formation and production of platelets?
Megakaryocyte
Which leukocytes are also considered granulocytes? Why are they referred to this too?
1) Neutrophils
2) Eosinophils
3) Basophils
4) Mast Cells
Because they have granules within their cytoplasm
What is the most abundant leukocyte?
Neutrophils
Which leukocyte is responsible for defending against parasitic worms?
Eosinphils
Which leukocyte is the first line of defense on protecting the body against infection?
Neutrophils
Which cell gives rise to all cell types within the blood?
Hematopoietic Stem Cell
What are the three cell lineages within the circulatory system?
1) Erythroid - gives rise to blood cells and platelets
2) Myeloid - gives rise to leukocytes
3) Lymphoid - gives rise to adaptive immune cells, NK cells, and ILC
T/F: B cells and T cells are leukocytes
True; they are a type of white blood cell called lymphocyte
What granules do neutrophils have? How does this correspond to its function?
Myeloperoxidase, B-glucuronidase, elastase, cathepsin G, lysozyme, and lactoferrin.
These granules give neutrophils the ability to break down a variety of molecules in order to engulf – primary function is phagocytosis as well as tissue remodeling
Which granulocyte(s) are non-phagocytic?
Basophils
Which granulocyte contains histamine?
Basophils
Which granulocyte plays a key role in allergic reactions? What does it release to cause this?
Basophils; Histamine
Which leukocyte is important for fighting against parasitic infection and has low phagocytic activity?
Eosinophils
T/F: B cells, macrophages, and dendritic cells are all antigen presenting cells
True
What are the three major functions of a macrophage cell?
1) Phagocytosis
2) APCs
3) Secretion of cytokines to stimulate inflammation
ILC’s secrete?
Cytokines to activate innate immune cells
Which innate cell is able to recognize and destroy viral-infected cells?
NK cells
The lymphoid progenitor gives rise to which innate cells?
NK cells and ILC’s (innate lymphoid cells)
T cells differentiate into?
Cytotoxic T cells and Helper T cells
Why is acute inflammation beneficial?
Causes vasodilation allowing for greater blood flow in the affected area – therefore higher recruitment of leukocytes
Fever is a byproduct of?
Inflammation
The recognition process in the adaptive immune response is known as the?
Clonal selection
What is clonal expansion?
Proliferation and differentiation B-cells and T cells
Define effector cells
Daughter cells of a specific B or T cell that recognize the same antigen
What is the average immune response time when encountered to a specific antigen for the first time?
Roughly 14 days
T/F: Immune response is faster when exposed to an antigen the second time
True
Why are immune responses faster the second time they are exposed to the same antigen?
Memory cells or immunological memory
Where are T cells produced? Where do they develop and mature?
Produced in bone marrow through the process of hematopoiesis
Develop and mature in the thymus
Where are B cells produced? Where do they mature?
Bone marrow
What are the two primary lymphoid tissues?
Bone marrow and thymus
T/F: antigens from pathogens are presented to lymphocytes in primary lymphoid tissue
False; presented in SECONDARY lymphoid tissue – lymph nodes
Where does lymphocyte activation primarily occur?
Lymph nodes
What connects the circulatory system to the lymphatic system?
Lymph nodes
Which lymphocyte is found in lymphoid follicles?
B cells
T/F: Effector cells migrate to lymphoid follicles to active B cells
True
Individuals without a _________ are more prone to _______________ bacterial infections.
Spleen; bloodborne
Where does antigen presentation and lymphocyte activation occur in the spleen?
White pulp
How do symbiotic microorganisms protect us from pathogen infections?
1) compete with pathogens for space and nutrients
2) microbiota can change environment such as lowering pH, impacting pathogenic survival
3) Production of antimicrobial agents to prevent colonization
Which immune are able to phagocytize pathogens?
1) Neutrophils
2) Eosinophils (not their primary function - low phagocytosis activity)
3) Macrophages
4) Dendritic cells
When does differentiation for a B cell occur?
When exposed to a foreign antigen
What are the three different types of agranulocytes of the immune system?
1) Lymphocytes – B and T cells
2) NK cells
3) ILCs
4) Monocytes which differentiate into dendritic cells and macrophages
Is the process whereby a lymphocyte expressing a specific cell surface receptor recognizes a foreign antigen
Clonal selection
Involves the activation of the clonally selected lymphocyte and its rapid division and differentiation into an effector cell
Clonal expansion
Which cell is responsible for immunological memory?
Memory cells
When are memory cells developed/produced?
During clonal expansion
Why is immunological memory important?
Allows our adaptive immune response to respond more quickly to a previously encountered antigen
In which lymphoid tissues do adaptive immune cells undergo clonal selection and expansion?
Secondary Lymphoid tissues
What process do neutrophils use to exit blood circulation?
Extravasion
