Immunity (4th LE) Flashcards
Cells, tissue, and molecule that fight against infections
Immune System
Study of structure and function of the immune system
Immunology
Ability of organism to resist infection
Ability of organism to eliminate potentially harmful or abnormal cells
Immunity
Collective and coordinated response against infecttion or introduction of foreign substances in a host, by the cells and molecules of the immune system
Immune Response
Role of Immune System
Defense against microbes Defense against growth of tumor cells Rejection of foreign cells Homeostasis Inappropriate responses
Destruction of abnormal or dead cells through
Homeostasis
Examples of abnormal or dead cells
Dead red or white blood cells
Antigen-antibody complex
Examples of inappropriate responses
Allergies
Autoimmune diseases
Immune System
Organs
Cells
Molecules
Immune System Organs
Tonsils Skin Bone marrow Bloodstream Thymus Lymphatic system Spleen Mucosal tissue Payer's patches
Immune System Cells
Lymphocytes
Monocytes, Macrophage
Granulocytes
Examples fo Lymphocytes
T-lymphocytes
B-lymphocytes, plasma cells
Natural killer lymphocytes
Examples of granulocytes
Nuetrophils
Eosinophils
Basophils
Immune System Molecules
Antibodies Complement Cytokines Interleukins Interferons
Two types of immunity
Innate (non-adaptive)
Acquired (adaptive)
First line of defense Non-specific resistance Inborn (based on gene) No memory Dependent on phagocytes Quick response
Innate Immunity
Second line of defense Specific resistance Antigen specific Developed memory Handled by T and B lymphoctes Slow response
Acquired Immunity
Organisms with innate immunity
All animals
Barrier defenses of innate immunity
Skin
Mucous membranes
Secretions
Internal defenses of innate immunity
Phagocytic cells
Natural killer cells
Antimicrobial proteins
Inflammatory response
Organisms with adaptive immunity
Vertebrates only
Antibodies defend against infection in body fluids
Humoral response
Cytotoxic cells defend agaisnt infection in body cells
Cell-mediated response
First line of defense (innate)
Skin
Mucous membranes
Secretions of skin and mucous membranes
Second line of defense (innate)
Phagocytic leukocytes
Antimicrobial proteins
Inflammatory response
Fever
Third line of defense (adaptive)
Lymphocytes
Antibodies
Memory cells
Under innate immune system
External defenses
Internal defenses
Innate immune system
Prevent microbial entry
Detect invaders
Eliminate threat
External defenses of innate immune system
Physical barriers
Chemical barriers
Biological factors
Internal defenses of innate immune system
Cellular mechanisms (eg WBC)
Physical Barriers
Skin
Sebaceous glands in skin
Mucosal tissues/surfaces
Flushing action of saliva, tears, and urine
Chemical Barriers
Antimicrobial peptides in sweat
Gastric acid in stomach
Lysozyme in tears/saliva
Defensins
Biological Factors
Normal Microbiota
Non-pathogenic, harmless bacteria
Normal microbiota
Ratio of human cells and normal microbiota in our body
1:10
Possible sources of normal microbiota in a newborn
Passage through birth canal Feeding materials Instruments Other people Nursing
Bacteria in the large intestines are responsible for:
Gases
Odors
Normal Microbiota functions
Excludes pathogens by: - Preventing adherence - Consuming nutrients - Producing toxins Stimulates host immune system
Some body parts are naturally sterile such as:
Internal organs
Blood
Lymph system
Nervous system
Internal defenses
Second line of defense
Where majority of immune tespinse cells are found
Blood
Blood composition
55% plasma
1% WBC and platelets
44% RBC
Plasma also contains
Complement proteins
Coagulation protein
Cytokines
Cells for 2nd and 3rd line defences
Leukocytes (WBC)
Leukocytes pass from blood to interstitial spaces process
Extravasation (or diapedesis)
Large phagocytes found in blood
Monocytes
Function of monocytes
Phagocytosis
Serves as Antigen-Presenting Cells (APC)
Engulf, process, and present antigens to lymphocytes to initiate adaptive immune response
APC
APC derivatives
Macrophages
Dendritic Cells
First defensice cells that interact with pathogen
Chief phagocytic cell
Ingest and destroy pathogens
Macrophages
Where can macrophages be found?
Found in tissue
Abundant in spleen and lymph nodes
Communicates with T lymphocytes by collecting antigens from the tissues and then bring them to lymphocytes
Promotes immune response
Dendritic Cells
Where can dendritic cells be found?
Abundant along epithelial linings, skin, and mucous membranes
Second lineage of defense after monocytes
Contains granules
Granulocytes
Granulocytes include
Neutrophils
Basophils
Eosinophils
Mast cells
Common phagocyte but not APC
Die after phagocytosis
Found in bloodstream and bone marrow
Nuetrophils
Initiate an inflammatory response
Responsible for some allergic reactions
Release histamines
Mast Cells
Against helminth parasitic infection, an allergic reaction or cancer
Eosinophils
Production of acute inflammation
Synthsize and store heparin and histamine
Basophil
Cytotoxic lymphocytes, not a B nor a T lymphocytes
Recognize and kill compromised cells
Natural Killer Cells
Forms a pore in target cells for granzymes to enter
Perforin
Cytotoxins that caused apoptosis or programmed cell death
Granzymes
Specific surface molecules that are present in most healthy cells
Major histocompatibility complex (MHC)
Specialized leukocytes from lymphoid precursor cells
Lymphocytes
3 types of Lymphocytes
B cells
T cells
Natural killer cells
Specialized APC
Part of adaptive immunity
B cells
Almost similar with B cells - adaptive immunity
T cells
Part of innate immunity
Natural killer cells
Soluble proteins that interact with specific antigens
Antibodies (immunoglobulins)
