Immune System Flashcards
What does the immune system ensure?
harmful pathogens don’t enter
What is the innate system?
for broad, general responses
in all animals
What is the adaptive system?
for specific responses
in vertebrates only
What is molecular recognition?
identification of non-self molecules elements via binding to Immune Receptors that have 3d shape that matches a corresponding pathogen, lock and key fit
What does innate immunity include?
non-specific barrier defenses
What are barrier defenses?
layers setup non-specific, physical barrier to pathogen entry like skin or exoskeletons
What is the purpose of the mucous membrane/secretions?
create fluid that traps and washes away pathogens
What are lysozyme?
general digestive enzymes in tears, saliva, mucus
What do general receptors detect?
broad pathogen patterns
How do some invertebrates kill viruses?
through RNA interference
What are phagocytes?
engulf pathogens in amoeba-like fashion
What are neutrophils?
a type of phagocyte that circulates within blood vessels
What are macrophages?
present in all tissues; some migrate
What are dendritic cells?
often in tissues that contact the environment that will engulf pathogens, break them up, and present parts of the pathogen (antigen) on the cell membrane
What does antigen presentation activate?
activates the adaptive immune system
What are natural killer cells?
detect abnormal proteins in infected/cancer cells and dock to the bad cell
the release proteins that form pores in the cell and invade with water to lyse the cell
What are microbial peptides?
they disrupt membrane integrity in bacteria
What are interferons?
secreted by an infected host cell, which activates inhibits of viral replication in neighbor cells
What is the inflammatory response?
part of innate immunity that is triggered by physical injury or infection
What are mast cells?
immune detector cells that release chemical histamine
What is histamine?
attracts neutrophils and widens capillaries (inflammation)
What does the adaptive immunity do?
has specific receptors that detect unique pathogen parts
gives high specificity
What are lymphocytes?
white blood cells bade in bone marrow
What are T-Cells?
migrate to thymus for storage and maintenance
What are B-Cells?
stay in bone marrow for storage and maintenance
What do T and B cells present?
express antibodies that are unique antigen receptors
What are the variable regions?
different in each antibody
give each antibody a unique antigen binding ability
What are the constant regions?
same in all antibodies
What are Immunoglobulin Genes?
encode antibody chains that undergo internal recombination
What is recombinase?
an enzyme that randomly links one J with one V, deleting DNA in between, creating a unique gene for each precursor cell
What leads to autoimmune disorders?
antibodies target the body’s own tissue and leave the bone marrow where they should’ve been kept and destroyed, but genomic disorder prevents this
How are B and T cells patrolled?
through the circulatory system and lymphatic system
Where do pathogens collect?
lymph nodes
What happens when an antibody from an unique B cell finds a matching antigen?
It triggers cell division to produce more this specific B-Cell/antibody type
Massive production of soluble form of this type of antibody, via plasma cells
formation of long-lived memory cells that can be quickly made if re-infection occurs
How doe antibodies work to kill pathogens?
Neutralization: antibodies flood surface of pathogen so it cannot interact with cells in the host
opsonization: makes pathogens more easily found in phagocytes
recruitment: whether through direct B cell interaction or via opsonization, antibodies bring antigen to helper t cells
How are helper T cells activated?
by interacting with another cell that is presenting antigen on the surface of a cell with the appropriate MHC complex
What is Humoral immunity?
secretion of antibodies into blood plasma to fight pathogens in body fluids
What is cell-mediated immunity?
attack and destroy host cells that have already been infected
