IMMUNITY Flashcards
Define Immunity
immunity is the resistance to infectious disease.
What are the type of cells which provide defence against infection?
WBC, which are also known as leukocytes
Where are WBC created?
derived from stem cells in own barrow
What does the lymphatic system consist of?
lymphatic vessels, and lymph nodes
Where do B cells and c cells originate ?
b- born marrow
t- thymus
What occurs in the lymph nodes?
lymph nodes are the sites where any new foreign antigen meet and activate B cells and T cells. where immune response occurs
What are the two main sub divisions of immune system?
- innate and adaptive
What are the main differenced between the innate immunity and adaptive immunity ?
- specificity of response
- pathogens it responds to
- whether it is developed of innate
- major responses
What are the three divisions of the immune system?
1st line- physical, chemical and flora barriers
2nd line- live actions, cells of immune system, soluble proteins, that mounts a rapid non-specific attack against pathogens
3rd line- actions of immune cells ad antibodies specifically tailored to pathogen.
When is the 3rd line of defence activated?
the adaptive immune system only comes into operation only if the second line of defence fails.
What are the major barriers of the first line of defence ?
- Intact skin
- Mucous membrane and their secretions
- presence of normal flora
How does intact skin act as a defence barrier?
constitutes an important physical and chemical barrier to microbial infections.
the constant shedding of dead surface cells is an effective barrier against pathogens
sebaceous glands in the skin produce sebum= protective antimicrobial film on the skin
How does mucous membrane and their secretions act as a defence barrier?
is the interspace of the airways, gut and urogenital tract are lined with mucous membrane consisting of ethical cells. adjacent cells have tight junctions which prevent entry of microbes
airways recreate mucous which traps entering pathogens, and the cilia moves the mucus up and out
How does flora at as a defence barrier?
flora is a non-pathogenic bacteria that are normal residents in specific areas of the body, inhibits growth of pathogenic microbes
What is the 2nd line of defence?
2nd line of defence involves the actions of immune cells and soluble proteins that produce inflammation
what is inflammation?
localised protective repose to infection
What are the main phagocytic cells in the innate immune system?
neutrophils, macrophages and dendritic cells.
Define phagocytosis
bulk engulfment of solid material into cells