infection and immunity Flashcards
Define the immune system
“The human body is constantly engaged in a bitter internal war against vast armies of microscopic enemies … Thankfully for us, we are equipped with an internal defence mechanism designed to combat these threats … [whose] purpose is remarkably simple: to recognize, disable and dispose of all intruders – and then to remember them, in case they return at a later date”
The Immune System: In Defence of Our Lives. Nobelprize.org. Nobel Media AB, 2014)
What is the difference between Innate and adaptive immunity?
Innate:
Innate response cells act the same way for the any pathogen
Generally stimulate the inflammatory response
Some innate cells stimulate the adaptive/specific response by:
Phagocytosis: Digesting the pathogen and ‘spitting’ it out
Antigen Presentation: Displaying ‘bits’ of a pathogen to stimulate adaptive response
Chemical Mediator Secretion: Simulates adaptive cells to respond
Adaptive: When the innate response is un
What are neutrophils?
Neutrophilsare a major component of the white blood cell count.
Their role is in innate immunity where they play a key role in acute inflammation.
Neutrophils are recruited from the blood to the site of infection and are phagocytic
Describe phagocytosis
Describe the stages of phagocytosis –
The phagocytic cell is attracted to the pathogen by chemotaxis (chemical attraction resulting in movement)
The cell membrane changes to form pseudopods (arms) around the pathogen surrounding it
The cell membrane encases the pathogen as it enters the cell forming a phagosome
Lysosomes containing digestive chemicals and enzymes merge with the phagosome causing a phagolysosome
Breakdown of the pathogen occurs causing fragments of biological matter
The biological matter is excreted by exocytosis; and contribute to further processes:
Antigen Presentation
Recruitment of further inflammatory and immune responses
Removal by the lymphatic system causing T/B Cell Production
What are monocytes?
Monocytesare a minor component of the white blood cell count. Monocytes quickly enter the tissues of the body where they develop into macrophages.
What are Macrophages?
Macrophagesare a mature form of monocytes that have migrated into the tissues.
Macrophages are present in almost all tissues of the body. Macrophages play a role in both the innate and adaptive immune responses.
They are phagocytic and secrete cytokines which trigger inflammation and activate other immune cells.
Macrophages also clear dead cells and cell debris in their role in healing damaged tissues.
However, macrophages produce much of the tissue damage occurring in chronic inflammation.
What are Basophils and Eosinophils?
Basophils and eosinophilsdefend against parasitic worms and ticks which are too large to be engulfed by neutrophils or macrophages.
They are involved in allergy.
They form only a minor component of the white blood cell count.
What’s the mast cell?
Mast cellsare found in many tissues of the body, especially just beneath epithelial surfaces of the skin and mucosa.
Like basophils and eosinophils, mast cells have a role in immunity against parasites.
They contain granules of histamine.
Mast cells are involved in acute inflammation and allergy.
What are the dendritic cells?
Dendritic cellsare present in the tissues and lymph nodes.
Dendritic cells ‘display’ or ‘present’ fragments of the microorganisms on their surface. This display helps to adaptive immune cells
As noted above, fragments of a microorganism are antigens, and for this reason dendritic cells are called antigen-presenting cells.
What are the 5 features of inflamation
Heat. Redness. Swelling. Pain. Loss of function
Whats is Calor?
Heat
What is Latin for loss of function?
What is dolor?
pain
What is rubor?
redness
what is tumor? (latin)
swelling
