Cells And Tissues Flashcards
What are the most predominant type of granulocyte in the blood?
Neutrophils
What are neutrophils?
They are phagocytosis cells and are the most numerous component of the innate immune response
Where are neutrophils found?
At site of acute inflammation
Are eosinophils granulocytes?
Yes they are though to be important in defence against parasitic infections because their numbers increase during a parasitic infection
What reactions are eosinophils involved in?
They are involved in atopic reactions such as asthma
What do granules contain?
Basic proteins
What are basophils known as?
Granulocytes are found in relatively low numbers in normal blood
What is the function of basophils?
It is similar and complementary to that of eosinphils and mast cells
What do granules also contain?
Histamine, leuktrines, vasoactive mediators and platelet activating factors
What are macrophages?
They are major phagocytic cells which play a critical part in innate immunity
What is a monocyte?
A circulating cell which differentiates into a macrophage upon migration into the tissues
What are the two different forms of lymphocytes?
B cells and T cells
Describe B cells
Once activated B cells differentiate into antibody secreting plasma cells as part of the specific immune response
What are T cells?
They are thymus-matured lymphocytes
What are the two types of Thymus-matured lymphocytes?
Cytotoxic T lymphocytes and helper T lymphcytes
What do cytotoxic T cells do?
Kill virus infected cells
What do helper T cells do?
Activate other cells such as B cells and macrophages
What are natural killer cells (NK) cells?
Large, granular lymphocytes which form part of the innate immune response. Although lacking in antigen-specific receptors they can detect and attack some virus-infected cells
Where are mast cells found?
They are found across tissues mainly near the small blood vessels
What happens upon activation of mast cells?
They release substances from their granules that affect vascular permeability.
What do granules of the mast cells contain?
Histamine and heparin
What are mast cells known as?
They are known for their role in allergy. Also they are thought to play a part in protecting mucosal surfaces from pathogens
Where are all immune cell created?
They are created and matured in primary lymphoid tissues (the thymus and the bone marrow)
What are immune cells produced from?
They are produced from haemotopoietic stem cells
What happens to the immune cells once they have matured?
They leave the primary lymphoid tissues and enter the circulatory system
What can circulate between the non-lymphoid tissues and the secondary lymphoid tissue?
Lymphocytes and some mononuclear phagocytes - this increases the likelihood they will be exposed to pathogens picked up in tissues from all over the body
What fluid flows in lymphatic vessels?
Lymph fluid, the content is the same in interstitial fluid and the fluid around tissue cells
What does lymph do?
It drains interstitial fluids, transport dietary lipids and facilitates immune responses
What does lymph eventually drain into?
Venous blood
What are secondary lymphoid organs?
Lymph nodes, tonsils, spleen and mucosa associated lymphoid tissue (MALT)
Where are lymphocytes activated?
In the secondary lymphoids
