Changes

<p>Eosinophils are mainly located in connective tissue associated with routes into the animal i.e. [[Cardiorespiratory System - Anatomy & Physiology#Upper Respiratory Tract|respiratory]], [[Alimentary - Anatomy & Physiology|alimentary]], [[Urinary System - Anatomy & Physiology|uro]][[Reproductive System - Anatomy & Physiology|gential]] systems. They play key roles in reacting to [[Parasites|parasites]] and allergens but have limited phagocytic ability and therefore play no role in bacterial infections.</p>

<p>Eosinophils are mainly located in connective tissue associated with routes into the animal i.e. [[Cardiorespiratory System - Anatomy & Physiology#Upper Respiratory Tract|respiratory]], [[Alimentary - Anatomy & Physiology|alimentary]], [[Urinary System - Anatomy & Physiology|uro]][[Reproductive System - Anatomy & Physiology|gential]] systems. They play key roles in reacting to [[Parasites|parasites]] and allergens but have limited phagocytic ability and therefore play no role in bacterial infections.</p>

==Development==

==Development==

<p>The eosinophil is a [[Granulocyte - WikiBlood|granulocyte]] and has a similar development to the other [[Granulocyte - WikiBlood|granulocytes]]. This process is called [[Leukopoiesis - WikiBlood#Granulopoiesis|granulopoiesis]] and further details can be found [[Leukopoiesis - WikiBlood#Eosinophils|here]]. Eosinophils are more prominent in some species than others, notably in the pig and the horse.</p>

<p>The eosinophil is a [[Granulocyte - WikiBlood|granulocyte]] and has a similar development to the other [[Granulocyte - WikiBlood|granulocytes]]. This process is called [[Leukopoiesis#Granulopoiesis|granulopoiesis]] and further details can be found [[Leukopoiesis#Eosinophils|here]]. Eosinophils are more prominent in some species than others, notably in the pig and the horse.</p>

==Granules==

==Granules==

==Actions==

==Actions==

<p>Eosinophils are involved in [[Type I Hypersensitivity - WikiBlood|type I hypersensitivity]] reactions.</p>

<p>Eosinophils are involved in [[Type I Hypersensitivity - WikiBlood|type I hypersensitivity]] reactions.</p>

<p>In an infection or allergic reaction, eosinophil numbers are increased by the release of Il-3, Il-5 and GM-CSF (see [[Leukopoiesis - WikiBlood#Summary of pathways|eosinophil development]]) by Th2 and  [[Mast Cells|mast cells]]. This causes more eosinophils to be released into the blood stream. The eosinophils are then attracted to the required site of action by chemicals known as eotaxins which are released by mast cells. Histamine and its breakdown products also act as attractants. These same products activate the eosinophil increasing its affinity to bind to IgE.</p>

<p>In an infection or allergic reaction, eosinophil numbers are increased by the release of Il-3, Il-5 and GM-CSF (see [[Leukopoiesis#Summary of pathways|eosinophil development]]) by Th2 and  [[Mast Cells|mast cells]]. This causes more eosinophils to be released into the blood stream. The eosinophils are then attracted to the required site of action by chemicals known as eotaxins which are released by mast cells. Histamine and its breakdown products also act as attractants. These same products activate the eosinophil increasing its affinity to bind to IgE.</p>

<p>Large numbers of eosinophils in a tissue give the tissue a greenish colour.</p>

<p>Large numbers of eosinophils in a tissue give the tissue a greenish colour.</p>

===Anti-parasitic===

===Anti-parasitic===