Changes

#* Once the gaps are big enough [[Erythrocytes|Erythrocytes]] can migrate through the gaps in the altered endothelium to the damaged tissue.

#* Once the gaps are big enough [[Erythrocytes|Erythrocytes]] can migrate through the gaps in the altered endothelium to the damaged tissue.

# '''Induction of an increase in temperature'''

# '''Induction of an increase in temperature'''

#* This rise in temperature may occur either locally or systemically. A systemic rise in temperature is known as pyrexia. Occurs in general acute inflammation, and is often a sign of infection. To raise the body temperature, pyrogens are released which act on the temperature control centres in the hypothalamus, and are released from[[Macrophages|macrophages]] in particular, but also [[Neutrophils|Neutrophils]] and [[Eosinophils|eosinophils]]. Again, the [[Cytokines|cytokines]] TNF-α, Il-1 and IL-6 are all important in producing this pyrogenic response. These are termed '''endogenous pyrogens''' as they are endogenous to the body and not from an external source. Other pyrogens include the cellular coat of gram-negative organisms, the necrosis of damaged tissue cells, antigen-antibody complexes, and tumours (particularly those which have metastasised though it may be difficult to separate this from the pyrexia caused by the central necrosis in such tumours).

#* This rise in temperature may occur either locally or systemically. A systemic rise in temperature is known as pyrexia. Occurs in general acute inflammation, and is often a sign of infection. To raise the body temperature, pyrogens are released which act on the temperature control centres in the hypothalamus, and are released from [[Macrophages|macrophages]] in particular, but also [[Neutrophils|Neutrophils]] and [[Eosinophils|eosinophils]]. Again, the [[Cytokines|cytokines]] TNF-α, Il-1 and IL-6 are all important in producing this pyrogenic response. These are termed '''endogenous pyrogens''' as they are endogenous to the body and not from an external source. Other pyrogens include the cellular coat of gram-negative organisms, the necrosis of damaged tissue cells, antigen-antibody complexes, and tumours (particularly those which have metastasised though it may be difficult to separate this from the pyrexia caused by the central necrosis in such tumours).

==Cells==

==Cells==