(In case you need visuals)
This picture shows the interstitial fluid. Basically just the area outside the blood vessel -
https://textimgs.s3.amazonaws.com/osanp/m46411/2702_Fluid_Compartments_ICF_ECF.jpg
This picture shows the relationship between blood vessels and lymph -
Histamine causes endothelial contraction, this increases vascular permeability and leakage of protein-rich fluid from the postcapillary venules into the interstitial space -> increases interstitial oncotic pressure. (choice C).
Due to this it also increases capillary filtration rate, because the endothelial contracts. (choice A)
Because there is more fluid in the interstitial space, there is more lymph flow. (choice E).
FA19, pg 213
Histamine plays a major role in the cardinal signs of inflammation. It helps mediate vasodilation and vascular permeability (via endothelial cell contraction). These two functions are already contrary to A, B, C, and D. By increasing fluid in the interstitial space, you can reason that there will be increased lymph flow.
There is "a direct action of histamine on the lymphatic smooth muscle via stimulation of H1 (and in some vessels H2) receptors. H1 receptors enhance and H2 receptors slow down lymphatic pumping, the dominant effect being an increased contractile activity."
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1573448/
"Lymphatic vessels adapt their pumping activity to changes in fluid load. This function is particularly important during inflammatory reactions where the increase in vascular permeability and resultant elevation in interstitial fluid and protein concentration give rise to oedema that must be offset by an appropriate rise in lymph flow."
The article is saying that in an inflammatory response, histamine increases the vascular permeability, and blood will move from the capillaries into the interstitial space. To maintain fluid balance and prevent edema, the lymphatic system will respond with increased lymphatic flow back into blood vessels to offset the increased fluid flow into the interstitial space. That is why there is increased lymph flow.
submitted by โnor16(70)
Histamine increases microvascular permeability, i.e. Fluid + Proteins, this increases pressure in the interstitium > lymph flow increases