Whereas man and the rat are in the 'sinusal' group, the mouse belongs in the 'nonsinusal' group. The red pulp of spleens of rat, dog, man, and many other mammals contains an elaborate plexus of sinuses; that of mouse, cat, pig and others has no true sinuses and relatively few veins leading from the meshes into collecting veins - http://www.informatics.jax.org/greenbook/chapters/chapter13.shtml

wide vessels in the spleen that drain into trabecular veins[WP].

sinusoidal blood vessel of spleen

uberon

sinusoid of red pulp of spleen

UBERON:0003910

http://purl.obolibrary.org/obo/NCBITaxon_10088

http://purl.obolibrary.org/obo/NCBITaxon_9822

http://purl.obolibrary.org/obo/NCBITaxon_9681

http://purl.obolibrary.org/obo/NCBITaxon_10114