Circulatory System 12 PLEASE DO NOT MOVE THE FIELD!

This is from an alternative copy of slide H24. It shows a portion of the red pulp in a thin plastic section of the spleen. The "L" is in the lumen of a sinusoidal capillary (venous sinusoid) whose lumen is much larger than that of a "standard" capillary. Furthermore, such capillaries are discontinuous; that is their endothelial lining has numerous large gaps between adjacent endothelial cells (the nuclei of two endothelial cells are labeled "N"). It is through such "gaps" that cells pass between the lumen of the vessel and the surrounding connective tissue. For example, at the "1" a nucleated cell is traversing such a gap, while at "2", an erythrocyte is; in neither case is it possible to tell the direction of the movement.

Slide K-12, field J12 (lower left) of finder slide A, 40X objective.