Veins between two capillary networks are portal systems. Closed circulatory system, but fluid constituents of blood leak out of capillaries and return to the heart by the second component of the ...

Start with dorsal aorta, formed by 4 pairs of efferent branchial arteries. Within the pleuroperitoneal cavity, it gives off a series of abdominal branches. Locate each of the paired and unpaired ...