It is important to consider the route of entry, the size of venom components, their target sites and how they will reach them, how they will interact at the target site and their method and route of elimination in understanding what will happen when a human is envenomed.
Similar considerations occur for ingested poisonous animals.
Unfortunately, for many venoms and poisons, this depth of knowledge is not available. Nevertheless, adopting this concept of understanding will help in assessing the dynamic situations encountered with humans suffering from envenoming or poisoning. In general terms, at least for snake venoms, the larger components such as larger presynaptic neurotoxins and procoagulants should be too large to directly enter capillaries, so that they should travel via the lymphatic system to enter the circulation via the thoracic duct. There is some evidence to support this view for humans, with high concentrations of venom being found in draining lymph nodes at autopsy in fatal cases. Once in the circulation, some components will have found their target sites.