Infection proliferates and disseminates rapidly and so innate immunity should react effectively and fast. Innate immunity mechanisms depend upon fluid dynamics and are different in compartments with slow (the tissues) and rapid (the bloodstream) liquid flow. In the tissues, coagulation initiated by clotting factors, platelets and erythrocytes, is prompt and effective mechanism of the first line of antibacterial defense. Resident macrophages, transmigrated neutrophils, monocytes, NETs and platelets are the second line of the defense. In the bloodstream the first line of innate immunity defense are erythrocytes that kill pathogens by oxygen, released from oxyhemoglobin (oxycytosis); the second line of the defense is coagulation that in case of overactivation may cause disseminated intravascular coagulation (DIC). Blood coagulation is the fastest mechanism of infection confinement and inactivation. It is the first and the last line of innate immunity defense and occurs both in the tissues and the bloodstream.

感染迅速扩散和传播，因此先天免疫应迅速有效地反应。先天免疫机制取决于流体动力学，并且在液体流动缓慢（组织）和液体流动迅速（血液）的隔室中是不同的。在组织中，由凝血因子，血小板和红细胞引发的凝血是抗菌防御第一线的迅速而有效的机制。驻留巨噬细胞，中性粒细胞迁移，单核细胞，NET和血小板是防御的第二道防线。在血液中，先天免疫防御的第一线是红细胞，它通过从氧合血红蛋白释放的氧杀死病原体（氧合作用）。防御的第二道防线是凝血，如果过度激活，则可能导致弥散性血管内凝血（DIC）。凝血是感染限制和灭活的最快机制。它是先天免疫防御的第一行和最后一行，同时发生在组织和血液中。