Physical environment: health care, health behaviors, *learning catalytics- which of the following is a major pathway or mechanism by which. Sdoh exert their influence on health: stress, there are multiple pathways- genetics, environmental conditions, etc, review: common pathway for sdoh: chronic stress but stress is a common pathway for many things, decreased immune function. Importance to ph: vulnerable populations: deserve special protection, more resources should be devoted to reaching & serving these groups. Elimination of existing or potential inequities: example. Infant mortality is the death of an infant before his or her first birthday. The infant mortality rate is the number of infant deaths for every 1,000 live births. In addition to giving us key information about maternal and infant health, the infant mortality rate is an important marker of the overall health of a society: over 23,000 infants died in the united states in 2015.