--subdivision Histology under individual animals and groups of animals, and under individual organs and regions of the body, e.g. Fishes--Histology; Heart--Histology
--subdivision Physiological aspects under activities and mental conditions for works on the relationship between an individual's activity or mental state and his physiology, e.g. Soccer--Physiological aspects; Mental illness--Physiological aspects; also subdivision Physiological effect under individual chemicals and groups of chemicals and under environmental phenomena or conditions for works on their effect on the functions of living organisms, e.g. Copper--Physiological effect; Heat--Physiological effect; and subdivision Physiology under individual animals and groups of animals, organs and regions of the body, classes of persons, and ethnic groups, e.g. Fishes--Physiology; Heart--Physiology