Human body of different cavities, separated areas which house different organ systems. The brain and central nervous system reside in an area protected from the rest of the body by the blood brain barrier. The lungs sit in the pleural cavity. The intestines, liver, and spleen sit in the abdominal cavity Height, weight, shape and other body proportions vary individually and with age and sex. Body shape is influenced by the distribution of muscle and fat tissue. Human physiology is the study of how the human body functions. This includes the mechanical, physical, bioelectrical, and biochemical functions of humans in good health,
Catholic theology of the body God in his image. This is considered important even today, as the existence of a soul is the basis for much Church teachings on the human body, in areas such as abortion. Ambrose of Milan and Augustine of Hippo applied these views in their teachings on the human body, virginity and celibacy. Thomas Aquinas developed a systematic view, which dominated Church teachings and ecumenical councils including Vatican II. All recent popes contributed from different angles to the theology of the body. Current issues include the dignity of the body in light of its divine origin and destination, its eventual resurrection;