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 dominating all subordinate material instincts, becomes similar to God. This similarity must be goal of all human undertaking. Gregory of Nazianzus (330-390) contemplated on the origin of the human body. Man was created by God with body and soul, a visible and invisible part, like the angels. He was created to praise God like they did. The body was given to man, so he may suffer and eventually die, and thus not consider himself to be God. The material essence of the body separates us from God, like a cloud, or, as Gregory stated, like the cloud between the Egyptians