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,
Theology of the Body of love... [or] communion of persons"" but rather is a mere bodily union. On the other hand, the licitness of natural family planning (NFP) methods is held to be evident from the structure of the human body, which has natural periods of fertility and infertility. The morality of these methods was literally designed into the body, and use of them, unlike use of artificial contraception, can actually improve the dialog between couples which is expressed through the language of the body. Throughout these speeches the main emphasis is on the intrinsic "goodness" of the marital act. The power of love