SB 2.10.31

tvak-carma-māṁsa-rudhira-
 medo-majjāsthi-dhātavaḥ
bhūmy-ap-tejomayāḥ sapta
 prāṇo vyomāmbu-vāyubhiḥ
Synonyms: 
tvak — the thin layer on the skin; carma — skin; māṁsa — flesh; rudhira — blood; medaḥ — fat; majjā — marrow; asthi — bone; dhātavaḥ — elements; bhūmi — earth; ap — water; tejaḥ — fire; mayāḥ — predominating; sapta — seven; prāṇaḥ — breathing air; vyoma — sky; ambu — water; vāyubhiḥ — by the air.
Translation: 
The seven elements of the body, namely the thin layer on the skin, the skin itself, the flesh, blood, fat, marrow and bone, are all made of earth, water and fire, whereas the life breath is produced by the sky, water and air.
Purport: 

The construction of the whole material world is prominently made by three elements, namely earth, water and fire. But the living force is produced by sky, air and water. So water is the common element in both the gross and subtle forms of all material creation, and it should be noted herewith that due to necessity, water, being most prominent in the material creation, is the principal element of all the five. This material body is thus an embodiment of the five elements, and the gross manifestation is perceived because of three, namely earth, water, and fire. Sensations of touch are perceived due to the thin layer on the skin, and bone is as good as hard stone. The breathing air of life is produced of sky, air and water, and therefore open air, regular bath and ample space in which to live are favorable for healthy vitality. Fresh produce from the earth like grains and vegetables, as well as fresh water and heat, is good for the upkeep of the gross body.