Umongo obomvu ufunyanwa kumathambo a-flat kuphela - njengakwithambo lesinqa, kwithambo lesifuba, elentloko, iimbambo, kwizilwanyana ezinethambo lomqolo (amathambo athi xa edibene enze i-spinal column), nasemagxeni - nakumathambo enziwe nge-cancellous (""antofontofo"") ekupheleni kwamathambo amade anje nge-femur (ithambo lethanga) kunye ne-humerus (ithambo elikumntla nelisisandulela sengalo). Umongo oqanda wona ufunyanwa ngaphakathi kwindawo ezivulekilyo kanye kumbindi wethambo, okanye kwisikhewu se-medullar esifumaneka kumathambo amade.