Capitulum of the humerus the distal end. In non-avian archosaurs, including crocodiles, the capitellum and the trochlea are no longer bordered by distinct etc.- and entepicondyles respectively, and the distal humerus consists two gently expanded condyles, one lateral and one medial, separated by a shallow groove and a supinator process. Romer (1976) homologizes the capitellum in Archosauromorphs with the groove separating the medial and lateral condyles. In birds, where forelimb anatomy has an adaptation for flight, its functional if not ontogenetic equivalent is the dorsal condyle of the humerus. Capitulum of the humerus In human anatomy of the arm, the capitulum of the humerus
Bone marrow Bone marrow Bone marrow is a semi-solid tissue which may be found within the spongy or cancellous portions of bones. In birds and mammals, bone marrow is the primary site of new blood cell production or hematopoiesis. It is composed of hematopoietic cells, marrow adipose tissue, and supportive stromal cells. In adult humans, bone marrow is primarily located in the ribs, vertebrae, sternum, and bones of the pelvis. On average, bone marrow constitutes 4% of the total body mass of humans; in an adult having 65 kilograms of mass (143 lb), bone marrow typically accounts for approximately . Human marrow