bdaminal

[ABDOMEN.] Belonging to the abdomen. "... the size of the abdominal cavity."-Todd and Bowman: Physiol. Anat., vol. ii., p. 266. Abdominal regions: Certain regions on the external surface of the abdomen formed by the tracing upon it of imaginary lines. A line is drawn horizontally from the extremity of the last rib on one side to the same point on the other. A second line is then drawn parallel to the first between the two anterior superior proce es of the ilium. These two lines nece arily divide the abdomen into three horizontal bands or zones. The first or highest one is called the epigastrium (EPIGASTRIUM]; the second or middle one, the umbilical region [UMBILICAL]; and the third or lowest the hypogastrium [HYPOGASTRIUM]. Two vertical lines are then drawn on either side from the cartilage of the seventh rib downward to the anterior superior spine of the ilium. These nece arily intersect the three horizontal zones, dividing each of them into three parts so as to make nine in all. The central division of the epigastrium constitutes the epigastric region, properly so called, on either side of which lie the right and left hypochondria [HYPOCHONDRIA). The central portion of the umbilical region is the umbilical region properly so called; whilst the compartments on either side are named the right and left lumbar regions. The hypogastric region is similarly divided into three, the central called the pelvic region, and the two side ones the right and left iliac regions. Abdominal ring or inguinal ring : One of two oblong tendinous openings or "rings" existing in either groin. Through these rings pa the spermatic cord in the one sex, and the circular ligament of the uterus in the other. The aponeurotic fibres which form the immediate boundaries of the two openings are called the pillars of the ring. One of these is superior, internal or anterior, and the other inferior, external and posterior. 3 5 2 10 IMG:content-0017.png:[blocks in formation] being attached to the humeral bone. It is the most numerous in species of the soft finned orders, and contains the greater number of the fresh-water fishes. It is divided into five families: the Cyprinidæ, or Carps; the Esocidæ, or Pikes; the Siluridæ, or Siluri; the Salmonidæ, or Salmon; and the Clupeidæ, or Herrings. [MALACOPTERYGII.]