LIVER, NORMAL ANATOMY.—Syn. Gr.
wrap; Lat. jecur, berm ; Fran. foie ; Germ. Leber ; Ital. legato. The liver is a conglo merate gland of large size, appended to the alimentary canal, and performing the double office of separating certain impurities from the venous blood of the chylopoietic viscera, pre viously to its return into the general circulation, and of secreting a fluid necessary to digestion— the bile.
It is situated in the abdomen, in the right hypochondriac region, and extends across the epigastrium into the left hypochondriac region. Superiorly it ascends to a level with the sixth or seventh rib, diminishing the cavity of the chest on the right side, and inferiorly it ap proaches by its anterior border, the lower mar gin of the thorax.
The general firm of the liver is flattened, being broad and thick towards the right ex tremity, and narrow and thin towards the left. Glisson compared its shape to the segment of an ovoid cut obliquely in the direction of its length, and Dr. Alexander Alonro to the hoof of an ox rounded superiorly. Its superior surface is convex ; the inferior irregularly con cave ; the posterior border is thick and rounded, and the anterior thin and sharp.
Its position in the abdomen is oblique, the convex surface, in the erect posture of the body, being directed upwards and forwards, and the concave downwards and backwards. The broad border is posterior and superior, and the thin margin anterior and inferior. If the trunk be inclined forwards the free edge of the liver may be felt, extending below the margin of the thorax.
It is in relation by its convex surface, su periorly with the diaphragm, which separates it from the under surface of the right lung and from the heart ; anteriorly with the diaphragm and transversalis muscle, and with the sheath of the rectus and linea alba at the epigastrium ; and on the right side with the diaphragm and transversalis muscle, which are interposed be tween it and the seven or eight lower ribs. Its iillerior or concave surface. is in relation with the anterior aspect of the stomach, the ascending portion of the duodenum, the trans verse colon, the right supra-renal capsule, and the right kidney, and sometimes by its left extremity with the upper end of the spleen. The posterior border rests against the dia phragm, which intervenes between it and the vertebral column, and is in contact with the inferior vena cava, (esophagus, and right pneu mogastrie nerve. The anterior border is free
and in relation with the transversalis muscle, which separates it from the cartilages of the lower ribs,' with the round ligament at the notch, and with the sheath of the rectus anal linea alba at the epigastrium.
The liver is retained in its place by duplica tures of peritoneum which pass between its convex surface and posterior border and the diaphragm, and by a fibrous cord which crosses from the linea alba to the inferior veils cava. These are the ligaments of the liver ; they are five in number, the broad, the two lateral, the coronary, and the round ligament.
The broad ligament, (fig. 32, 7) (litici form, longitudinal, I. latum, I. suspensorium hepatis) is an antero-posterior duplicature of peritoneum which extends from the notch on the anterior margin of the liver to the superior part of its posterior border. It is broad in front where it incloses the round ligament, and becomes narrow as it passes backwards; hence its synonym, j'aleifbrm. It serves to connect the convex surface of the liver with the linea alba and diaphragm.
The lateral ligaments (fig. 32, 8, 9) (triangular) are two triangular folds of peri toneum which commence at each extremity of the posterior border of the liver and converge towards the termination of the broad ligament. They are broad near the extremities of the or gan, and permit of a certain degree of motion in the right and left lobes, but become narrow as they approach the middle line. The two layers which compose the right lateral ligament separate as they pass inwards, and partly inclose an oval space (11, 11) of variable size, which is uncovered by peritoneum and in close con tact with the diaphragm ; the remainder of the space is bounded by the division of the layers of the broad and left lateral ligaments. The peritoneum surrounding this space, with the contained cellular tissue, which is large in quan tity and connects the posterior border of the liver firmly with the right leaflet of the central tendon of the diaphragm, constitutes the co ronary ligament. The inferior vena cava (14) emerges from the liver at about the middle of this space previously to its passage through the quadrilateral opening in the tendon of the dia phragm. The left lateral ligament, near to its extremity, advances a little upon the upper sur face of the left lobe.