Small Intestine

The coils of the small intestine lie mainly in the umbilical and hypogastric regions.

Large Intestine

The caecum, which is in the right iliac region, is in contact with the anterior abdominal wall just above the outer third of Poupart's ligament; its position otherwise varies according to its dilatation; when empty, it is generally covered by coils of small intestine. The orifice of the appendix is opposite "McBurney's point," located on the surface at the junction of the upper and middle thirds of a line drawn from the umbilicus to the right anterior superior iliac spine.

The ascending colon lies deeply in the right lumbar region upon the quadratus lumborum and the right kidney.

The hepatic flexure lies immediately to the right of the gallbladder beneath the tenth costal cartilage.

The transverse colon crosses the upper part of the umbilical region; it forms a U-shaped loop which reaches for a variable distance below the umbilicus; when the intestines are distended it may ascend in front of the stomach.

The splenic flexure reaches upwards behind the stomach, and touches the lower extremity of the spleen.

The descending colon lies deeply in the left lumbar region.

The iliac and pelvic portions of the colon lie in the left iliac fossa and true pelvis respectively.

The Kidneys

Unless enlarged or displaced, the kidneys can seldom be felt through the abdominal wall. The right kidney as a rule lies a little lower than the left, and a little further from the mid-line. For practical purposes the hilum of the kidney may be regarded as opposite a point 1/2 inch internal to the tip of the ninth costal cartilage ; and a line joining the two hili is in the transpyloric plane.

The Abdominal Aorta

The abdominal aorta commences about 1 inch above the transpyloric plane, and bifurcates a little to the left of the nid-line on a level with the highest part of the iliac crest, generally about 3/4 inch below the umbilicus, opposite the fourth lumbar vertebra.

The Back.

In the middle line of the back is the spinal furrow, along which the spines of the vertebrae can be easily palpated, becoming more distinct when the spine is flexed.

The spine of the first dorsal vertebra is more prominent than that of the vertebra prominens (seventh cervical), the third dorsal is on a level with the root of the spine of the scapula, the seventh dorsal with its inferior angle, the fourth lumbar with the highest part of the iliac crest, and the second sacral with the posterior superior iliac spine.

Over the upper sacral region is a flattened triangular area, the angles of which correspond with the posterior superior iliac spines and the third sacral vertebra.

Above the spine of the scapula is the suprascapular region ; the levator anguli scapulae and trapezius muscles can easily be seen by shrugging the shoulders. The lower border of the trapezius is indicated by a line from the twelfth dorsal spine to the root of the spine of the scapula.

The upper border of the latissimus dorsi is indicated by a line extending outwards from the sixth dorsal spine across the angle of the scapula.

The outer border of the erector spinae is indicated by drawing a line from a point on the iliac crest 3 1/2 inches from the mid-line upwards and outwards to the angles of the ribs. The outer border of quadratus lumborum lies external to that of the erector spinae at the iliac crest and internal to it at the twelfth rib.

As a rule the tip of the twelfth rib lies 2 inches vertically above the centre of the iliac crest.

The "triangle of Petit" is a narrow triangular space formed by the outer border of latissimus dorsi, the posterior border of obliquus externus, and the iliac crest.