(1) The middle of abdomen, from xiphoid process down to pubic symphysis, represents the white line of abdominal wall all the time. There is an umbilical cord at the midpoint of the white line. You can see that a muscular person has eight rectus abdominis stretching to both sides. You can see from the outside that these muscles are crossed by three or more tendons. One is near the xiphoid cartilage, one is in the navel, and the other is in between.

(2) The white line and these three conditional tendons divide the abdomen into "six grids". This is exactly what bodybuilders are after. The upper edge of abdomen is the lower edge of rib connected by (8,9, 10) pseudoosteochondral. The lower margin is anterior iliac spine and Poupart ligament, which starts from anterior superior iliac spine and ends at pubic spine. The lower bound is slotted on the body surface.

(3) On both sides above the pubic spine are groin rings, which are the openings of the abdominal muscle layer, and the male spermatic cord passes through them. Inguinal hernia can occur here. One way to quickly know the position of the abdomen and its contents is to make three horizontal lines and two vertical lines. It is located at the midpoint of the connecting line between the suprasternal notch and the upper part of pubic symphysis, and intersects the gastric pylorus one inch to the right of the midline.

(4) The renal hilum is slightly lower than it, and its left end is close to the lower bound of the spleen. At the back, it meets the first lumbar vertebra. The second line is the subcostal line, which passes through the lowest point of the rib arch (the tenth rib). It meets the upper part of the third lumbar vertebra, about an inch above the navel. It roughly represents the position of transverse colon, the lower end of kidney and the upper boundary of transverse part of duodenum (the third part).