The iliac region is one of the parts of the posterior wall of the abdomen and has the shape of a hollow. Its upper border is the ilium (PC), in particular its crest, the front border is the beginning of the bone and ligament, the inside is the connection with the sacrum, the lower border is the nameless line. In this case, the PC acts as the skeleton of this area, to which the muscles of the back wall of the abdomen are attached. Together, the muscles and bones form a dense case.
Thus, large iliac bones, which have rounded tops, are attached to the sacrum on both sides, therefore they are well felt on the human body.
The ilium is the largest of all the bones that form the pelvic skeleton of a person. Its lower part is somewhat thickened and is called the body of the PC, which forms the upper part of the acetabulum. The sacrum and femur connect to the ilium. During puberty, the PC fuses with the pubic and sciatic bones in the acetabulum, thus forming a pelvic bone.
On the inner side of the body there is a line in the shape of an arc, and above is a wide part of the bone, called the wing of the PK, the lower part of which is narrowed, and the upper - expanded. The edge of the wing is thickened, abdominal muscles are attached to it, traces of which are imprinted on the bone in the form of three lines (lips): external, internal and intermediate. It should be noted that the upper parts of the wings are called iliac crests. The crest has an S-shape and ends in front of the anterior upper PC, which can be felt on the human body through the skin, and behind the posterior upper iliac bone.
Note that the front edge of the ilium is fused with the pubic bone, and the posterior edge borders the sciatic notch. The outer part of the wing is the place of attachment of the gluteal muscles, and on the inner part of the wing, referred to as the iliac fossa, is the articular ear-shaped surface, which is the junction with the surface of the sacrum. Above it is the iliac tuberosity, which serves to attach the ligaments.
The iliac fossa is the site of attachment of the iliac muscle. It is adjacent to the muscle lumbar and originates from the upper part of the fossa, the inner lip of the crest and the anterior sacral and lumbar ligaments. With the psoas major muscle, the ileum participates in the formation of muscle mass of the wall of the abdominal cavity (back). Its functions include hip flexion.
So, the upper part of the PC is rounded, the front and back form two protrusions, and the outer part is somewhat elevated. In general, the relief of the bone depends on the muscles in the attachment points of which various lines, crests, pits and awns have formed.
Thus, The ilium is one of three components that form a single pelvic bone. In humans, it connects to the sacral bone (fusion of five vertebrae) and fuses with the other two components of the pelvis in the area of the acetabulum . In this area, muscles are attached, in particular, the iliopsoas, which, due to its contractions, makes the limb move forward, that is, controls their movement, and also stabilizes the pelvis, bends the thigh and lumbar spine.
Summing up, it should be noted once again that the ilium whose function is to strengthen the muscles, participates in the process of formation and control of the movements of the lower extremities. Combined with joints and moved by muscles, the PC also forms a defense for the soft parts of the body, while ensuring smooth movements. In addition, as part of the human skeleton, the ilium serves as a skeleton to which other parts of the body are attached , namely the lower limbs.