Outer oblique abdominal muscle

Outer oblique abdominal muscle , t. Ob liquus Externus Abdominis , Flat, wide, starts 8 teeth from the lateral surface of the eight lower ribs. On the anterolateral surface of the thorax, the five upper teeth are wedged between the lower teeth of the anterior dentate muscle, and the three lower ones between the teeth of the latissimus dorsi. The bunches of the external oblique muscle are directed obliquely downward and anterior to the aponeurosis. The upper part of the aponeurosis is directed to the median line and participates in the formation of the anterior wall of the vagina of the rectus abdominis muscle.

The bundles of the aponeurosis of this muscle, like all the wide abdominal muscles, reaching the median line, are intertwined with bundles of aponeuroses of the same-named muscles of the opposite side, and thus a white belly line is formed , linea Alba .

The lower fascicles of the external oblique muscle are attached to the anterior section of the outer lip of the iliac crest. Middle beams of the aponeurosis are thrown over the anterior incision of the hip bone and stretched between the superior anterior iliac spine and the pubic bone. At the same time, the lower edge of the aponeurosis, turning back and down, forms a trough. This thickened lower edge of the aponeurosis, stretched between the superior anterior iliac spine on one side and the pubic tubercle and pubic symphysis, on the other, is called the inguinal ligament, lig . Inguinale , or inguinal arc, arcus Inguinalis . In the pubic bone, the bundles of the inguinal ligament diverge and form two legs. One of them is the medial leg, crus Mediale , is attached to the symphysis, part of its beams passes to the opposite side. Other - lateral pedicle, crus Laterale , is attached to the pubic hillock of the same side. Between the legs remains a triangular slit, the upper corner of which is rounded: here are located the arc- shaped mezhozhkovye fibers, fibrae Intercrurales . From the inner part of the lateral stem, the bundles are directed towards the inside and medially to the anterior plate of the vagina of the rectus abdominis, - the bent ligament, lig .
Reflexum .

The oval aperture in the aponeurosis of the external oblique abdominal muscle, bounded by two legs of the inguinal ligament, intergranular fibers and the bent ligament, is the superficial inguinal ring, anulus Inguinalis Superficialis . Through him, the men come out with a spermatic cord, funiculus Spermaticus , And in women - a round ligament of the uterus, lig . Teres Uteri (Figure 321) (through it, internal organs may protrude, forming a so-called inguinal hernia). From the medial end of the lateral stem, one muscle bundle goes posteriorly and laterally along the edge of the upper branch of the pubic bone - this lacunar ligament, lig . Lacunare . It "rounds" the acute angle between the inguinal ligament and the pubic bone.

Behind the posterior edge of the external oblique abdominal muscle, above the iliac crest, in the trunk wall is a triangular section - the lumbar triangle, trigonum Lumbale .

Function: is the abdominal muscle; Cutting on one side, rotates the trunk in the opposite direction; Bilateral reduction with a strengthened pelvis pulls the chest and flexes the spine.

Innervation: nn. Intercostales (Th _v - Th _xII , L1), n. Iliohypogaslricus (Th12 -L1 ), N. Ilioinguinalis (L1).

Blood supply: aa. Intercostales posteriores, Thoracica lateralis, circumflexa ilium superficialis.