The aponeurosis of the

abdominal external oblique muscle The abdominal external oblique muscle (also external oblique muscle, or exterior oblique) is the largest and outermost of the three flat abdominal muscles of the lateral anterior abdomen. Structure The external oblique is situated on the lateral ...

is a thin but strong membranous structure, the fibers of which are directed downward and medially. It is joined with that of the opposite muscle along the middle line, and covers the whole of the front of the abdomen; above, it is covered by and gives origin to the lower fibers of the

pectoralis major The pectoralis major () is a thick, fan-shaped or triangular convergent muscle, situated at the chest of the human body. It makes up the bulk of the chest muscles and lies under the breast. Beneath the pectoralis major is the pectoralis minor, a ...

; below, its fibers are closely aggregated together, and extend obliquely across from the

anterior superior iliac spine The anterior superior iliac spine (abbreviated: ASIS) is a bony projection of the iliac bone, and an important landmark of surface anatomy. It refers to the anterior extremity of the iliac crest of the pelvis. It provides attachment for the ingui ...

to the

pubic tubercle The pubic tubercle is a prominent tubercle on the superior ramus of the pubis bone of the pelvis. Structure The pubic tubercle is a prominent forward-projecting tubercle on the upper border of the medial portion of the superior ramus of th ...

and the pectineal line to form the inguinal ligament. In the middle line, it interlaces with the

aponeurosis An aponeurosis (; plural: ''aponeuroses'') is a type or a variant of the deep fascia, in the form of a sheet of pearly-white fibrous tissue that attaches sheet-like muscles needing a wide area of attachment. Their primary function is to join musc ...

of the opposite muscle, forming the linea alba, which extends from the

xiphoid process The xiphoid process , or xiphisternum or metasternum, is a small cartilaginous process (extension) of the inferior (lower) part of the sternum, which is usually ossified in the adult human. It may also be referred to as the ensiform process. Both ...

to the

pubic symphysis The pubic symphysis is a secondary cartilaginous joint between the left and right superior rami of the pubis of the hip bones. It is in front of and below the urinary bladder. In males, the suspensory ligament of the penis attaches to the pubic ...

. That portion of the aponeurosis which extends between the anterior superior iliac spine and the pubic tubercle is a thick band, folded inward, and continuous below with the fascia lata; it is called the

inguinal ligament The inguinal ligament (), also known as Poupart's ligament or groin ligament, is a band running from the pubic tubercle to the anterior superior iliac spine. It forms the base of the inguinal canal through which an indirect inguinal hernia may dev ...

. The portion which is reflected from the inguinal ligament at the pubic tubercle is attached to the pectineal line and is called the

lacunar ligament The lacunar ligament, also named Gimbernat’s ligament, is a ligament in the inguinal region. It connects the inguinal ligament to the pectineal ligament, near the point where they both insert on the pubic tubercle. Structure The lacunar ligam ...

. From the point of attachment of the latter to the pectineal line, a few fibers pass upward and medialward, behind the medial crus of the superficial inguinal ring, to the linea alba; they diverge as they ascend, and form a thin triangular fibrous band which is called the

reflected inguinal ligament The reflected inguinal ligament (triangular fascia) is a layer of tendinous fibers of a triangular shape, formed by an expansion from the lacunar ligament and the inferior crus of the subcutaneous inguinal ring. It passes medialward behind the spe ...

. In the aponeurosis of the external oblique, immediately above the

pubic crest Medial to the pubic tubercle is the pubic crest, which extends from this process to the medial end of the pubic bone. It gives attachment to the conjoint tendon, the rectus abdominis, the abdominal external oblique muscle, and the pyramidalis m ...

, is a triangular opening, the superficial inguinal ring, formed by a separation of the fibers of the aponeurosis in this situation.

References

External links

* * * - "Anterior Abdominal Wall: The External Abdominal Oblique Muscle" * Abdomen Muscles of the torso {{Portal bar, Anatomy