Why is there an arcuate line

Check for errors and try again. Thank you for updating your details. Log In. Sign Up. Become a Gold Supporter and see no ads. Log in Sign up. Articles Cases Courses Quiz. About Recent Edits Go ad-free. Edit article. View revision history Report problem with Article. It is also where the inferior epigastric vessels perforates the rectus abdominus. Superior to the arcuate line, the internal oblique aponeurosis splits to envelope the rectus abdominis muscle.

Inferior to the arcuate line, the internal oblique and transversus abdominis aponeuroses merge and pass superficial to the rectus muscle. Above the arcuate line, the rectus abdominis is surrounded by an anterior layer of the rectus sheath and a posterior layer.

The anterior layer is derived from the external oblique aponeurosis and the anterior laminina of the internal oblique aponeurosis. The posterior layer is made up of the posterior lamina of the internal oblique aponeurosis and the tranverse abdominal aponeurosis.

After the arcuate line, all three muscle aponeuroses make up the rectus sheath, that is now only anterior to the rectus abdominis and not posterior to it at all.

Therefore, inferior to the arcuate line, the rectus abdominis rests directly on the transversalis fascia. If one dissects the anterolateral abdominal wall , the arcuate line may be difficult to see, since all the aponeuroses are translucent. Category : Abdomen. Read what you need to know about our industry portal bionity. Microsoft is encouraging users to upgrade to its more modern Edge browser for improved security and functionality.

This site is intended for healthcare professionals. Sign in. Sign in Register. The posterior leaflet of the sheath is formed, superficial to deep, from the: posterior part of the internal oblique aponeurosis transversus abdominis aponeurosis transversalis fascia Below the arcuate line, there is a transition so that all but the transversalis fascia pass anterior to rectus abdominis.