Muscles of Abdominal Wall Flashcards Preview

Anatomy - Thorax and Abdomen > Muscles of Abdominal Wall > Flashcards

Flashcards in Muscles of Abdominal Wall Deck (12)
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Linea alba

Extends from the xiphoid process to the pubic symphysis



Small triangular muscle that lies in the rectus sheath anterior to the inferior part of the rectus abdominis - absent in 20% of people


Rectus sheath

Encloses the rectus abdominis muscles and is formed by the interlaced aponeuroses of the flat abdominal muscles


What are the three flat abdominal muscles?

External oblique, internal oblique, and transverse abdominis


What are the two vertical muscles?

Rectus abdominis and the pyramidalis


Arcuate line

Demarcates the transition between the posterior rectus sheath covering the superior three quarters of the rectus abdominis proximally and the tranversalis fascia covering the inferior quarter - and sits posterior to rectus abdominis


Cremaster muscle

Formed by the lowest fascicles of the internal oblique muscle arising from the inguinal ligament - draws the testis superiorly in the scrotum when it is cold and relaxes to descend the testis deeply in the scrotum when it is warm - innervated by the genital branch of the genitofemoral nerve (L1,L2)


Rectus sheath superior to umbilicus (arcuate line)

-External oblique - front and back fascia go anterior to the rectus abdominis
-Internal oblique - front fascia goes to the anterior side and back fascia goes to the posterior side of the rectus abdominis
-Transverses abdominis - front and back fascia go posterior to the rectus abdominis


Rectus sheath inferior to umbilicus (arcuate line)

All abdominal muscle fascias run anterior to rectus abdominis and transversalis fascia stays posterior


Transversalis fascia

Lines the transverse abdominis


What are the nerves of the anterior abdominal wall?

Thoracoabdominal nerve (anterior rami of T7-T11) which branch into the anterior and lateral cutaneous branches, subcostal nerve (anterior rami of T12), and iliohypogastric and ilioguinal nerves (anterior rami of L1) and spinal nerve T11


Dartos muscle

Assists in testicular elevation as it produces contraction of the skin of the scrotum