Cadaveric Anatomy: Abdominal Wall, Posterior Abdomen, and Deep Back Muscles

Comprehensive vocabulary flashcards identifying and defining muscular and fascial structures of the anterolateral abdominal wall, posterior abdominal wall, and back based on cadaveric dissections.

Transversus abdominis muscle

The innermost flat muscle of the anterolateral abdominal wall, situated deep to the internal oblique; characterized by horizontally oriented fibers that compress abdominal contents and stabilize the trunk.

Inguinal ligament

A dense fibrous band formed by the rolled-under inferior border of the external oblique aponeurosis, spanning from the anterior superior iliac spine (ASIS) to the pubic tubercle and forming the inferior boundary of the inguinal canal.

Psoas major muscle

A thick, fusiform muscle of the posterior abdominal wall originating from the transverse processes, bodies, and intervertebral discs of T12–L5 vertebrae; it passes deep to the inguinal ligament to insert onto the lesser trochanter of the femur, acting as a primary hip flexor.

Quadratus lumborum muscle

A quadrilateral muscle sheet of the posterior abdominal wall located lateral to the psoas major, extending from the iliac crest and iliolumbar ligament to the 12th rib and L1–L4 transverse processes; functions to laterally flex the vertebral column and fix the 12th rib during inspiration.

Spinalis muscle

The most medial column of the erector spinae muscle group, positioned immediately adjacent to the spinous processes in the thoracic and cervical regions; acts to extend the vertebral column.

Longissimus muscle

The intermediate and largest column of the erector spinae muscle group, running vertically between the medial spinalis and the lateral iliocostalis; functions to extend and laterally flex the vertebral column.

Serratus posterior superior muscle

A thin, quadrilateral intermediate back muscle situated deep to the rhomboids, originating from the lower ligamentum nuchae and spinous processes of C7–T3 and inserting onto ribs 2–5; functions to elevate the upper ribs during inspiration.

Thoracolumbar fascia

An extensive, multi-layered aponeurotic sheath in the lumbar and thoracic regions of the back that encloses the deep back muscles and provides origin attachment for the latissimus dorsi, internal oblique, and transversus abdominis muscles.

Rhomboid major muscle

A broad, diamond-shaped extrinsic back muscle lying deep to the trapezius, originating from the spinous processes of vertebrae T2–T5 and inserting onto the medial border of the scapula inferior to the scapular spine; retracts, elevates, and rotates the scapula.

Rhomboid minor muscle

A narrow, cylindrical extrinsic back muscle positioned immediately superior to the rhomboid major, originating from the inferior nuchal ligament and spinous processes of C7–T1 and inserting onto the medial border of the scapula at the root of the scapular spine; retracts and stabilizes the scapula.