AnatoMemory

Muscle

Transversus abdominis

Deepest flat abdominal muscle

TrunkMuscular system

High-yield

Transverse fibres act as a "corset"; core-stability muscle. Contributes to the conjoint tendon.

Overview

The deepest flat abdominal muscle with transverse fibres that compress and support the abdominal viscera like a corset.

Reference facts

Origin
Thoracolumbar fascia, iliac crest, lateral inguinal ligament, and costal cartilages 7-12
Insertion
Linea alba, pubic crest, and pectineal line (conjoint tendon)
Action
Compresses and supports the abdominal viscera; increases intra-abdominal pressure
Innervation
Thoracoabdominal nerves (T7-T12), subcostal, and L1
Blood supply
Lower posterior intercostal / deep circumflex iliac arteries

Frequently asked questions

What does the transversus abdominis do?

The transversus abdominis compresses and supports the abdominal viscera; increases intra-abdominal pressure.

What nerve innervates the transversus abdominis?

The transversus abdominis is innervated by the thoracoabdominal nerves (T7-T12), subcostal, and L1.

Where does the transversus abdominis attach?

The transversus abdominis originates from the thoracolumbar fascia, iliac crest, lateral inguinal ligament, and costal cartilages 7-12 and inserts on the linea alba, pubic crest, and pectineal line (conjoint tendon).

What is the blood supply of the transversus abdominis?

The transversus abdominis is supplied by the lower posterior intercostal / deep circumflex iliac arteries.