ORIGIN: Spinal cord segment T10.
COURSE/DISTRIBUTION: This nerve takes origin from spinal cord segment T10 and leaves the vertebral canal by passing through the intervertebral foramen between T10 and T11 vertebrae. It immediately divides into two rami- dorsal and ventral rami.
It immediately turns backwards, close to T10 costotransverse joint and divides into medial and lateral branches.
|The medial branch immediately passes between the joint and the superior costotransverse ligament with the corresponding intertransversarii. It runs between the semispinalis thoracis and multifidus. Its cutaneous branches now enter the skin at the side of T10 vertebra to supply the medial part of posterior aspect of T10 dermatome.|
|The lateral branch runs laterally and occupies the interval between the superior costotransverse ligament and the intertranversarii. It then turns on the medial aspect of the T10 levator costae. It runs between the longissimus thoracis and iliocostalis thoracis. Its muscular branches supply these muscles before it then pierces the skin of the remaining lateral part of the T10 dermatome to supply it with cutaneous branches.|
|Continues as the tenth intercostal nerve, which runs in the costal groove of the 10th rib under the 10th posterior intercostal artery. The 10th superior anterior intercostal artery later replaces this artery in the same groove. It later passes through the digitations of the diaphragm and the transversus abdominis. It lies in the interval between the internal oblique muscle of abdomen and the transversus abdominis. It enters the rectus sheath and passes to the rectus abdominis by piercing its lateral wall. It supplies all these muscles of the anterior abdominal wall.|
ROOT VALUE: T10
Electronic School of Medicine
Creator: Oluwole Ogunranti