Diagram of the course and branches of a typical intercostal nerve.
Intercostal nerves, the superficial muscles having been removed.
|Innervates||Rectus abdominis muscle|
The anterior divisions of the seventh, eighth, ninth, tenth, and eleventh thoracic intercostal nerves are continued anteriorly from the intercostal spaces into the abdominal wall; hence they are named thoraco-abdominal nerves (or thoracicoabdominal intercostal nerves).
The intercostal nerves are part of the somatic nervous system, and arise from the anterior rami of the thoracic spinal nerves from T1 to T11. The intercostal nerves are distributed chiefly to the thoracic pleura and abdominal peritoneum and differ from the anterior rami of the other spinal nerves in that each pursues an independent course without plexus formation.
They have the same arrangement as the upper ones as far as the anterior ends of the intercostal spaces, where they pass behind the costal cartilages, and between the Obliquus internus and Transversus abdominis, to the sheath of the Rectus abdominis, which they perforate.
They supply the Rectus abdominis and end as the anterior cutaneous branches of the abdomen; they supply the skin of the front of the abdomen.
The abdomen constitutes the part of the body between the thorax (chest) and pelvis, in humans and in other vertebrates. The abdomen is the frontal part of the abdominal segment of the trunk, the dorsal part of this segment being the back of the abdomen. The region occupied by the abdomen is termed the abdominal cavity. In arthropods it is the posterior tagma of the body; it follows the thorax or cephalothorax. The abdomen stretches from the thorax at the thoracic diaphragm to the pelvis at the pelvic brim. The pelvic brim stretches from the lumbosacral joint to the pubic symphysis and is the edge of the pelvic inlet. The space above this inlet and under the thoracic diaphragm is termed the abdominal cavity. The boundary of the abdominal cavity is the abdominal wall in the front and the peritoneal surface at the rear.
The lower intercostal nerves supply the Intercostales and abdominal muscles; the last three send branches to the Serratus posterior inferior. About the middle of their course they give off lateral cutaneous branches.
These pierce the Intercostales externi and the Obliquus externus abdominis, in the same line as the lateral cutaneous branches of the upper thoracic nerves, and divide into anterior and posterior branches, which are distributed to the skin of the abdomen and back; the anterior branches supply the digitations of the Obliquus externus abdominis, and extend downward and forward nearly as far as the margin of the Rectus abdominis; the posterior branches pass backward to supply the skin over the Latissimus dorsi.
The rectus abdominis muscle, also known as the "abdominal muscle" or "abs", is a paired muscle running vertically on each side of the anterior wall of the human abdomen, as well as that of some other mammals. There are two parallel muscles, separated by a midline band of connective tissue called the linea alba. It extends from the pubic symphysis, pubic crest and pubic tubercle inferiorly, to the xiphoid process and costal cartilages of ribs V to VII superiorly. The proximal attachments are the pubic crest and the pubic symphysis. It attaches distally at the costal cartilages of ribs 5-7 and the xiphoid process of the sternum.
The transverse abdominal muscle (TVA), also known as the transverse abdominis, transversalis muscle and transversus abdominis muscle, is a muscle layer of the anterior and lateral abdominal wall which is deep to the internal oblique muscle. It is thought by most fitness instructors to be a significant component of the core.
The internal oblique muscle is a muscle in the abdominal wall that lies below the external oblique and just above the transverse abdominal muscles.
The external oblique muscle is the largest and the outermost of the three flat muscles of the lateral anterior abdomen.
In human anatomy, inferior epigastric artery refers to the artery that arises from the external iliac artery and anastomoses with the superior epigastric artery. Along its course, it is accompanied by a similarly named vein, the inferior epigastric vein. These epigastric vessels form the lateral border of Hesselbach's triangle, which outlines the area through which direct inguinal hernias protrude.
In anatomy, the abdominal wall represents the boundaries of the abdominal cavity. The abdominal wall is split into the posterior (back), lateral (sides) and anterior (front) walls.
The femoral nerve is a nerve in the thigh that supplies skin on the upper thigh and inner leg, and the muscles that extend the knee.
The iliohypogastric nerve is a nerve that originates from the lumbar plexus that supplies sensation to skin over the lateral gluteal region and motor to the internal and transverse abdominal muscles.
The ilioinguinal nerve is a branch of the first lumbar nerve (L1). It separates from the first lumbar nerve along with the larger iliohypogastric nerve. It emerges from the lateral border of the psoas major just inferior to the iliohypogastric, and passes obliquely across the quadratus lumborum and iliacus. The ilioinguinal nerve then perforates the transversus abdominis near the anterior part of the iliac crest, and communicates with the iliohypogastric nerve between the transversus and the internal oblique muscle.
The obturator nerve in human anatomy arises from the ventral divisions of the second, third, and fourth lumbar nerves in the lumbar plexus; the branch from the third is the largest, while that from the second is often very small.
The falciform ligament is a ligament that attaches the liver to the anterior (ventral) body wall, and separates the liver into the left medial lobe and left lateral lobe. The falciform ligament, from Latin, meaning 'sickle-shaped', is a broad and thin fold of peritoneum, its base being directed downward and backward and its apex upward and backward. The falciform ligament droops down from the hilum of the liver.
The lumbar arteries are arteries located in the lower back or lumbar region. The lumbar arteries are in parallel with the intercostals.
The intercostobrachial nerves are cutaneous branches of the intercostal nerves.
The crest of the ilium is the superior border of the wing of ilium and the superiolateral margin of the greater pelvis.
The anterior division of the twelfth thoracic nerve is larger than the others; it runs along the lower border of the twelfth rib, often gives a communicating branch to the first lumbar nerve, and passes under the lateral lumbocostal arch.
The arcuate line of the abdomen, linea semicircularis or Douglas' line is a horizontal line that demarcates the lower limit of the posterior layer of the rectus sheath. It is also where the inferior epigastric vessels perforate the rectus abdominis.
The intercostal arteries are a group of arteries that supply the area between the ribs ("costae"), called the intercostal space. The highest intercostal artery is an artery in the human body that usually gives rise to the first and second posterior intercostal arteries, which supply blood to their corresponding intercostal space. It usually arises from the costocervical trunk, which is a branch of the subclavian artery. Some anatomists may contend that there is no supreme intercostal artery, only a supreme intercostal vein.
Lateral cutaneous branch can refer to:
The rectus sheath, also called the rectus fascia, is formed by the aponeuroses of the transverse abdominal and the external and internal oblique muscles. It contains the rectus abdominis and pyramidalis muscles.