Internal Thoracic Artery

The internal thoracic artery (also known as the mammary artery) arises from the first part of the subclavian artery in the neck. It supplies the anterior wall of the body extending from the clavicle to the region of the umbilicus.

Grey’s Anatomy 20th edition

The internal thoracic artery lies behind the costal cartilages, descending vertically on the pleura, lying about a finger breadth lateral to the sternum.

Internal thoracic artery ends in the sixth intercostal space. It divides into two terminal branches:

1. Superior epigastric artery

2. Musculophrenic artery

Grey’s Anatomy 20th edition

Branches:

1. Anterior intercostal arteries:

There are two anterior intercostal arteries which supply the upper six intercostal spaces.

2. Perforating arteries:

The perforating arteries travel along with the  terminal branches of the corresponding intercostal nerves.

3. Pericardiacophrenic artery:

Pericardiacophrenic artery supplies the pericardium and travels with the phrenic nerve.

4. Mediastinal Arteries:

The mediastinal arteries supply the structures within the anterior mediastinum.

Terminal Branches:

1. Superior epigastric artery:

The superior epigastric artery enters the rectus sheath located in the anterior abdominal wall, lying behind the rectus abdominus and supplies the rectus muscle till the region of the umbilicus.

2. Musculophrenic artery:

Musculophrenic artery supplies the diaphragm and the lower intercostal spaces, and travels around the costal margin of the diaphragm.