Rectus Abdominis

Description

Running vertically on either side of the linea alba, the paired rectus abdominis muscles occupy the anterior abdominal wall from the pubic crest and pubic symphysis inferiorly to the xiphoid process and the fifth through seventh costal cartilages superiorly. Several tendinous intersections segment each muscle belly transversely, creating the familiar rectus “blocks” while tethering the muscle to the overlying rectus sheath. Laterally, the rectus margins approach the semilunar lines where the aponeuroses of external oblique, internal oblique, and transversus abdominis contribute to the sheath. Midline anatomy matters here. For teaching and clinical work, this anterior torso view clarifies where rectus abdominis sits relative to the costal margin and pelvis, a relationship that guides palpation, trocar placement, and interpretation of abdominal wall contour. Separation or widening at the linea alba (diastasis recti) is assessed by the midline interval between the medial rectus borders, while true ventral hernias protrude through a fascial defect in or near the rectus sheath. The tendinous intersections also explain why rectus hematoma, often from epigastric vessel injury or anticoagulation, can be confined to a segment and mimic an intraabdominal acute abdomen. Ideal for gross anatomy and kinesiology coursework when discussing trunk flexion, posterior pelvic tilt, and force transfer across the linea alba, this illustration also supports surgical education on midline laparotomy, paramedian incisions, and layered closure of the rectus sheath. It fits well in patient-facing materials on abdominal wall conditions and postoperative rehabilitation where accurate surface mapping reduces confusion. Anatomical accuracy verified by SciePro's Medical Advisory Board.