How do you remember the anatomical structures housed by the retroperitoneum?

Nick Love, PhD, a second-year medical student at Stanford University, created these whimsical images to help remember parts of the human anatomy.

All images courtesy of Nick Love, PhD

The heart's left ventricle pumps blood throughout the entire body. After leaving the left ventricle, blood enters the aorta, brachiocephalic trunk, the left common carotid artery, and the left subclavian artery; these structures comprise the aortic arch.

After supplying the left subclavian artery, the aorta descends into the lower body. There are six major arteries branching from the descending aorta: the celiac trunk, superior mesenteric, renal, gonadal, inferior mesenteric, and common iliac arteries.

Lymphatic vessels can be difficult to distinguish from other tube-like structures. In the thorax, the thoracic duct is normally between the azygous vein and the esophagus.

When entering the abdomen from the thorax, a structure must "pierce" the diaphragm. The inferior vena cava (IVC) pierces the diaphragm at thoracic vertebra T8. The vagus nerve and esophagus pierce at T10. The aorta, thoracic duct, and azygous vein pierce at T12.

The anatomic space behind the peritoneum is known as the retroperitoneum. It houses the suprarenal (adrenal) glands, aorta (IVC), duodenum (second and third segments), pancreas (except the tail), ureters, colon (the ascending and descending parts), kidneys, esophagus, and rectum.

Within the lower abdominal cavity are the ureters and gonadal arteries, which are in close proximity and descend toward the pelvis. During cadaver dissection and examinations, please find the urine (water) carrying ureters posterior to the anterior gonadal arteries (uterine artery "bridge").

*Vas deferens and uterine artery

A commonly used route for catheterization is the femoral vein, found within the femoral triangle. The contents of the femoral triangle, from lateral to medial, are the femoral nerve, femoral artery, femoral vein, an "empty space," and lymphatic vessel.

The body is asymmetric in regard to its orientation of pulmonary arteries to their nearby bronchi. Namely, the right pulmonary artery is anterior to a bronchus whereas the left pulmonary artery is superior to a bronchus.

The external carotid arteries provide oxygenated blood to structures of the throat, face, and scalp. The external carotid artery branches at the mid-neck level, forming the superior thyroid, ascending pharyngeal, lingual, facial, occipital, posterior auricular, superficial temporal, and maxillary arteries.

The facial nerve (cranial nerve VII) innervates the muscles that control facial expressions, including those governing blinking and smiling. After leaving the skull, the facial nerve splits into the temporal, zygomatic, buccal, mandibular, cervical, and posterior auricular branches.

The brachial plexus is derived from nerves that exit the spinal cord at C5, C6, C7, C8, and T1. These nerves merge, crisscross, and split in characteristic fashion to innervate the upper limb. From proximal to distal, the brachial plexus is organized via roots, trunks, divisions, cords, and branches.

The roots of the brachial plexus differentially contribute to the musculocutaneous (C5, C6, C7), axillary (C5, C6), radial (C5, C6, C7, C8, T1), median (C5, C6, C7, C8, T1), and ulnar (C8, T1) nerves. Variations to these rules, however, are known.

The brachial plexus helps form the radial nerve. The radial nerve innervates the brachioradialis, the extensor muscles of the forearm, the anconeus muscle, and the supinator and triceps muscles.

Raising one's arms towards the heavens involves the serratus anterior muscle, innervated by the long thoracic nerve (cervical spinal nerves 5, 6, and 7). Injury to the long thoracic nerve results in what is described as a "winged scapula."

The shoulder joint rotates, facilitating a variety of movement. The muscles of the shoulder "rotator cuff" joint are the supraspinatus, infraspinatus, teres minor, and subscapularis muscles.

Muscles from the chest (pectoralis major), back (latissimus dorsi), and scapula (teres major) attach to the bicipital groove of the humerus and help move the arm. At the bicipital groove, latissimus dorsi attaches to the humerus between pectoralis major (lateral) and teres major (medial).