Anatomy clinical correlates: Peritoneum and diaphragm

00:00 / 00:00


Anatomy clinical correlates: Peritoneum and diaphragm

USMLE® Step 1 questions

0 / 10 complete

USMLE® Step 2 questions

0 / 11 complete


USMLE® Step 1 style questions USMLE

of complete

USMLE® Step 2 style questions USMLE

of complete

A 26-year-old man is fighting in an international mixed martial arts contest. During the tournament, he sustains repeated abdominal blows from the opponent, followed by repeated blows to the left temple that render him unconscious. An on-site sports physician immediately assesses the patient. Temperature is 37.0°C (98.6°F), pulse is 136/min, respirations are 25/min, and blood pressure is 130/66 mmHg. The patient’s oxygen saturation is 92%. As the patient awakens, he reflexively guards his left lower chest. An urgent chest radiograph is done on-site and is shown below. Which of the following explains why the diaphragmatic hernia seen below occurred on the left side, as opposed to the right?  

Image reproduced from Radiopedia

Memory Anchors and Partner Content


The peritoneum is a transparent serous membrane that lines the abdominal cavity and covers the abdominal organs, whereas the diaphragm is a skeletal muscle that separates the thoracic cavity from the abdominal cavity and plays an important role in respiration.

Understanding the anatomy of these structures allows us to better understand the unique clinical conditions that affect them.

Let’s start off by reviewing the innervation of visceral and somatic pain in the abdomen. The peritoneum is made up of two continuous layers, the visceral peritoneum and parietal peritoneum.

The inner visceral layer mainly covers the abdominal organs and has a visceral nerve supply, where the outer parietal layer mainly covers the internal surface of the abdominopelvic walls and has a somatic nerve supply.

Furthermore, both the visceral and somatic nerve supply of the peritoneum sense pain during different clinical conditions; however, the way in which they sense pain is different.

The visceral peritoneum is innervated by the autonomic nervous system. When the visceral peritoneum is irritated, pain sensation is detected by visceral afferent fibers which travel with the autonomic nerves, mainly sympathetic nerve fibers, back to the spinal cord.

Visceral pain is typically sensed as a diffuse, dull pain which is not very well localized, and the pain is often referred to the midline region of the dermatomal areas of the same spinal level as the autonomic nerve supply.

Typically, pain sensed by the foregut visceral peritoneum is referred to the epigastric region, midgut visceral pain is referred to the umbilical region, and hindgut visceral pain is referred to the hypogastric region.


  1. "Grant's Dissector" Lippincott Williams & Wilkins (2012)
  2. "Gray's Anatomy for Students E-Book" Elsevier Health Sciences (2009)
  3. "Gray's Anatomy for Students E-Book" Elsevier Health Sciences (2009)
  4. "Harrison's Principles of Internal Medicine, 18th Edition" McGraw Hill Professional (2011)
  5. "Evidence-Based Physical Diagnosis E-Book" Elsevier Health Sciences (2016)
  6. "Uncommon causes of peritonitis in patients undergoing peritoneal dialysis" Archives of Internal Medicine (1981)
  7. "Peritoneal repair and post-surgical adhesion formation" Human Reproduction Update (2001)
  8. "Primordial GATA6 macrophages function as extravascular platelets in sterile injury" Science (2021)
  9. "Peritoneal Cavity" Imaging Anatomy: Chest, Abdomen, Pelvis (2017)
  10. "Surgical Procedures for Advanced Local and Regional Malignancies of the Breast" The Breast (2018)
  11. "Optimal choice of dialysis access for chronic kidney disease patients: developing a life plan for dialysis access" Semin Nephrol (2012)

Copyright © 2023 Elsevier, its licensors, and contributors. All rights are reserved, including those for text and data mining, AI training, and similar technologies.

Cookies are used by this site.

USMLE® is a joint program of the Federation of State Medical Boards (FSMB) and the National Board of Medical Examiners (NBME). COMLEX-USA® is a registered trademark of The National Board of Osteopathic Medical Examiners, Inc. NCLEX-RN® is a registered trademark of the National Council of State Boards of Nursing, Inc. Test names and other trademarks are the property of the respective trademark holders. None of the trademark holders are endorsed by nor affiliated with Osmosis or this website.