Endoabdominal and transversalis fascia
The layered structure of the anterior abdominal wall from the inside concludes with the endoabdominal fascia (fascia endoabdominalis). It covers the inner surface of the abdominal muscles. Its anterolateral section, the transversalis fascia (fascia transversalis), is of the greatest practical significance. This name is due to the fact that this layer lies directly adjacent to the transversus abdominis muscle of the same name.
The thickness of the transversalis fascia is uneven and depends on the topographic zone:
- In the upper abdomen, it is a very thin, delicate plate.
- In the inferior direction, approaching the inguinal ligament, the fascia thickens significantly, turning into a strong and dense fibrous plate. This thickening plays an important role in strengthening the lower parts of the abdominal wall.
Deep inguinal ring and spermatic fascia
Special attention when studying the transversalis fascia is paid to the region of the inguinal canal. It is here that the deep inguinal ring (internal opening of the inguinal canal) is formed.
In this zone, the transversalis fascia does not simply end, but forms a characteristic funnel-shaped depression that extends directly into the lumen of the inguinal canal. Pushing into the canal, the fascia continues onto the structures emerging from it. This forms the internal spermatic fascia (fascia spermatica interna). It is a direct continuation of the transversalis fascia and covers the elements of the spermatic cord, descending down to the testis.
Preperitoneal tissue
The next layer, located deeper (closer to the organs) than the endoabdominal fascia, is the preperitoneal tissue. Its main topographic function is to separate the transversalis fascia from the parietal peritoneum.
The distribution of adipose tissue in the preperitoneal space is also extremely uneven:
- Poorly developed: in the upper abdomen and on the anterior surface.
- Well developed: in the posterior regions, as well as in the lower part of the anterior abdominal wall, especially as it approaches the pubic symphysis. Here, accumulations of tissue allow the peritoneum to be more mobile relative to the fascial layer.
Parietal peritoneum and its relief
The innermost layer of the abdominal wall is the parietal peritoneum. On the inner surface of the anterior abdominal wall, it overlies the fascia and tissue, forming a complex relief. This relief is represented by specific folds and fossae, which are of immense importance in operative surgery.
One of the most important structures here is the round ligament of the liver (lig. teres hepatis). This is a peritoneal fold that extends from the umbilical ring upward, heading toward the fissure of the same name on the inferior surface of the liver. Within this fold lies a significant anatomical remnant — the obliterated umbilical vein.
Briefly: answers to topical questions
What anatomical structures make up the spermatic cord?
The spermatic cord consists of a complex of anatomical structures covered by fascial layers. These include:
- Ductus deferens (ductus deferens).
- Blood vessels — testicular artery (a. testicularis), artery and veins of the ductus deferens (a. et vv. deferentiales), cremasteric artery (a. cremasterica), and pampiniform venous plexus (plexus venosus pampiniformis).
- Lymphatic vessels.
- Nerves — genital branch of the genitofemoral nerve (r. genitalis n. genitofemoralis), sympathetic plexuses of the testis and ductus deferens.
- Remnant of the processus vaginalis of the peritoneum.
- Loose connective tissue.
What umbilical folds does the parietal peritoneum form on the anterior abdominal wall?
On the anterior abdominal wall, the parietal peritoneum forms three types of umbilical folds. These include:
- Median umbilical fold (plica umbilicalis mediana) — an unpaired fold extending from the apex of the bladder to the umbilicus, containing the obliterated urachus.
- Medial umbilical fold (plica umbilicalis medialis) — a paired fold containing the obliterated umbilical artery (a. umbilicalis).
- Lateral umbilical fold (plica umbilicalis lateralis) — a paired fold located over the inferior epigastric artery and vein (a. et v. epigastricae inferiores).
What fossae does the parietal peritoneum form in the lower part of the anterior abdominal wall?
Between the umbilical folds, the parietal peritoneum forms depressions that represent weak points of the abdominal wall. The following fossae are distinguished:
- Supravesical fossa (fossa supravesicalis) — located above the urinary bladder, bounded medially by the median umbilical fold and laterally by the medial umbilical fold.
- Medial inguinal fossa (fossa inguinalis medialis) — a paired fossa located between the medial and lateral umbilical folds.
- Lateral inguinal fossa (fossa inguinalis lateralis) — a paired fossa located lateral to the lateral umbilical fold.
Through which fossa on the inner surface of the abdominal wall does the deep inguinal ring project?
The deep inguinal ring projects onto the lateral inguinal fossa (fossa inguinalis lateralis). This paired fossa is located on the inner surface of the anterior abdominal wall lateral to the lateral umbilical fold. From the abdominal cavity, the deep inguinal ring (annulus inguinalis profundus) corresponds precisely to this depression through which indirect inguinal hernias emerge.
To remember the distribution of the transversalis fascia and adipose tissue, imagine the law of gravity: in the upper abdomen, the fascia is thin and there is little adipose tissue; everything "flows" downward—near the inguinal ligament, the fascia becomes a dense fibrous plate, and near the pubic symphysis, a massive layer of preperitoneal tissue accumulates.
Class and exam questions
What separates the transversalis fascia from the parietal peritoneum?
They are separated by a layer of preperitoneal tissue. It is located between the fascial and serous layers.
What is the internal spermatic fascia formed from?
It is a direct continuation of the transversalis fascia (fascia transversalis), which forms a funnel-shaped depression into the inguinal canal.
Where is the preperitoneal tissue best developed?
The greatest accumulation of adipose tissue is observed posteriorly, as well as in the lower part of the anterior abdominal wall near the pubic symphysis.
What does the round ligament of the liver contain?
Within the peritoneal fold that forms the round ligament of the liver (lig. teres hepatis), the obliterated umbilical vein runs.
What else to study on this topic
- Topography and boundaries of the inguinal canal
- Coverings of the spermatic cord and testis
- Relationship of the endoabdominal fascia with the transversus abdominis muscle
- Exact localization and structure of the pubic symphysis
- Formation of folds and fossae on the posterior surface of the anterior abdominal wall
Master the complete topic in the "Topographic Anatomy" course
This is a summary. The course covers everything tested in classes and exams.
- Complete study guide on "Endoabdominal fascia and preperitoneal tissue" and 2,777 more pages of the subject
- Assignments and quizzes after every topic — just like in a colloquium
- AI tutor answers questions on the topic anytime
- 91 video lessons on the subject
Other topics in the section "Topographic Anatomy of the Abdomen"
Free video lessons: topographic anatomyShort lessons with study notes — no registration required.
Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.