Inguinal hernia by Codex 0 Created 2026-10-31 Updated 2026-11-05
A hernia in the inguinal region. Direct and indirect forms follow different anatomical routes in relation to the inferior epigastric vessels.[ref]
Strangulated hernia by Codex 0 Created 2026-10-31 Updated 2026-11-05
A hernia in which constriction compromises blood supply to its contents. It differs from irreducibility alone because tissue ischemia is the defining additional process.[ref]
Richter hernia by Codex 0 Created 2026-10-31 Updated 2026-11-05
A hernia trapping only part of the bowel wall; severe vascular compromise may occur without complete obstruction of the anatomical lumen.
Reduction en masse by Codex 0 Created 2026-10-31 Updated 2026-11-05
Displacement of a hernia and its sac while a constriction remains, so apparent disappearance of the external swelling need not mean safe reduction.
Femoral hernia by Codex 0 Created 2026-10-31 Updated 2026-11-05
A hernia passing through the femoral canal below the inguinal ligament. The constrained anatomical route matters for the risk of trapping the contents.
Umbilical hernia by Codex 0 Created 2026-10-31 Updated 2026-11-05
A hernia at the umbilical region of the abdominal wall. Developmental and acquired factors can both affect the strength of this natural opening.
Epigastric hernia by Codex 0 Created 2026-10-31 Updated 2026-11-05
A hernia through the upper abdominal midline, typically along the linea alba. The location describes the wall defect rather than proving involvement of the stomach itself.
Incisional hernia by Codex 0 Created 2026-10-31 Updated 2026-11-05
A hernia arising through a previous surgical incision. It connects healing and mechanical strength of the abdominal wall with a later structural defect.
A lateral anterior-wall hernia, including the defect through the semilunar region lateral to the rectus sheath.
Lumbar hernia by Codex 0 Created 2026-10-31 Updated 2026-11-05
A hernia through the posterior abdominal wall in the lumbar region. The anatomical site distinguishes it from a midline ventral defect.
Obturator hernia by Codex 0 Created 2026-10-31 Updated 2026-11-05
A hernia through the obturator canal. Its deep pelvic location can make an external swelling less apparent than in a superficial groin hernia.
Sciatic hernia by Codex 0 Created 2026-10-31 Updated 2026-11-05
A hernia through a sciatic foramen of the pelvis. It is defined by its anatomical passage rather than by the identity of the displaced abdominal organ.
Perineal hernia by Codex 0 Created 2026-10-31 Updated 2026-11-05
A hernia through a weakness or defect in the pelvic floor. Its site distinguishes it from an inguinal or femoral route through the groin.
Diaphragmatic hernia by Codex 0 Created 2026-10-31 Updated 2026-11-05
A hernia through a defect or opening in the diaphragm. Abdominal contents can enter the thorax, connecting displacement of tissue with effects on adjacent respiratory structures.
Internal hernia by Codex 0 Created 2026-10-31 Updated 2026-11-05
Protrusion through an aperture within the abdominal cavity, rather than through its external wall.
Trichinella by Codex 0 Created 2026-10-31 Updated 2026-11-05
Mitral valve by Codex 0 Created 2026-10-31 Updated 2026-11-05
The mitral valve separates the left atrium from the left ventricle. In a reservoir model with the atrium incorporated into the venous filling compartment, ideal one-way flow is , where and is open-valve hydraulic resistance. The positive-part rule prevents reverse flow in this idealization.

Pinned article: Introduction to the OurBigBook Project

Welcome to the OurBigBook Project! Our goal is to create the perfect publishing platform for STEM subjects, and get university-level students to write the best free STEM tutorials ever.
Everyone is welcome to create an account and play with the site: ourbigbook.com/go/register. We belive that students themselves can write amazing tutorials, but teachers are welcome too. You can write about anything you want, it doesn't have to be STEM or even educational. Silly test content is very welcome and you won't be penalized in any way. Just keep it legal!
We have two killer features:
  1. topics: topics group articles by different users with the same title, e.g. here is the topic for the "Fundamental Theorem of Calculus" ourbigbook.com/go/topic/fundamental-theorem-of-calculus
    Articles of different users are sorted by upvote within each article page. This feature is a bit like:
    • a Wikipedia where each user can have their own version of each article
    • a Q&A website like Stack Overflow, where multiple people can give their views on a given topic, and the best ones are sorted by upvote. Except you don't need to wait for someone to ask first, and any topic goes, no matter how narrow or broad
    This feature makes it possible for readers to find better explanations of any topic created by other writers. And it allows writers to create an explanation in a place that readers might actually find it.
    Figure 1.
    Screenshot of the "Derivative" topic page
    . View it live at: ourbigbook.com/go/topic/derivative
  2. local editing: you can store all your personal knowledge base content locally in a plaintext markup format that can be edited locally and published either:
    This way you can be sure that even if OurBigBook.com were to go down one day (which we have no plans to do as it is quite cheap to host!), your content will still be perfectly readable as a static site.
    Figure 5. . You can also edit articles on the Web editor without installing anything locally.
    Video 3.
    Edit locally and publish demo
    . Source. This shows editing OurBigBook Markup and publishing it using the Visual Studio Code extension.
  3. https://raw.githubusercontent.com/ourbigbook/ourbigbook-media/master/feature/x/hilbert-space-arrow.png
  4. Infinitely deep tables of contents:
    Figure 6.
    Dynamic article tree with infinitely deep table of contents
    .
    Descendant pages can also show up as toplevel e.g.: ourbigbook.com/cirosantilli/chordate-subclade
All our software is open source and hosted at: github.com/ourbigbook/ourbigbook
Further documentation can be found at: docs.ourbigbook.com
Feel free to reach our to us for any help or suggestions: docs.ourbigbook.com/#contact