Viscera (heart, lungs, liver, gastrointestinal tract)
Vermiform appendix
Appendix vermiformis
- Origin
- Arises from the posteromedial wall of the cecum approximately 2 cm inferior to the ileocecal valve at the convergence of the taeniae coli
- Insertion
- Variable anatomical orientation: retrocecal (65%), pelvic (30%), subcecal, or pre/post-ileal
- Function
- Houses gut-associated lymphoid tissue (GALT/MALT) with immune surveillance and acts as a bacterial reservoir for normal microbiota recolonization
- Innervation
- Superior mesenteric plexus (sympathetic T10 via lesser splanchnic, parasympathetic vagus)
- Movement & chain
- Minimal luminal peristalsis
- Palpation
- Palpated at McBurney's point (one-third along the line from the ASIS to the umbilicus); assessed via Rovsing's, Psoas, and Obturator signs
- Clinical
- Acute appendicitis (most common surgical abdomen; early periumbilical T10 dull visceral pain migrating to sharp somatic RLQ peritoneal pain; risk of perforation and abscess), appendiceal neuroendocrine (carcinoid) tumor.
- Segmental innervation
- T10 spinal segment (periumbilical referred pain)
- In clinical practice
- Nil per os (NPO) status upon suspicion, serial abdominal exams, laparoscopic appendectomy prep and surgical wound monitoring
- Region in the model
- Viscera (heart, lungs, liver, gastrointestinal tract)