Anatomy of Appendix

Al-Momtan Ahmed T.

C2

Supervised by:

Dr. Ghazi Qasaimeh

Why are we here?• We are here to find an answer for the following question…

Where is the disease?

•the disease is in here!!

•Although the pain may begin in here!

Abdomenal Regions

• Mid-clavicualr Lines.• Transpyloric plane• Transtubercular plane.• 4 regions anatomy Vs. 9 regions

An Idea about the surgical Incisions• McBurney Grid Iron (muscle-split incision)• McBurney Grid Ieon (muscle split incision)

first described in 1894 by Charles McBurney

For most Appendectomies.

Made at the junction of the middle third and outer thirds of a line running from the umbilicus to the anterior superior iliac spine. (The McBurney Point)

The level and the length of the incision vary according to: The thickness of the abdominal wall. The suspected position of the appendix.

if palpation reveals a mass, the incision can

be placed directly over the mass.

McBurney’s Point and Incision

• Advantages:- Good healing.

- Cosmetic appearance.

- Negligible risk of herniation.

Abdominal Wall1-Layers of Abdominal wall:

SkinSuperficial fascia : (Camper’s [fatty] and Scarpas [membranous] fascia)Deep fascia ( CT fascia)MusclesTransversalis fasciaExtraperitoneal fasciaPeritoneum

Anterior Group Lateral Group

Rectus abdominis External oblique

Pyramidalis Internal Oblique

Transversus Abdmominis

2- Muscles of abdominal wall:

Vermiform Appendix

• Narrow, vermin (worm shaped) tube, arises from the posteriomedial caecal wall.

• Can be found in different positions in relation to the surrounding viscera; can be:

- retrocaecal,retrocolic, pre-ileal, post-ileal, pelvic…- Different location, different pain!!?

2%32%64%

0.5%

Clinical importance of appendicular location..

• Exceptions exist in the classic presentation due to anatomic variability of the appendix

• Appendix can be retrocaecal causing the pain to localize to the right flank

• In pregnancy, the appendix ca be shifted and patients can present with RUQ pain

• In some males, retroileal appendicitis can irritate the ureter and cause testicular pain.

• Pelvic appendix may irritate the bladder or rectum causing suprapubic pain, pain with urination, or feeling the need to defecate

• Multiple anatomic variations explain the difficulty in diagnosing appendicitis

- Pain exacerbation of appendicitis gets worse with rotation medially and laterally in case of appendix lying against obturator internis muscle.

Cont.• The 3 taenia coli of in the ascending colon and caecum converge on the base of

the appendix and merge into its longitudinal muscle.

• The ant caecal taenia is usually distinct and can be traced to the appendix, which affords a guide to its location in clinical practice.

• Appendix length can vary from 2 to 20 cm in length, relatively longer in children and may atrophy and shorten after mid-adult life.

Cont.

• Its connected by a short mesoappendix to the lower part of the ileal mesentry.

• Small lumen, opens into the caecum by an orifice lying bellow and slightly posterior to the iliocaecal junction, sometimes this orifice is guarded by a semilunar mucosal fold forming a valve!

• The lumen may be widely patent in early childhood, and often partially or wholly obliterated in th elater decades of life.

• It contains numerus patches of lymphoid tissue although these tend to decrease in size from early adulthood (carcinoid!!?).

:D its notcolourful in here ;)

Blood Supply of the Appendix• Appendicular artery and veinS..

• The appendicular artery is a branch from the lower division of the ileocolic artery, runs behind the terminal ileum and enters the mesoappendix a short distance from the appendicular base. Here it gives off a recurrent branch, which anastomoses with a branch from the posterior caecal artery.

• The main artery approches the tip of the appendix, this one may be thrombosed in appendicitis >> gangrene and infarction.

• SMA Rt colic and ileocolic ileiocolic gives ant and post caecal post caecal appendicular.

• Veins: one or more veins into the post

caecal or ileocolic vein and thence into

the superior mesenteric vein.

Lymphatics

• They are numerous, as there is abundant lymphoid tissue in its walls.

• From the body and apex of the appendix 8-15 vessels ascend in the mesoappendix and are ocasionally intrupted by one or mote nodes >> unite to form 3 or 4 larger vessels >> inf and

superior nodes of the ileocolic

chain.

Innervation• Sympathetic and parasympathetic nerves from th

esuperior mesenteric plexus.• Visceral afferent fibers carrying sensation of stretch and

distention mediate the symptoms of “pain” felt during the initial stages of appendicular inflammation.

• With the other structures derived from the midgut, these sensations are poorly localized initially and referred to the central (pericumblical) region of the abdomen.

• Localized pain occurs when parietal tissues are involved >> somatic ..

Functions of Vermiform Appendix

• general good health of people who have had their appendix removed or who have a congenital absence of an appendix may tell that “The appendix is traditionally thought to have no function in the human body. There have been no reports of impaired immune or gastrointestinal function in people without an appendix”

• Some might say; it secretes special type of mucus, IgA rich mucus, which works as anti-harmful bacterial agent.

• Others suggest it’s a housekeeper of the good bacteria.

Thank you..!

• End of my Part,

• Moataz will contimue with the clinical Picture>>>>