APPENDIX

 

APPENDIX (Aan~pucC)

INTRODUCTION:

This is a worm like Diverticulum arising from the posteromedial wall of the Caecum.

LENGTH:

·        Average length- 9 c.m.

·        It is 5mm in diameter.

·        It is longer in children than in adults.

·        The lumen is quite narrow and may be obliterated after mid-adult life.

POSITONS:

It lies in the Right Iliac Fossa. The base of the Appendix is fixed. The tip of the Appendix can point in any of the following directions-

·        11 o’clock or PARACOLIC POSITION (Upwards and Right)

·        It may lie behind the Caecum or Colon (RETROCECAL or 12 o’clock position). This is the most commonest position of the Appendix (about 65%)

·        2 o’clock or SPLENIC POSITION. The Appendix enters upward and medially (Pre-ileal) or (Post-ileal).

·        3 o’clock or PROMONTORIC position.

·        4 o’clock or PELVIC position. This is the second most common position of the Appendix (about 30%).

·        SUBCAECAL or MIDINGUINAL or 6 o’clock position.

APPENDICULAR ORIFICE:

·        It is situated 2cm below the ILEOCAECAL ORIFICE.

·        The appendicular orifice is occasionally guarded by an indistinct semilunal fold of mucus membrane, known as “Valve of Gerlach”.

·        The Orifice is marked on the surface by a point situated 2cm below the junction of TRANSTUBERCULAR and RIGHT LATERAL Planes.

PERITONEAL RELATIONS:

The Appendix is suspended by a small triangular fold of Peritoneum, called the MESOAPPENDIX.

BLOOD SUPPLY:

The APPENDIULAR ARTERY is a branch of the Lower Division of the ILEOCOLIC ARTERY.

NERVE SUPPLY:

·        Sympathetic Nerves are derived from segments T9 to T10 through the Coeliac Plexus

·        Parasympathetic Nerve supply by the Vagus Nerve.

 

APPLIED ANATOMY:

·        APPENDICITIS - Inflammation of the Appendix is known as Appendicitis.

·        APPENDICECTOMY -   The operation for the removal of the Appendix is called Appendicectomy.

·        STEPS -

1.      Progression Of Pain-

§  Pain is first felt in the region of the Umbilicus. This is a referred pain.

§  With increasing inflammation pain is felt in the Right Iliac Fossa.

2.      Sign-

§  MC Burney’s Point is the site of maximum tenderness in Appendicitis (Base of Appendix).

§  The point lies at the junction of the lateral 1/3^rd and medial 2/3^rd of the line joining the Umbilicus to the Right Anterior Superior Iliac Spine.

 

3.      Diagnosis  Of the Position of Appendix-

§  When the Appendix is RETROCAECAL, extension of the hip joint may cause pain because the Appendix is disturbed by stretching of the Psoas Major Muscle.

§  In Pelvic Appendicitis, pain may be felt when the thigh is flexed and medially rotated because the Obturator Internus muscle is stretched.