QS Study

Caecum – It is a large blind sac forming the commencement of the large intestine. It provides a space for the mixing of bacteria with partially digested food from the small intestine to form feces. It is the first part of the large bowel and lies in the right lower quadrant of the abdomen

The caecum functions as a guide to the surgeon during surgery for intestinal obstruction.

  • Situation – In the right iliac fossa, above the lateral half of the inguinal ligament.
  • Length – 6 cm long.
  • Breadth – 7.5 cm broad.

Communications

  • Superiorly – with ascending colon.
  • Medially – with ileum.
  • Posteromedially – with appendix.

Types –

(1) Conical (13%) – The caecum is conical and the appendix is connected at its apex.

(2) Intermediate (9%) – The caecum is quadrate in shape and the appendix is connected in the depressed underside.

(3) Ampullary (78%) – The right saccule is bigger in relation to the left and the appendix is connected on the posteromedial aspect about 2 cm below the ileocaecal junction.

Fig: Different forms of Caecum

Relations:

(A) Anterior –

  1. Coils of the intestine,
  2. Anterior abdominal wall.

(B) Posterior –

  1. Right psoas K iliacus.
  2. Nerves (genito-femoral, femoral & Lat. cut. acne of thigh)
  3. Vessels (testicular or ovarian),
  4. Appendix.

Blood supply:

  • The caecum is supplied by the anterior and posterior caecal branches of the ileocolic artery,
  • The veins of the caecum follow the arteries and drain into the superior mesenteric vein,
  • The lymph vessels from the caecum drain into the ileocolic lymph nodes.

Nerve supply

(A) Sympathetic – T11 to L1.

(B) Parasympathetic – Vagus nerve.

Interior

(i) Ileocaecal orifice: Situated in the posteromedial wall of the junction of the caecum and ascending colon. It is guarded by a valve.

(ii) Appendicular orifice: Situated 2 cm below and behind the ileocaecal orifice.

Development: From Caecum bud, arising from post arterial segment of the midgut loop.