Caecum

Question 1

Caecum

Answer 1

Large intestine proximal part

Question 2

Size

Answer 2

5-7 cm long

Question 3

Site

Answer 3

1. Lies in right iliac fossa above lateral 1/2 of right Inguinal ligament
2. Closed inferior and continuous above with ascending colon

Question 4

Surface anatomy

Answer 4

Lies in triangular area bounded by:
1. Lateral 1/2 of right Inguinal ligament
2. Intertubercular plane
3. Right midclavicular line

Question 5

Caecal orifices

Answer 5

1. Ileocaecal orifice
2. Vermiform appendix
3. Colic orifice

Question 6

Ileocaecal orifice

Answer 6

Opens into Posteromedial aspect of caecum upper end where it is guarded by ileocaecal valve

Question 7

Ileocaecal valve

Answer 7

Ileum enters obliquely through horizontal slit into caecum Posteromedial wall forming 2 folds (upper and lower) which meet medial and lateral in 2 ridges forming valve frenula

Question 8

Caecal contents reflux into ileum is prevented by:

Answer 8

1. Contraction of ileum circular muscle
   2 frenula tightening
   This draws valve lips together closing orifice

Question 9

Vermiform appendix

Answer 9

Opens into caecum Posteromedial aspect 1 inch below and lateral to ileocaecal valve

Question 10

Colic orifice

Answer 10

Caecum upper end is continuous with ascending colon

Question 11

Peritoneal covering and recesses

Answer 11

Nearly completely covered by peritoneum but has no mesentery

Question 12

3 recesses are related to Ileocaecal junction

Answer 12

1. Superior Ileocaecal recess
2. Inferior Ileocaecal recess
3. Retrocaecal recess

Question 13

Superior ileocaecal recess

Answer 13

1. Under a peritoneal fold (caecum vascular fold) which lodges anterior Caecal artery
2. Folds extends from lowermost part of small intestine mesentery to caecum front
3. Recess opening looks downwards and to left

Question 14

Inferior ileocaecal recess

Answer 14

1. Under peritoneal fold (ileocaecal fold or Treves bloodless fold) which extends from ileum end to caecum front
2. Recess opening looks downwards and to left

Question 15

Retrocaecal recess

Answer 15

1. Behind caecum and may extend upwards behind ascending colon (retrocolic recess)
2. Contains appendix in 75% of cases
3. Opening looks downwards

Question 16

Relations

Answer 16

1. Anterior
2. Posterior

Question 17

Anterior relations

Answer 17

1. Anterior abdominal wall
2. Greater omentum
3. Small intestine

Question 18

Posterior relations

Answer 18

3 muscles:
1. Psoas major
2. Psoas minor
3. Iliacus
3 nerves:
1. Genitofemoral
2. Femoral
3. Lateral cutaneous nerve of thigh
3 vessels:
1. External iliac artery
2. Right gonadal artery
3. Right gonadal vein

Question 19

Arterial supply

Answer 19

Anterior and posterior Caecal arteries branches of ileocolic artery (branch of superior mesenteric artery)

Question 20

Venous drainage

Answer 20

Caecal veins into superior mesenteric vein (portal circulation)