Large Intestine: (intro &) Caecum

Question 1

Enumerate the features that differentiate Large intestine from small intestine

Answer 1

• Tenae Coli: they are 3 muscular bands from Vermiform appendix base to end of Sigmoid colon
• Sacculations (Haustrations)
• Appendices epiploicae

Question 2

Different the different arrangement Taeniae coli Across the Large intestine

Answer 2

• Ascending & descending colon: anterior, posteromedial & posterolateral
• Transverse colon: 2 anterior & 1 posterior

Question 3

Explain why large intestine has sacculations/haustrations

Answer 3

due to taeniae coli length being smaller than the length of Colon itself

Question 4

Describe Appendices epiploicae

Answer 4

Small peritoneal projections on the surface of large intestine filled with fat

Question 5

Length of large intestine

Answer 5

150-180 cm long (5 feet)

Question 6

Length of Caecum

Answer 6

5-7 cm

Question 7

Site of Caecum

Answer 7

proximal part of large intestine, located in the right iliac fossa above lateral 1/2 of Right inguinal ligament

Question 8

Desrcibe surface anatomy of Caecum

Answer 8

Lies within a triangle bounded by:
* lateral 1/2 of Inguinal Ligament
* Righ midclavicular plane (vertically)
* Intertubercular Plane (horizontally)

Question 9

Enumerate Caecal Orificies

Answer 9

1. Ileocaecal Orifice: posteromedial aspect of upper part of caecum
2. Orifice for Vermiform appendix: Posteromedial aspect of Caecum, 1 inch below and lateral to Ileocaecal Orifice (valve)
3. Colic Orifice: continuous with ascending colon

Question 10

Describe the Formation of Ileocaecal Valve

Answer 10

Enterance of Ileum into the caecum forms 2 lips (upper and lower) which will meet medial & lateral to form 2 horizontal ridges above one another that make up the Valve frenula

Question 11

Importance of Ileocaecal valve

Answer 11

prevents reflux of of Caecal content back into ileum by contraction of Circular Muscles of Ilium which pulls the Frenula and closes the valve

Question 12

Anterior relations of Caecum

Answer 12

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

Question 13

Posterior relations of the Caecum

Answer 13

3 muscles:
* Psoas Major
* Psoas Minor
* Iliacus

3 Nerves:
* Femoral N
* Genitofemoral N
* Lat. Cutaneous N of thigh

3 Vessels:
* External Iliac A
* Gonadal A
* Gonadal V

all of the above are Right (right gonadal A, right Iliacus, etc)

Question 14

Arterial Supply of Caecum

Answer 14

Anterior & Posterior Caecal A: from Ileocolic A from Sup. Mesenteric A

Question 15

Venous Drainage of Caecum

Answer 15

Caecal Veins which drain into Sup. mesenteric V (portal circulation)