Small and Large Intestine

Question 1

What is the length of the small intesting

Answer 1

6-7m long

Question 2

What is the location of the jejunum and duodenum

Answer 2

Jejunum : mostly left upper quadrant

Ileum: Mostly in right lower quadrant

Question 3

Explain the difference in vascularity patterns between the jejunum and ileum

Answer 3

Jejunum:

• More vascular
• Long and few Vasa Recta and Arcades

Ileum:

• Less vascular
• Short and many Vasa Recta and Arcades

Question 4

Between jejunum and ileum, which has the most fat in the peritoneum

Answer 4

Ileum

Question 5

Between jejunum and ileum, explain the difference in Circular Folds (Plica Circulares)

Answer 5

Jejunum:
Large, tall and closely packed

Ileum:
Low and sparse, absent in distal part

Question 6

Between jejunum and ileum, which has more Lymphoid Nodules (Peyer’s Patches)?

Answer 6

Ileum

Question 7

What is the blood supply of the Jejunum and Ileum?

Answer 7

Arterial:
-Jujuneal and ileal braches from SMA. These form arterial arcades

Venous:
-Accompany arteries and drain into SMV. Later drains into Portal Vein.

Question 8

What is the lymphatic drainage of the Ileum and Jejunum?

Answer 8

Superior Mesenteric LN

Question 9

What is the nerve supply to the Jejunum and Ileum

Answer 9

Vagus and Thoracic Splanchnic Nerves (Via celiac and superior mesenteric plexuses)

Question 10

What is the length of the large intestine

Answer 10

1.5m

Question 11

Explain the small fat-filled sacs of peritoneum in the large intestine

Answer 11

Called Omental Appendices

Not present in Cecum, Vermiform Appendix and Rectum

Question 12

What are the muscle fibres of the large intestine? How are they arranged?

Answer 12

Taenia Coli
Longitunidal muscle fibres arranged in 3 bands
Not present in Appendix or Rectum

Question 13

What is formed from the Taenia Coli being shorter than the intestine?

Answer 13

Haustral or Sacculations

Question 14

What are the parts of the Large Intestine

Answer 14

Cecum and Appendix

Colon:

• Ascending
• Transverse
• Descending
• Sigmoid

Rectum

Anal Canal

Question 15

What is the position of the Ascending Colon and Rt. Colic Flexure

Answer 15

Rt Lumbar Region and Rt .Hypocondriac Region
Lateral to Rt MCL

Rt Colic Flexure:
-In upper and right angle of intersection of subcostal and rt. MCL

Question 16

What is the position of the transverse Colon

Answer 16

Between Umbilical and Epigastric regions
From Rt. Hypocondriac through till Lt. Hypocondriac Regions

Lower border is one level above Umbilicus
Upper border just below greater curvature of stomach

Question 17

What is the position of the Descending Colon and the Lt. Colic Flexure?

Answer 17

Lt. Lumbar Region, Lateral to Lt. MCL as far as Iliac Crest (at Pelvic Inlet)

Lt Colic Flexure:
Upper Lt. angle of intersection between Lt. MCL and Transpyloric lines

Question 18

What is the position of the Sigmoid Colon

Answer 18

From end of Descending Colon (pelvic brim) to Lt. MCL at level of ASIS.

From Pelvic Brim, crosses Sacrum and curves to midline to 3rd sacral vertebra at rectum.

Question 19

What is the location of the Caecum

Answer 19

Rt. Iliac Fossa, above Inguinal Ligament.

Completely covered by Peritoneum

Question 20

How big is the Caecum?

Answer 20

6-7cm in length and breadth

Question 21

Explain the structure of the Ileocecal Valve

Answer 21

AKA the ILV

Has an upper and lower lip which fuse at either side - forming the Frenulum of the Valve

Question 22

What is the length of the Vermiform Appendix

Answer 22

8cm

Question 23

Where does the Appendix arise?

Answer 23

Posteromedial wall of Cecum, 2cm below Ileocecal valve

McBurney’s Point:
The base lies at a point 1/3 the distance from the right ASIS to Umbilicus

Question 24

What is the ligament of the Appendix? What does it contain?

Answer 24

Meso-appendix

Contains Appendicular Artery

Question 25

How is the appendix related to the peritoneum

Answer 25

Intraperitoneal

Question 26

What are the variable positions of the appendix?

Answer 26

Retro-caecal (retro-colic)
Subcaecal
Pre-ileal
Retro-ileal (post-ileal)

Question 27

What is the relationship of the ascending colon to the peritoneum

Answer 27

Retroperitoneal - Peritoneum covers anterior and lateral surfaces

Question 28

What is the relationship of the transverse colon to the peritoneum? Explain the relations of the Transverse mesocolon.

Answer 28

Completely intraperitoneal

Transverse mesocolon passes ant. to pancreas

Question 29

What is the relationship of the Descending colon to the peritoneum

Answer 29

Retroperitoneum

Question 30

What is the relationship of the Sigmoid Colon with the peritoneum

Answer 30

Forms a loop hanging into pelvis with mesosigmoid

Entirely Intraperitoneal

Question 31

What is the blood supply to the Large Intestine

Answer 31

SMA:

• Caecum (Ileocolic a)
• Appendix (Appendicular a)
• Ascending colon (Right Colic a)
• Proximal 2/3 of Transverse Colon (Middle Colic a)

IMA:

• Distal 1/3 of Transverse colon (Left Colic a)
• Descending Colon (Left Colic a)
• Sigmoid Colon (Sigmoidal a)
• Rectum (Superior Rectal a)

Question 32

What is the venous drainage of the Large Intestine

Answer 32

SMV and IMV - finally draining into Portal Vein

Question 33

What is the nerve supply to the Large Intestine?

Answer 33

Midgut derivatives:

• Coeliac plexus
• Superior mesenteric plexus

Hindgut derivatives:

• Superior hypogastric plexus
• Pelvic Splanchnic Nerves

Question 34

What is the Lymphatic Drainage of the Large Intestine?

Answer 34

Caecum and Appendix:
-Ileocolic LN

Ascending colon

• Epiploic LN
• Paracolic LN

Transverse colon
-Middle colic LN

Descending and Sigmoid colon:
-Intermediate colic LN

Question 35

What is an Intussusception

Answer 35

When there is ‘telescoping’ of the small intestine

Question 36

What is a volvolus

Answer 36

An obstruction due to twisting or knotting of the gastrointestinal tract

Mesentary holding intestines is abnormally large