Class 3 - Station 1: Gut Tube part 2 - Small & Large Intestine, Rectum and Anal Canal

Question 1

What are the 3 parts of the small intestine?

Answer 1

Duodenum

Jejunum

Ileum

Question 2

Which part of the small intestine recieves the opening for the bile and pancreatic duct?

Answer 2

2nd part of the duodenum at the ampulla of vater.

Question 3

Where is the midgut-foregut boundary?

Answer 3

Just inferior to the ampulla of vater.

Question 4

How is the duodenum peritonised?

Answer 4

Retroperitoneal

Question 5

How is the jejunum peritonised?

Answer 5

Intraperitoneal

Question 6

How is the ileum peritonised?

Answer 6

Intraperitoneal

Question 7

What are the differences between the jejunum and the ileum?

Answer 7

write this out

Question 8

What are arterial arcades?

Answer 8

Arterial loops and arches

Question 9

Which part of the small intestine has many small arterial arcades?

Answer 9

Ileum

Question 10

Which of the autonomic divisions acts as a motility reducer and a vasocontrictor on the small intestine?

Answer 10

Sympathetic

Question 11

What is the path of the sympathetic to the small intestine?

Answer 11

Greater splanchnic nerves T5 to L1/2

Leading to superior mesenteric ganglion and coeliac ganglion

Question 12

How can the large intestine be differentiated from the small intestine?

Answer 12

• Taeniae coli
• Haustra
• Epiploic appendages

Question 13

What are taenia coli and what innervates them?

Answer 13

Longitudinal muscle that contracts to form the haustra.

Innervated by pelvic parasympathetic nerves.

Question 14

What are haustra?

Answer 14

• Sacculations in the colon
• When they fill they distent and then contract to move chyme through the colon

Question 15

What are epiploic appendages?

Answer 15

Small pockets of fat in the surrounding peritoneum

Question 16

How is the caecum peritonised?

Answer 16

Intraperitoneal

Question 17

How is the ascending colon peritonised?

Answer 17

Retroperitoneal

Question 18

How is the transverse colon peritonised?

Answer 18

Intraperitoneal

Question 19

How is the descending colon peritonised?

Answer 19

Retroperitoneal

Question 20

How is the sigmoid colon peritonised?

Answer 20

Intraperitoneal

Question 21

Hint: LOOK AT WHERE THEY SUPPLY

Answer 21

1. SMA
2. Middle colic artery
3. Marginal artery
4. Right colic artery
5. Iliocolic artery
6. Appendicular artery
7. Middle rectal artery
8. Superior rectal artery
9. Sigmoidal arteries
10. Left colic
11. IMA

Question 22

Where is the midgut/hindgut boundary?

Answer 22

2/3rds distally down the transverse colon (note the blood supply)

Question 23

In what abdominal region is the caecum and appendix?

Answer 23

Right Iliac Fossa (rec. Macburney’s point)

Question 24

What two structrures open into the cavity of the caecum?

Answer 24

Ileal orifice

Orifice of veniform appendix

Question 25

What is Macburney's point?

Answer 25

Site of greatest intensity of pain in appendicitis - commonly located between the appendix and umbilicus

Question 26

What is the arterial supply and venous drainage of the superior 1/3rd of the rectum? And the peritonisation

Answer 26

- Superior rectal artery - Superior rectal vein Retroperitoneal

Question 27

What is the arterial supply and venous drainage of the middle 1/3rd of the rectum? And the peritonisation

Answer 27

- Middle rectal artery - Middle rectal vein Retroperitoneal

Question 28

What is the arterial supply and venous drainage of the inferior 1/3rd of the rectum? And the peritonisation

Answer 28

- Inferior rectal artery - Inferior rectal vein Extraperitoneal

Question 29

Answer 29

2. Gastric veins 3. Portal vein 4. Superior mesenteric vein 5. Colic veins 7. Appendicular 8. Inferior and middle rectal veins 9. Superior rectal veins 10. Sigmoidal veins 11. Left colic veins 12. Inferior mesenteric vein 13. Splenic vein 14. Oesophageal veins

Question 30

Identify the superior, middle and inferior rectal folds

Answer 30

The folds of mucosa

Question 31

What is the function of the rectal folds?

Answer 31

Support faeces so as they don't constantly infringe on the internal anal sphincter

Question 32

What is the role of the internal and external sphincters?

Answer 32

Internal (above pectinate line) - visceral nerve supply, when rectum is full this relaxes so that faeces put pressure on the external External (below pectinate line) - somatic control, can be opened to allow defacation

Question 33

What arteries supply the anus below the pectinate line?

Answer 33

Branches of the internal iliac arteries

Question 34

What is the venous drainage of the anus below the pectinate line?

Answer 34

Into the porto caval anastomosis to enter the portal system

Question 35

What is the lymphatic drainage of the anus below the pectinate line?

Answer 35

Superficial inguinal lymph nodes