Introduction

Question 1

Describe the functions of the mouth. (3)

Answer 1

Physical breakdown of food.
Initial amylases and lipases released
Infection control

Question 2

Describe the functions of the oesophagus. (3)

Answer 2

Rapid peristalsis of the bolus through the the thorax.
UOS prevents air entering GI tract.
LOS prevents helps prevent reflux.

Question 3

Describe the functions of the stomach. (4)

Answer 3

Temporary storage
Physical and chemical breakdown. 
Infection control (HCl)
Secrete intrinsic factor (Vitamin B12)

Question 4

Describe the functions of the duodenum. (2)

Answer 4

Neutralisation of chyme.

Pancreatic and gallbladder secretions.

Question 5

Describe the functions of the jejunum. (1)

Answer 5

Nutrient absorption.

Question 6

Describe the functions of the ileum. (4)

Answer 6

Final digestion with very large SA
Water and electrolyte absorption
Bile recirculating
Terminal: B12 absorption

Question 7

Describe the functions of the large bowel. (3)

Answer 7

Final water absorption against gradient
Final electrolyte absorption
Temporary storage

Question 8

Describe the functions of the rectum and anus. (1)

Answer 8

Defication following ‘mass movement’.

Question 9

Describe the parasympathetic nervous system in GI control. (3)

Answer 9

The ‘on’ button of the GI tract through vagus and pelvic splanchinic nerves in the cranosacral outflow.

Question 10

Describe the sympathetic nervous system in GI control. (4)

Answer 10

The ‘off’ button of the GI tract though constriction of blood vessels. Forms greater, lesser and least splanchnic nerves from thoracolumbar outflow.

Question 11

Describe the enteric nervous system. (6)

Answer 11

Operates independently, but can work with ANS.
Two plexi - Submucosal (Meissner’s) and Myenteric (Auerbach’s - between circular and longitudinal muscle).
Submucosal - secretions and blood flow, myentric - motility.

Question 12

Describe the peritoneal cavity (3)

Answer 12

The imagined space between the parietal peritoneum that is adhered to the abdominal wall, and the visceral peritoneum that is adhered to all the organs; filled with a tiny bit of lubricating fluid.

Question 13

Describe the branches of the coeliac trunk. (4)

Answer 13

Three branches which join.
Splenic links with common hepatic through gastroduodenal.
Common hepatic links with left gastric through right gastric.

Question 14

Describe the branches of the SMA. (4)

Answer 14

Jejunal and ileal anastomoses
Ileocolic
Right colic
Middle colic

Question 15

Describe the branches of the IMA. (3)

Answer 15

Left colic
Sigmoid
Superior rectal.