Intro , Purpose Of Gut

Question 1

What is the purpose of the GI system ?

Answer 1

• entry for food
• mechanically disrupt food
• temporarily store
• chemically digest
• kill pathogens
• move food
• absorb water and nutrients
• expel waste product

Question 2

Name the different parts of the GI tract

Answer 2

Mouth,Oesophagus,Stomach,Duodenum,Jejunum,Ileum,Caecum,Ascending,Transverse,Descending,Sigmoid,Rectum,Anal canal

Question 3

What are the areas involved in mechanical disruption ?

Answer 3

Mouth

Stomach

Question 4

What are the storage areas of the GI ?

Answer 4

Stomach :distend (rugae) and relax

Colon (transverse and descending)

Question 5

State the areas involved in chemical digestion and how ?

Answer 5

Saliva : amylase , lipase
Stomach : acids , pepsin
Duodenum/jejunum : Bile, exocrine section from pancreas

Question 6

How does the GI system prevent entry of pathogens ?

Answer 6

Epithelium
Saliva has IgA
Acid
Kupffer cells from liver
Peyers patches : lymphoid follicles in mucosa in intestines

Question 7

What structural features of the gut aid absorption ?

Answer 7

Length
Folds (rugae and plicae circulares )
Villi/microvilli

Question 8

What are the broad functions of the mouth ?

Answer 8

Physical disruption, digestion,infection control

Question 9

What are the broad functions of oesophagus ?

Answer 9

Rapid transport of bolus to stomach,
Upper sphincter prevents air in GI
Lower sphincter prevents reflux

Question 10

What are the broad functions of the stomach ?

Answer 10

Storage, infection control
Produce chyme : physical ,chemical breakdown,digestion
Secretion of Intrinsic Factor

Question 11

What are the broad functions of the duodenum ?

Answer 11

Neutralisation and osmotic stabilisation of chyme : HCO3 secretions
Digestion : pancreatic secretion, bile

Question 12

What are the broad functions of the Jejunum ?

Answer 12

Final digestion

Nutrient absorption

Question 13

What are the broad function of the ileum ?

Answer 13

Final digestion
Water and electrolytes absorption
B12 absorption
Bile recirculating

Question 14

What are the broad functions of the large bowel ?

Answer 14

Water reabsorption ( Aquaporines , not paracellularly due to tight junction )
Electrolyte reabsorption

Question 15

What is the peritoneal cavity ?

Answer 15

Space between parietal and visceral peritoneum

Question 16

What are the embryonic origins of the peritoneal layers ?

Answer 16

Parietal : somatic

Visceral : splanchnic

Question 17

What is the mesentery ?

Answer 17

Double fold of peritoneum that supports the intra peritoneal viscera and attaches it to the posterior abdo wall and allows conduit for vessels

Question 18

What lies behind the root of the mesentery ?

Answer 18

Peritoneum

Question 19

What are peritoneal recesses ? Name 4

Answer 19

Areas of peritoneal cavity where pathological fluids can collect or channels that allow fluid to move

• Vesicouterine pouch
• Rectouterine pouch (of Douglas )
• Rectovesical pouch
• Paracolic gutters

Question 20

What is the greater omentum ?

Answer 20

Double folds of peritoneum (attached to stomach ) connecting structures together or to the abdominal wall and covering the bowels

Question 21

What is the lesser omentum ?

Answer 21

Double layer of peritoneum extending from lesser curvature of stomach to liver

Question 22

What are the layers of the abdominal wall ?

Answer 22

Skin
Superficial fascia 
Investing fascia 
Abdominal muscles : external oblique, internal oblique , transversus abdominis , rectus abdominis 
Transversalis fascia 
Peritoneum