GI

Question 1

Purpose of the gut (8)

Answer 1

Port of entry for food
Mechanically disrupt food
Temporary food storage
Chemically digest food
Kill pathogens on food
Move food along tract
Absorb nutrients from food
Egest waste products

Question 2

Sphincters of the gut (6)

Answer 2

Upper oesophageal
Lower oesophageal
Pyloric 
Illeocaecal 
Internal/External anal

Question 3

Which is longer the jejunum or the ileum?

Answer 3

Ileum (350cm) Jejunum (250cm)

Question 4

Areas of mechanical disruption (2)

Answer 4

Mouth (teeth)

Stomach (antrum)

Question 5

Sections of the stomach (5)

Answer 5

Cardia
Fundus
Body
Pyloric Antrum
Pylorus

Question 6

Muscle layers of the stomach, from outside to inside (3)

Answer 6

Longitudinal
Circular
Oblique

Question 7

How does the stomach allow for the storage of food (2)

Answer 7

Rugae of the stomach allow for its expansion

Receptive relaxation means intraluminal pressure does not increase when food is received

Question 8

Areas of temporary food storage (2)

Answer 8

Stomach

Colon

Question 9

GI Defences against pathogens (4)

Answer 9

Saliva
HCl
Kupffer cells (liver)
Peyer’s patches (terminal ileum)

Question 10

What are Peyer’s patches?

Answer 10

Lympathtic tissue nodules that are not surrounded in a fibrous capsule. Recognise pathogenic antigens, which are presented to T and B Lymphocytes, resulting n the production of cytotoxic T cells

Question 11

Types of movement (4)

Answer 11

Peristalsis
Segmentation
Haustral shuttling
Mass movements

Question 12

What is the mixture of muscle in the GI tract? (2)

Answer 12

Some skeletal

Mostly smooth muscle

Question 13

Structural features that aid absorption (3)

Answer 13

Length
Folds(plica circularis in the small bowel, haustra in the colon)
Villi/microvilli

Question 14

Mass movement (4)

Answer 14

Colon temporary storage sight
Rectum normally empty
Internal/external anal sphincter
Gastrocolic reflex

Question 15

Mouth fuction (3)

Answer 15

Mechanical disruption of food
Initial digestive enzymes released
Infection control (lysozymes, IgA, IgG)

Question 16

Oesophagus function (3)

Answer 16

Fast transport of bolus to stomach
UOS prevents air entering GI tract
LOS prevents acid reflux

Question 17

Stomach function (6)

Answer 17

Storage
Physical breakdown
Chemical breakdown
Digestion starts
Infection (HCl)
Secreteintrinsic factor (Vit B12)

Question 18

Duodenum function

Answer 18

Site of neutralisation of chyme (HCO3-)

Digestion (pancreatic enzymes and bile, sphincter of Oddi)

Question 19

Jejunum/Ileum function (5)

Answer 19

Final digestion
Nutrient absorption (mainly jejunum)
Water/electrolyte absorption ( mainly ileum)
Bile recirculation (ileum)
B12 absorption (terminal ileum)

Question 20

Colon function (3)

Answer 20

Final water absorption
Final electrolyte absorption
Storage

Question 21

Rectum function (1)

Answer 21

Defaecation

Question 22

Kupffer cells

Answer 22

Specialised macrophages lining the walls of the sinusoids in the liver

Question 23

Peristalsis

Answer 23

Adjacent segments of the alimentary tract alternately contract and relax, which moves food along the tract distally

Question 24

Segementation

Answer 24

Nonadjacent segments of the alimentary tract contract and relax, moving food forwards and then backwards, mixing the food and slowly propelling it distally

Question 25

Gastroclic reflux

Answer 25

Increased motility of the colon in response to stretching of the stomach