The GI Tract

Question 1

what makes up the GI tract

Answer 1

oral cavity
pharynx
oesophagus
stomach
SI
LI
rectum and anus

Question 2

what are the accessory oragsn to the GI travt

Answer 2

teeth
tongue
salivary glands
pancreas
liver
biliary tree and gall bladder

Question 3

what is the embryology of the GI tract?

Answer 3

derived from the primative gut - (contributed to by endoermal and mesodermal primary germ layers)

Question 4

where is the epithelial lining derived from?

Answer 4

the embryonic endoderm (gives rise to specific secretory cells)

Question 5

what does the splanchnic mesoderm give rise to?

Answer 5

connective tissue
smooth muscle
peritoneal covering

Question 6

what are the 3 divisions/segments of the GI tract

Answer 6

Foregut - mouth to duodenum entrance

Midgut - duodenum entrance to over halfway down transverse colon

Hindgut - past halfway down transverse colon to anus

Question 7

what is the vasculature of the 3 sections of the gut

Answer 7

Foregut - coeliac trunk

Midgut - Superior mesenteric artery

Hindgut - Inferior mesenteric artery

Question 8

how does venous drainage in the GI tract happen

Answer 8

hepatic veins drain all major parts of abdominal GIT

superior and inferior mesenteric veins drain the rest

all to inferior vena cava

Question 9

What makes up the foregut

Answer 9

pharynx
larynx
oesophagus
stomach
duodenum (proximal half)
liver
biliary tree & gallbladder
pnacreas

Question 10

What makes up the midgut

Answer 10

duodenum (distal half)
jejunium (middle part of SI)
ileum
cecum
ascending & transverse colon

Question 11

What makes up the hindgut

Answer 11

transverse & descending colon
sigmoid colon
rectum
anal canal

Question 12

what is the normal physiological umbilical hernia?

Answer 12

intestinal loops protruding through the umbilical region of the developing foetus

intestinal loops will return to the abdomen following a number of rotations & fixations of the gut tube

Question 13

what is aomphalocele

Answer 13

the failure of intestinal loops to return back into the abdominal cavity after the physiological herniation

Question 14

what is diverticular disease

Answer 14

the condition of having diverticula of the colon (small pocketing pouches from the wall of the colon)

Question 15

what is Meckel’s ileal diverticulum

Answer 15

embryological remnant of the vitelline duct of the yolk sac attached to the ileocecal

Question 16

what is the peritoneum?

Answer 16

a smooth thin serous membrane lining the abdominal cavity & some of the viscera

Question 17

what are the two layers of the peritoneum

Answer 17

parietal and visceral

Question 18

what are the 4 parts of the stomach

Answer 18

fundus, body, pyloric antrum, pyloric canal

Question 19

where does the stomach receive its blood supply from

Answer 19

common hepatic artery (gastroduodenal artery, splenic branches)

drained by portal vein

Question 20

what separates the left and right lobes of the liver

Answer 20

the falciform ligament

Question 21

what separates the quadrate and caudate lobes of the liver

Answer 21

sagittal fissures and the transverse porta hepatis

Question 22

how is the liver divided and into how many parts

Answer 22

8 parts by the distributions of portal triad and hepatic vein

Question 23

what is the livers dual oxygenated blood supply

Answer 23

hepatic portal vein supply 75-80% (40% more oxygen than other systemic veins)

hepatic artery supply other 20-25%

Question 24

what does the liver have to do with lymph

Answer 24

major producing organ

25-50% of lymph in thoracic duct comes from liver

Question 25

what are the 4 parts of the pancreas

Answer 25

head, neck, body, tail

Question 26

what are the 2 ducts within the pancreas and what do they do

Answer 26

main pancreatic duct (unites with bile duct forming hepatopancreatic ampulla of vater (opens to duodenum)) accessory pancreatic duct

Question 27

where do the duodenum and pancreas get their blood

Answer 27

from branches of splenic, gastroduodenal, superior mesenteric arteries drainage to hepatic portal vein

Question 28

where does the pancreas get its nerve supply

Answer 28

from vagus and abdominopelvic splanchnic nerves

Question 29

what do pancreatic centroacinar cells do

Answer 29

perform exocrine functions, synthesize and secrete the digestive enzymes

Question 30

what do pancreatic stellate cells do

Answer 30

perform functions relating to tissue repair and destruction of tumour cells

Question 31

what are the 4 types of pancreatic islet of Langerhans cells

Answer 31

alpha, beta, delta, F-cells

Question 32

how is the pancreas formed

Answer 32

two buds the endodermal lining of duodenum (dorsal & ventral pancreatic bud) the fuse

Question 33

when does insulin secretion begin

Answer 33

around the 5 month of foetal life

Question 34

what is annular pancreas

Answer 34

improper rotation and migration of the tissue buds - may constrict/obstruct duodenum

Question 35

what would blockage of the hepatopancreatic ampulla cause (gallstones)

Answer 35

pancreatitis to bile reflux

Question 36

what is an endoscopic retrograde cholangiopancreatography

Answer 36

fibre optic endoscope passed through mouth to duodenum injecting radiographic contract to produce an image to diagnosis disease

Question 37

what are the 2 types of pancreatic cancer

Answer 37

exocrine (95%) in head of pancreas endocrine

Question 38

what does cancer in the pancreatic head do?

Answer 38

compresses and obstructs the bile duct, enlarges gallbladder leads to obstructive jaundice

Question 39

what is an pancreatectomy

Answer 39

removal of most or all of the pancreatic cancer

Question 40

what is Whipples procedure

Answer 40

cancer removal from pancreatic head

Question 41

what makes the biliary tree

Answer 41

right and left hepatic ducts (forms hepatic duct) + cystic duct = bile duct + main pancreatic duct = hepatopancreatic ampulla

Question 42

what makes up the small intestine

Answer 42

duodenum (first part, 25cm long takes C shape around pancreas) Jejunum (proximal 2/5) Ileum (distal 3/5)

Question 43

what is the difference between mesenteric and -anti-mesenteric borders

Answer 43

both concave margin of small bowel loop, mesenteric facing towards axis of root of mesentery, other facing away

Question 44

what is the most common position of the appendix

Answer 44

retro-colic or retro caecal (60-75%)

Question 45

what is the rectal canal developed from?

Answer 45

endodermal cloaca of hindgut (upper 2/3s) ectodermal cloaca (lower 1/3) the sections different in blood, nerve and lymphatic supply