Small and large intestines

Question 1

foregut

Answer 1

oropharynx to D2
coeliac trunk

Question 2

mid gut

Answer 2

D2 to distal 1/3 transverse colon
SMA

Question 3

hindgut

Answer 3

distal 1/3 transverse to anus
IMA

Question 4

structure of bowel

Answer 4

interior outwards
- mucosa
-muscularis mucosa
- submucosa
- muscle
- serosa

Question 5

duodenum

Answer 5

c shaped around ehad of pancreas
4 parts

superior D1 - pylorus to right side of L1
intraperitoneal
posterior relations: CBD, PV, gastroduodenal

Descedning D2 - runs inferiorly L1-L2
CBD and pancreatic ducts enter

Inferior
longest
passes infront of IVC and aorta to the left side of L3

Asending
upwards to L2
termiates at DJ flexure - supported by ligamen f triietz (peritoneal fold)

Question 6

blood supply of duodenum

Answer 6

coeliac and sma

coeliac - superior anterior and inferior pancreaticoduodenal areries

sma - inferior anterior and inferior pancreaticoduodenal arteries

Question 7

posterior duodenal ulcer

Answer 7

can be compliacted by erosion of the gastroduodenal artery causing haemorrhage

Question 8

plicae circulares

Answer 8

mucosal folds in the jejunum and ileum

Question 9

blood supply of jejunum an ileum

Answer 9

sma

hehunal and ileal arteries - form arterial arcades which form the straight vasarecta that pass into the intestine

Question 10

differences between ileum and jejunum

Answer 10

ileum is longer (3/5)
jejunum has a thicker wall and large diameter
jejunum is dark red and ileum id pale pink
jejunum has less prominent arterial arcades and longer vasa recta
ileum has a thicker mesentry and peyer’s patches

Question 11

features of large bowel

Answer 11

larger diameter

appendices epiploicae

taenia coli (three bands of longitudinal muscle)

haustra (sacculation caused by contraction of taenia)

Question 12

meckel’s

Answer 12

congenital remnant of vitelline duct occuring in 2% of population

Question 13

caecum

Answer 13

intraperitoneal

continuation of ileum

normally in RIF

enters at an oblique angle so has 2 ileal folds that act as a sphincter

Question 14

blood supply caecum

Answer 14

anterior and posterior caecal arteries from ileocolic branch of SMA

Question 15

where is bowel perf most likely to occur and why

Answer 15

caecum, largest diameter (7-9cm)

Question 16

most likely site of obstruction and why

Answer 16

sigmoid, narrowest

Question 17

position of appendix

Answer 17

posterior medial wall of caecum

suspended from terminal ileum by mesoappendix which contains the appendicular vessels

position is highly variable
- most commonly retrocaecal
can be pelvic, subcaecal or preileal

position of the base is consistent on the caecum where the three bands of taenia converge

Question 18

blood supply appendix

Answer 18

appendicular artery from ileocolic branches of sma

Question 19

colon intra vs retroperitoneal

Answer 19

ascending and descending colons are retroperitoneal

transverse and sigmoid are intraperionteal becayse thay have mesentry

Question 20

symptoms of LBO

Answer 20

absolute constipation
vomiting
distention
colicky pain

Question 21

common causes of LBO

Answer 21

tunour
hernia
diverticular disease

Question 22

branches of SMA supplying colon

Answer 22

colic branch of ileocolic
right colic
middle colic

Question 23

ima branches colon

Answer 23

left colic
sigmoid arteries

Question 24

marginal artery of drummond

Answer 24

connects SMA and IMA

Question 25

watershed area colon

Answer 25

splenic felxure

Question 26

taenia coli in rectum

Answer 26

form a continuous layer of smooth muscle over the rectum

Question 27

peritoneal coverings of rectum

Answer 27

upper 1/3 - extraperitoneal posteriorly middle third - extraperitoneal posterior and lateral lower 1/3 - completely extraperioneal

Question 28

relations to rectum

Answer 28

posterior - sacrum, coccyx, sacral nerves anterior - pouch of douglas, small intestine, bladder, prostate, vagina, uterus lateral - levator ani

Question 29

pouch of douglas

Answer 29

space between rectum and bladder or uterus

Question 30

blood supply rectum

Answer 30

superior rectal from ima internal ilac middle rectal inferior rectal

Question 31

Anal canal

Answer 31

boundary between endoderm and ectoderm upper 1/2 - columnar epithelium - superior rectal vessels - drains to lumbar nodes lower 1/2 - squamous epithelium - middle and inferior rectal vessels - drains to inguinal nodes

Question 32

lymph drainage

Answer 32

along mesentr to nodes near the origin of coeliac, sma and ima. then superiorly throigh cisterna chyli

Question 33

relation of duodeunum to periotneum

Answer 33

1st intraperitoneal 2-4 retroperitoneal

Question 34

blood supply to duodenum

Answer 34

superior pancreaticoduodenal (from gastroduodenal) infereior pancreaticoduodenal (SMA) Breacnhes of hepatic, right gastric, right gstroepiploic, supraduodenal

Question 35

relations to first part duodenum

Answer 35

superior: epiploic foramen inferior: head and neck of pancreas anterior: quadrate lobe of liver, gallbladder posterior: portal vein, gastroduodenal artery, CBD

Question 36

relations second part duodenum

Answer 36

anterior: gallbradder, right lobe liver, trnasverse colon, transverse mesocolon, small intestine posterior: right kidey, renal vessels, IVC, psoas medial: head of pancreas lateral: ascending colon, heaptic flexure, right lobe liver

Question 37

relations 3rd part duodenum

Answer 37

anterior: root of mesentry, SMV/A, jejunum posterior: psoas, ureter, IVC, AA, gonadal vessels superior: head of pancreas and ucinate process inferior: jejunun

Question 38

4th part of duodenum relations

Answer 38

anterior: transverse colon and mesocolon posterior: left psoas, sympathetic chain, left gonadal vessels, IMV superior: body of pancreas left: kidney and ureter right: root mesentry

Question 39

vessels infront and behind 3rd part duodenum

Answer 39

superior mesenteric anterior IVC, right renal and gonadal vessels posteriorly

Question 40

Where is the major duodenal papilla?

Answer 40

papilla of vater posyeromedial wall 2nd part duodenum 10cm distal to pylorus junction of pancreatic duct and CBD (ampulla of vater) in the duodenum

Question 41

possible positions of the appendix

Answer 41

retrocaecal subcaecal pelvic pre-ileal post-ileal

Question 42

blood supply to the appendix

Answer 42

appendicular artery from ileocolic appendicular vein to SMV

Question 43

why is appencitis pain referred to the umbilicus

Answer 43

pain initially starts in the periumbilical region as visceral pain from the appendix - nerve fibres from T10 level when the parietal peritoneum is irritated by the appendix the pain localises to thr RIF

Question 44

douglas pouch

Answer 44

rectouterine pouch