[BS]
Gastrointestinal
ANTERIOR ABDOMINAL WALL & INGUINAL REGION
EO originates from the lower 8 ribs superiorly and runs inferiorly to form the inguinal ligament and attaches to the iliac
crest. Also forms an inferior border, where there is a free edge = inguinal ligament.
Inguinal ligament runs from ASIS pubic tubercle.
Medially, the muscle fibres form an aponeurosis – a flat, fibrous membrane that runs towards midline tough linea alba.
IO comes from costal margin superiorly, thoraco-lumbar fascia posteriorly, iliac crest and lateral 2/3 of inguinal ligament.
TA comes from costal margin superiorly, thoraco-lumbar fascia posteriorly, iliac crest and lateral 1/3 of inguinal ligament.
RA runs downwards from xiphisternum pubic tubercle and pubic crest on the pubic bone.
Contains tough tendinous insertions – linea semilunaris where aponeuroses blend in with RA muscle fibres.
T7-T12 nerves that supply these muscles.
Ilioinguinal and iliohypogastric nerves run behind the kidneys.
Pubic tubercle just lateral to the pubic crest.
Just lateral to pubic tubercle = superficial inguinal ring.
Spermatic cord = vas deferens, ductus deferens, testicular artery and vein, various nerves.
Inguinal canal ~ 4cm long running from superficial inguinal ring deep inguinal ring.
As IO fibres are arching over the spermatic cord, they run to the pubic tubercle.
Conjoint tendon = IO + TA which attaches to the pubic tubercle. Reinforces the posterior wall of the inguinal canal at
approximately the same position as the superficial inguinal ring.
ABDOMINAL CAVITY & PERITONEAL REFLECTIONS
Greater omentum develops from dorsal mesentery. Originates from greater curvature of the stomach. Attached to its
posterior surface is the transverse colon, with many fatty tags (characteristic).
Transverse mesocolon runs from transverse colon to PAW. Forms mesocolic shelf.
Falciform ligament is a remnant of the ventral mesentery. Liver develops within ventral mesentery. Running within the free
edge of the falciform ligament is ligamentum Teres – remnant of umbilical vein.
Falciform ligament separates supracolic compartment into R & L parts.
Coronary ligament extends from liver to diaphragm; is a peritoneal reflection.
Hepatorenal recess is the lowest, deepest space in a supine patient – site of accumulation of free fluid/pus.
Lesser sac is a peritoneal space that lies posterior to the stomach. Lies behind a remnant of the ventral mesentery that ran
from stomach to liver = lesser omentum.
Lesser omentum has a free anterior border which contains: bile duct, hepatic artery, hepatic portal vein.
, [BS]
Anterior structures of epiploic foramen = those found in free edge of lesser omentum.
Posteriorly = IVC.
Superiorly = liver.
Inferiorly = first part of the duodenum.
Distal end of SI = caecum, which is a dilated sac.
Phrenicocolic ligament runs from splenic flexure to the diaphragm. Prevents spleen from travelling inferiorly down the
abdomen when it enlarges. ∴ means when spleen enlarges, it enlarges anteriorly and diagonally across abdo.
Ascending and descending colon are secondarily retroperitoneal.
Either side of the colon, there are some narrow channels = paracolic gutters. Right lateral and medial paracolic gutters.
Right lateral paracolic gutter is continuous with the hepatorenal recess. This allows a pathway for free fluid/pus to travel
from the infracolic compartment supracolic compartment.
STOMACH, MIDGUT & ASSOCIATED ARTERIES
Gastrocolic ligament extends down from the greater curvature of the stomach to the transverse colon.
Lesser sac (recess of peritoneal cavity which lies behind the stomach) and allows the stomach to ↑ in volume.
POST boundary of lesser sac: pancreas, splenic artery (runs along superior border of pancreas), bulge of L adrenal gland,
kidney.
There’s a v small portion of oesophagus that is abdominal.
Thickening of circular muscle pyloric sphincter.
Coeliac trunk only ~ 1cm long and comes off just below T12 vertebra.
R gastric artery branches off hepatic artery. R gastric gives many small branches.
Appendices epiplicae are covered in peritoneum.
Taenia coli run from appendix to rectum. 3 bands of longitudinal muscle.
Just to R of SMA = SMV.
Arterial arcade = loop connected by 2 jejunal arteries. Parallel to SI.
Middle colic runs in transverse mesocolon.
Marginal artery runs along the transverse and desc. colon. It is started off by middle colic uniting with R colic.
Gastrointestinal
ANTERIOR ABDOMINAL WALL & INGUINAL REGION
EO originates from the lower 8 ribs superiorly and runs inferiorly to form the inguinal ligament and attaches to the iliac
crest. Also forms an inferior border, where there is a free edge = inguinal ligament.
Inguinal ligament runs from ASIS pubic tubercle.
Medially, the muscle fibres form an aponeurosis – a flat, fibrous membrane that runs towards midline tough linea alba.
IO comes from costal margin superiorly, thoraco-lumbar fascia posteriorly, iliac crest and lateral 2/3 of inguinal ligament.
TA comes from costal margin superiorly, thoraco-lumbar fascia posteriorly, iliac crest and lateral 1/3 of inguinal ligament.
RA runs downwards from xiphisternum pubic tubercle and pubic crest on the pubic bone.
Contains tough tendinous insertions – linea semilunaris where aponeuroses blend in with RA muscle fibres.
T7-T12 nerves that supply these muscles.
Ilioinguinal and iliohypogastric nerves run behind the kidneys.
Pubic tubercle just lateral to the pubic crest.
Just lateral to pubic tubercle = superficial inguinal ring.
Spermatic cord = vas deferens, ductus deferens, testicular artery and vein, various nerves.
Inguinal canal ~ 4cm long running from superficial inguinal ring deep inguinal ring.
As IO fibres are arching over the spermatic cord, they run to the pubic tubercle.
Conjoint tendon = IO + TA which attaches to the pubic tubercle. Reinforces the posterior wall of the inguinal canal at
approximately the same position as the superficial inguinal ring.
ABDOMINAL CAVITY & PERITONEAL REFLECTIONS
Greater omentum develops from dorsal mesentery. Originates from greater curvature of the stomach. Attached to its
posterior surface is the transverse colon, with many fatty tags (characteristic).
Transverse mesocolon runs from transverse colon to PAW. Forms mesocolic shelf.
Falciform ligament is a remnant of the ventral mesentery. Liver develops within ventral mesentery. Running within the free
edge of the falciform ligament is ligamentum Teres – remnant of umbilical vein.
Falciform ligament separates supracolic compartment into R & L parts.
Coronary ligament extends from liver to diaphragm; is a peritoneal reflection.
Hepatorenal recess is the lowest, deepest space in a supine patient – site of accumulation of free fluid/pus.
Lesser sac is a peritoneal space that lies posterior to the stomach. Lies behind a remnant of the ventral mesentery that ran
from stomach to liver = lesser omentum.
Lesser omentum has a free anterior border which contains: bile duct, hepatic artery, hepatic portal vein.
, [BS]
Anterior structures of epiploic foramen = those found in free edge of lesser omentum.
Posteriorly = IVC.
Superiorly = liver.
Inferiorly = first part of the duodenum.
Distal end of SI = caecum, which is a dilated sac.
Phrenicocolic ligament runs from splenic flexure to the diaphragm. Prevents spleen from travelling inferiorly down the
abdomen when it enlarges. ∴ means when spleen enlarges, it enlarges anteriorly and diagonally across abdo.
Ascending and descending colon are secondarily retroperitoneal.
Either side of the colon, there are some narrow channels = paracolic gutters. Right lateral and medial paracolic gutters.
Right lateral paracolic gutter is continuous with the hepatorenal recess. This allows a pathway for free fluid/pus to travel
from the infracolic compartment supracolic compartment.
STOMACH, MIDGUT & ASSOCIATED ARTERIES
Gastrocolic ligament extends down from the greater curvature of the stomach to the transverse colon.
Lesser sac (recess of peritoneal cavity which lies behind the stomach) and allows the stomach to ↑ in volume.
POST boundary of lesser sac: pancreas, splenic artery (runs along superior border of pancreas), bulge of L adrenal gland,
kidney.
There’s a v small portion of oesophagus that is abdominal.
Thickening of circular muscle pyloric sphincter.
Coeliac trunk only ~ 1cm long and comes off just below T12 vertebra.
R gastric artery branches off hepatic artery. R gastric gives many small branches.
Appendices epiplicae are covered in peritoneum.
Taenia coli run from appendix to rectum. 3 bands of longitudinal muscle.
Just to R of SMA = SMV.
Arterial arcade = loop connected by 2 jejunal arteries. Parallel to SI.
Middle colic runs in transverse mesocolon.
Marginal artery runs along the transverse and desc. colon. It is started off by middle colic uniting with R colic.
