anatomy of the GI tract Flashcards
what is the anterior, lateral, and posterior walls of the abdomen are composed of?
skin, subcutaneous tissue and muscles and their associated aponeuroses (flat tendons)
what are the functions of the abdominal wall?
- protect the abdominal viscera
- increase intra-abdominal pressure (e.g. for defecation and childbirth)
- maintain posture and move the trunk
what is the name of the serous membrane that lines the internal abdominal wall?
parietal peritoneum
how is the abdominal region be split into 9 parts?
four imaginary lines:
* the right and left midclavicular lines
* the subcostal line: underneath the most inferior part of the costal margin
* the intertubercular line: a horizontal line drawn through the tubercles of the right and left iliac crests
what are the names of the 9 regions in which the abdomen can be split into?
superior right to left: right hypochondrium
middle right to left: right flank, umbilical region, left flank
inferior right to left: right iliac fossa, suprapubic region, left iliac fossa
where is the transpyloric plane?
lies halfway between the superior border of the manubrium and the pubic symphysis; a horizontal line that passes through the tips of the right and left ninth costal cartilage
what does the transpyloric plane transect?
the pylorus of the stomach, the gallbladder, the pancreas and the hila of the kidneys
where is the transumbilical plane?
going across the belly button (umbilicus)
where is the intercristal plane?
a horizontal line drawn between the highest points of the right and left iliac crests used to guide procedures on the back (e.g. lumbar puncture)
where is McBurney’s point?
lies two thirds of the way along a line drawn from the umbilicus to the right anterior superior iliac spine, and is the surface marking of the base of the appendix
what are the four pairs of muscles in the anterolateral abdominal wall?
- external oblique (diagonally orientated fibres)
- internal oblique (diagonally orientated fibres)
- transversus abdominis (horizontally orientated fibres)
- rectus abdominis (rectus = straight).
how do the fibres of the external obliques lie?
run medially and inferiorly, towards the midline
how do the fibres of the internal obliques lie?
are orientated perpendicular to those of EO (they run medially and superiorly)
where does the transversus abdominis lie and how are the fibres orientated??
deep to the internal oblique, horizontally
what happens when the muscles of the abdomen contact?
increase intra-abdominal pressure
what are the lateral flexors of the lumbar spine?
oblique muscles
what do the muscles of the abdomen become anteriorly?
a flat tendon aponeurotic forming a ‘white line’ called linea alba
what is the rectus sheath and what is it formed from?
encloses the rectus abdominis, formed from the aponeuroses of abdominal muscles
what forms the anterior wall of the rectus sheath?
the anterior layer of the internal oblique aponeurosis and the externa oblique
what forms the posterior wall of the rectus sheath?
posterior layer of the IO aponeurosis and the transversus abdominis aponeurosis
what lies deep to the transverse abdominis?
transversalis fascia
what lies deep to the transversalis fascia?
parietal peritoneum
what arteries supply the anterolateral abdominal wall>
- musculophrenic artery, a branch of the internal thoracic
- superior epigastric artery, which is the continuation of the internal thoracic artery. It descends in the rectus sheath
- inferior epigastric artery, a branch of the external iliac artery. It ascends in the rectus sheath and anastomoses with the superior epigastric.
what is the innervation of the anterior abdominal wall?
● thoraco-abdominal nerves T7 – T11. These are essentially the continuation of the intercostal nerves T7 – T11. These somatic nerves contain sensory and motor fibres.
● the subcostal nerve – this originates from the T12 spinal nerve (so called because it runs along the inferior border of the 12th rib).
● iliohypogastric and ilioinguinal nerves – both are branches of the L1 spinal nerve.
what is the inguinal canal?
an oblique passageway through the muscles of the anterior abdominal wall and lies superior to the medial half of the inguinal ligament. it passes through each layer of the abdominal wall as it travels medially and inferiorly
what is found in the anterior border of the inguinal canal?
● external oblique aponeurosis
● laterally only: internal oblique aponeurosis
what is found in the posterior border of the inguinal canal?
● transversalis fascia
● medially only: medial fibres of the aponeuroses of the internal oblique and transversus abdominis (which are together known as the conjoint tendon).
what is found in the roof of the inguinal canal?
● transversalis fascia
● arching fibres of the internal oblique and transversus abdominis.
what is found in the floor of the inguinal canal?
● inguinal ligament (the lower border of the external oblique aponeurosis).
what is a hernia?
an abnormal protrusion of tissues or organs from one region into another through an opening or defect
what is the peritoneum?
is a serous membrane that lines the abdominal wall and covers the viscera within it
where is the parietal peritoneum?
lines the abdominal wall, can be seen with a naked eye
what does pain to the parietal peritoneum feel like?
sharp, severe, and well localised to the abdominal wall
where is visceral peritoneum found?
covers the abdominal viscera, cannot be seen with a naked eye
what does pain from the visceral peritoneum feel like?
usually dull and diffuse (i.e. it cannot be pinpointed to a specific location), severe
where is the peritoneal cavity, what lies within it and what is its purpose?
between the parietal and visceral peritoneum
a thin film of peritoneal fluid lies in the peritoneal cavity
It allows the viscera to slide freely alongside each other
what does it mean when an abdominal viscera is described as intraperitoneal?
almost completely covered by peritoneum e.g. the stomach
what does it mean when an abdominal viscera is described as retro peritoneal?
posterior to the peritoneum, hence only covered by peritoneum on their anterior surface e.g. the pancreas and abdominal aorta
what are mesenteries?
folds of peritoneum that contain fat and suspend the small intestine and parts of the large intestine from the posterior abdominal wall
what is contained within the mesenteries?
arteries that supply the intestine (from the abdominal aorta) and veins that drain the gut (tributaries of the portal venous system
what are the folds of the peritoneum called?
greater and lesser omenta
where is the greater omentum?
hangs from the greater curvature of the stomach and lies superficial to the small intestine
where is the lesser omentum?
connects the stomach and duodenum (the first part of the small intestine) to the liver
what is contained within the lesser omentum?
hepatic artery, the hepatic portal vein, and the bile duct (the ‘portal triad’) are embedded within its free edge
what are ligaments within the peritoneum?
folds of peritoneum that connect organs to each other or to the abdominal wall
what are some examples of ligaments within the peritoneum and what do they connect?
- falciform ligament, which connects the anterior surface of the liver to the anterior abdominal wall
- the coronary and triangular ligaments, which connect the superior surface of the liver to the diaphragm.
what are peritoneal folds?
raised from the internal aspect of the lower abdominal wall and are created by the structures they overlie, like carpet running over a cable
what is the peritoneal cavity divided into?
the greater and lesser sacs
where is the smaller lesser sac of the peritoneal cavity?
a space that lies posterior to the stomach and anterior to the pancreas
how do the lesser and greater sacs of the peritoneal cavity communicate?
via a passageway that lies posterior to the free edge of the lesser omentum, the epiploic foramen (also called the omental foramen).
where does the gastrointestinal system develop within an embryo?
embryonic gut tube
what is peritonitis?
infection and inflammation of the peritoneum
what are peritoneal adhesions?
pathological fibrous connections between the parietal and visceral peritoneum. when the peritoneum is irritated (e.g. by infection) it produces fibrin which causes the parietal and visceral peritoneum to adhere to each other. these connections may become fibrous.
what are the symptoms of peritoneal adhesions?
chronic abdominal pain and they increase the risk of volvulus (twisting) of the intestine, because it can no longer move freely
what is ascites
an increased volume of peritoneal fluid
where does the foregut extend to?
oesophagus to halfway along the duodenum
where does the midgut extend to?
2/3 transverse colon
where does the hindgut extend to?
upper anal canal
what happens to the abdominal aorta at L4/L5?
bifurcates to the left and right iliac arteries
where does the celiac trunk form from and what do they supply?
T12, supplies the foregut
where does the superior mesenteric form from and what do they supply?
L1, supplies midgut
where does the inferior mesenteric form from and what do they supply?
L3 supplies hindgut
what branches from the coeliac trunk and what do they supply?
- left gastric
- sphlenic artery
- common hepatic artery
what is the name of the area where the oesophagus passes through the diaphragm called?
oesophageal hiatus, at around T10
how is food in the stomach prevented from re-entering the oesophagus?
the muscle around the oesophageal hiatus acts as a sphincter
what supplies the distil oesophagus with blood?
branches from the left gastric artery
what drains the distil oesophagus of blood?
towards the azygos
vein via the oesophageal
veins and to the portal venous system (via the gastric veins)
what is the most superior part of the stomach called?
the fundus
what is the largest part of the stomach called?
the body
what is distil to the body of the stomach?
the pyloric part
what is the pyloric part broken up into?
the body leads to the pyloric antrum, which leads to pyloric canal that contains the pyloric sphincter
what are the borders of the stomach called?
the right border is called the lesser curvature whereas the left border is called the greater curvature
which quadrant does the stomach lie in?
upper left quadrant
what covers the stomach
visceral peritoneum
where is the lesser omentum found?
in between the liver and the stomach
where is the grater omentum found?
hangs from the greater curvature of the stomach
what supplies blood to the stomach?
arteries that branch from the coeliac trunk
what is the foregut composed of?
the stomach, first half of the duodenum, the liver, gallbladder and pancreas
what does the coeliac trunk divide into?
left gastric artery, the common hepatic artery, and the splenic artery
where does the right gastric artery arise from?
either the common hepatic artery or the hepatic artery proper
what do the right and left gastric arteries do?
run along the lesser curvature of the stomach and anastomose with each other
what arteries run along the greater curvature of the stomach and what do they do?
run along the greater curvature of the stomach and anastomose with each other
where does the left gastro-omental artery arise from?
splenic artery
where does the right gastro-omental artery arise from?
gastroduodenal artery, a branch of the common hepatic artery
where do the veins of the stomach empty into?
hepatic portal vein
what is the hepatic portal
vein?
a large vein that carries nutrient-rich venous blood from the GI tract to the liver
what provides parasympathetic innervation to the stomach?
the vagus nerve
what are examples of parasympathetic stimulation in the stomach?
peristalsis and gastric secretion
what provides sympathetic innervation to the stomach?
the greater splanchnic nerve
what is hiatus hernia?
abdominal oesophagus and upper part of the stomach may herniate through the oesophageal hiatus into the thorax
what are the symptoms of hiatus hernia?
if contents of the stomach reflux into the oesophagus the patient may experience heartburn (a burning feeling in the chest after eating) and acid reflux (regurgitation of bitter fluid)
what is a gastric ulcer?
a gastric (stomach) ulcer develops when the mucosal lining of the stomach breaks down
what does the mucosal lining do?
lines the internal wall of the stomach and protects the mucosa from the acidic stomach contents
what does helicobacter pylori do?
erodes the mucosal lining, exposing the muscular wall to gastric acid and enzymes
what is pyloric stenosis?
a congenital malformation characterised by hypertrophy of the circular smooth muscle of the pyloric sphincter
what are the symptoms of pyloric stenosis?
of vomiting (sometimes projectile) after feeds, but the baby does not appear unwell and is hungry and willing to take more feeds
what is gastric cancer?
primary cancer of the stomach
what are symptoms of gastric cancer?
abdominal discomfort, early satiety (feeling full quickly), loss of appetite, nausea, weight loss, difficulty swallowing and indigestion
what are the three parts of the small intestine?
duodenum, the jejunum, and the ileum
where is the duodenum, is it intraperitoneal or retroperitoneal?
continuous with the pylorus of the stomach, retroperitoneal
what is the major duodenal papilla and where is it found?
the opening of the bile duct and the main pancreatic duct into the duodenum, found halfway along the internal wall of the duodenum
where does the first half of the duodenum develop from?
embryological foregut
what supplies the first half of the duodenum?
arterial branches from the coeliac trunk
where does the second half of the duodenum develop from?
embryological midgut
what supplies the second half of the duodenum?
superior mesenteric artery
where is the jejunum?
continuous with the duodenum, in the left upper region
is the jejunum retroperitoneal or intraperitoneal?
intraperitoneal
how are the jejunum and ileum held to the posterior abdominal wall?
the mesentery of the small intestine
what supplies the small intestine and where do they come from and where are they held?
intestine (from the superior mesenteric artery) are embedded within the mesentery
where is the ileum?
in the right lower region
where were the jejunum and ileum are derived from embryologically?
midgut
what happens at the jejunum and the ileum, and how are they adapted for there function?
nutrient absorption, so have a vast surface area: the small intestine is long, the mucosa is folded (plicae circulares), the mucosal folds bear villi and there are microvilli on the luminal surface of each epithelial cell
how can the ileum be differentiated from the jejunum?
plicae are more pronounced in the jejunum and the internal ileum is characterised by Peyer’s patches, which are large submucosal lymph nodules
what is Meckel’s diverticulum?
a blind-ended diverticulum approximately one metre from its termination in the ileum
what is the terminal ileum continuous with?
the caecum - the first part of the large intestine – at the ileocaecal junction in the right iliac fossa
what is the purpose of the large intestine?
intestine reabsorbs water from faecal material to form semi-solid faeces
what is the large intestine composed of?
the caecum, appendix, ascending colon, transverse colon, descending colon, sigmoid colon, rectum, and anal canal
where at what is the appendix?
a small diverticulum that arises from the caecum and contains lymphoid tissue. the surface marking of the base of the appendix is McBurney’s point
is the ascending colon reteroperitoneal?
yes
is the transverse colon reteroperitoneal?
no
what is the bend in the transverse colon called?
splenic flexure
what is the bend in the ascending colon called?
hepatic flexure
where did the transverse colon develop embryologically?
proximal (first) two thirds develop from the embryological midgut, whilst the distal (last) third develops from the embryological hindgut
is the descending colon reteroperitoneal?
yes
what is the area where the colon runs in called?
paracolic gutter
where is the sigmoid colon?
continuous with the descending colon superiorly and the rectum inferiorly, in the lower left quadrant
is the sigmoid colon retroperitoneal and what is it called?
no, sigmoid mesocolon
where is the rectum and is it retriperitoneal?
in the pelvis and is retroperitoneal
what is the rectrosigmoidal junction?
the sigmoid approaches the midline, it makes a 90 degree turn inferiorly into the pelvis
where does the superior mesenteric leave the aorta?
L1
what does the superior mesenteric supply?
the midgut structures: the second half of the duodenum, the small intestine, and the large intestine as far as (and including) the first two thirds of the transverse colon. branches also supply parts of the pancreas
what are some major branches of the SMA?
- jejunal branches – several branches to the jejunum
- ileal branches – several branches to the ileum
- ileocolic artery – supplies the caecum, appendix, and ascending colon
- right colic artery – supplies the ascending colon
- middle colic artery – supplies the transverse colon
where does the IMA leave the aorta?
L34
what does the IMA supply?
the distal third of the transverse colon, the descending and sigmoid colon, the rectum, and the upper part of the anal canal
what major branches arise from the IMA?
- left colic artery – supplies the transverse colon and the descending colon
- sigmoid branches – supply the sigmoid colon
- superior rectal artery – the terminal branch of the IMA, which supplies the rectum.
aside from the IMA, what else supplies the rectum?
middle and inferior rectal arteries which branch from the internal iliac arteries in the pelvis
what drains the hindgut?
inferior mesenteric vein (IMV), which drains into the splenic vein from the spleen where it goes into the portal and systemic system
why does venous blood enter the liver via the portal
venous system before being returned to the heart
via the IVC?
because it still contains absorbed nutrients
what drains the midgut?
superior mesenteric vein ; it ascends and unites with the splenic vein close to the liver (posterior to the neck of the pancreas) to form the hepatic portal vein
what innervates the foregut and midgut parasympathetically?
vagus nerve
what innervates the hindgut parasympathetically?
pelvic splanchnic nerves
where do the cell bodies of preganglionic parasympathetic neurons lie?
sacral segments S2 – S4
where are the ganglia of the pelvic splanchnic nerves located?
very close to, or even within, the walls of the viscera
what sympathetically innervates the foregut?
greater splanchnic carries fibres from T5 – T9
what sympathetically innervates the midgut?
lesser splanchnic carries fibres from T10 – T11
what sympathetically innervates the hindgut?
least splanchnic carries fibres from T12
what impact do visceral sympathetic and parasympathetic nerves to the stomach have on the body
visceral sensory fibres that travel with sympathetic nerves convey painful sensations, whereas visceral sensory fibres that travel with parasympathetic nerves convey information that maintains the internal environment and elicits reflex responses
what does epigastric pain suggest?
foregut pathology
what does umbilical pain suggest?
midgut pathology
what quadrants is the liver located in?
right upper quadrant and epigastrium
what travels up the hepatic portal vein?
the products of digestion, except lipids
what are the two surfaces of the liver?
- the diaphragmatic surface lies anterosuperior and is related to the inferior surface of the diaphragm.
- the visceral surface lies posteroinferior and is related to other organs.
what regions of the liver are not covered by visceral peritoneum?
- bare area of the liver – a region on the posterior surface that lies in contact with the diaphragm
- the region where the gallbladder lies in contact with the liver
- region of the porta hepatis – where hepatic blood vessels and ducts of the biliary system enter and exit the liver (the equivalent of the hilum of the lung).
what are the two lobes of the liver? what is it separated by?
large right lobe and small left lobe, separated by the falciform ligament
what is the falciform ligament?
fold of the peritoneum that separates joins the anterior surface of the liver with the wall of the abdomen
what are the accessory lobes of the liver and where are they located?
caudate and quadrate lobes, are located on the posteroinferior surface
how is the liver separated internally, and how is each segment differentiated?
eight functional segments. each segment is served by its own branch of the hepatic artery and portal vein, and by its own hepatic duct
how is the liver connected to the diaphragm?
by coronary and triangular ligaments
how is the liver connected to the stomach and duodenum?
the lesser omentum
what is the portal triad?
the hepatic artery, hepatic portal vein and the bile duct run together as the portal triad in the free edge of the lesser omentum
what is the epiploic foramen?
the entrance into the lesser sac
what forms the anterior boundary of the epiploic foramen?
the portal triad and the free edge of the lesser omentum
what recesses are related to the liver and where do they lie?
- the hepatorenal recess lies between the right kidney and the posterior (visceral) surface of the right side of the liver. fluid flows into this space in the supine position.
- the left and right subphrenic recesses lie either side of the falciform ligament, between the anterosuperior surface of the liver and the diaphragm.
what is a recess?
small pockets or fossae in the peritoneal cavity, which are bounded by folds of peritoneum
which part of the embryological gut tube does the liver develop from?
foregut
what is the ventral mesentery?
peritoneal fold in the upper abdomen that connects the stomach to the anterior abdominal wall
how does the liver develop?
grows from the ventral mesentery, and migrates to the right side of the abdomen
what does the ventral mesentery become and how?
falciform ligament and lesser omentum as the migrating liver pulls the peritoneal attachments
what is the round ligament of the liver and where is it found?
the free edge of the falciform ligament contains the round ligament of the liver (the ligamentum teres). it is the remnant of the umbilical vein, which, in the foetus, carries oxygenated blood from the placenta to the foetus
what is the ligamentum venosum of the liver and where is it found?
lies on the posterior surface of the liver, in the groove between the caudate lobe and the left lobe of the liver. It is the remains of the ductus venosus, which in foetal life diverts blood from the umbilical vein to the IVC, thus shunting oxygen-rich blood to the heart and bypassing the liver
what is the arterial supply of the liver?
right and left hepatic arteries
what does the hepatic artery proper bifurcate into and where do they enter the liver?
bifurcates into right and left hepatic arteries, which enter the liver at the porta hepatis
how does venous blood exit the liver? what do these unite with and where?
liver via two or three large hepatic veins that lie within the liver – they are not visible external to the liver. they unite with the inferior vena cava as it passes posterior to the liver
what does the hepatic portal
vein receive blood from?
the superior and inferior mesenteric veins and the splenic vein
what innervates the liver, and how do these nerves travel?
the hepatic plexus, which is formed of parasympathetic fibres from the vagus nerves and sympathetic fibres. these fibres follow the paths of the hepatic vessels and ducts of the biliary tree
what is the main part of the gallbladder called?
the body
what is the fundus of the gallbladder?
the rounded end of the gallbladder which typically extends to the inferior border of the liver
where is the surface marking of the fundus of the gallbladder?
the tip of the 9th costal cartilage at the point where the right midclavicular line intersects the right costal margin
what is bile produced by?
continuously produced by hepatocytes in the liver
what vessels does bile flow down once it has been formed?
first excreted into small channels called bile canaliculi. the canaliculi drain into bile ducts of increasing calibre, which ultimately converge to form right and left hepatic ducts that exit the liver at the porta hepatis
what do the left and right hepatic ducts converge to form?
common hepatic duct
what is the cystic duct?
connects the top of the gallbladder’s neck to the common hepatic duct
where does the common bile duct run?
in the free edge of the lesser omentum
what happens to bile that leaves the liver that is not needed for digestion?
it enters the gallbladder via the cystic duct
how does bile flow from the gallbladder for use?
via the cystic duct, to the common bile duct and duodenum
where is the spiral fold?
lies at the junction between the gallbladder neck and the cystic duct
what is the blood supply of the gallbladder and where does this arise from?
via the cystic artery, which typically arises from the right hepatic artery (variation exists)
what is drains the gallbladder and does this go?
is drained by cystic veins that pass directly into the liver or join the hepatic portal vein
what type of nerves innervate the gallbladder?
parasympathetic and sympathetic fibres
why is visceral pain from the gallbladder felt in the epigastrium?
visceral afferents enters spinal cord levels T5 – T9
why is gall bladder pain sometimes felt in the right shoulder?
if gallbladder pathology irritates the diaphragm, which is innervates by the phrenic nerve C34-C5, pain can be felt in the right shoulder because C34-5 also receive information from the
skin over the shoulder
why may gallbladder pathology lead to pain in the right hypochondrium?
if the pathology affects the parietal pleura, the pain is well localised
what is hepatomegaly? what causes it?
enlargement of the liver, hepatitis, malignancy, heart failure
what is liver metastases?
cancer from other parts of the body reaching the liver, which causes most liver cancers venous blood from the gut passes through the liver, bowel cancers often metastasize to the liver
what is cirrhosis of the liver? what causes it
scarring, chronic excess alcohol consumption, chronic infection with hepatitis B or C, or a build-up of fat in the liver
what are gallstones and where do they cause pain?
mostly composed of cholesterol, cause symptoms when they migrate into the biliary tree and lodge there
what is biliary colic?
gallstone lodges in the cystic duct, contraction of the gallbladder against it causes severe pain
what causes cholecystitis and how is it treated?
when the gallstone gets stuck in the cystic duct is blocks the flow of bile, inflaming the cystic ducts and the gallbladder. treated by laparoscopy (cholecystectomy)
what are the four parts of the duodenum?
superior (first), descending (second), the inferior (third) and the ascending (fourth) parts
where do the common bile duct, gastroduodenal artery and the hepatic portal vein lie compared to the duodenum?
posterior to the first part of the duodenum
where does the superior mesenteric artery lie compared to the duodenum?
anterior to the third part
what is where the duodenum and the jejunum meet called?
duodenojejunal flexure
what supplies the first half of the duodenum?
branches from the coeliac trunk
what supplies the second half of the duodenum?
branches of the superior mesenteric artery
at what level does the pancreas lie?
L1
what is the pancreas formed form?
dorsal and ventral pancreatic buds which fuse during development
what is the pancreas composed of?
four parts: the head, the neck, the body, and the tail
what does the tail of the pancreas extend to?
the hilum of the spleen
how does pancreatic juice reach the duodenum?
transported through main pancreatic duct and the accessory pancreatic duct to the duodenum
where do the main pancreatic duct and the accessory pancreatic duct run?
within the substance of the pancreas
where do the common bile duct and main pancreatic duct merge at?
hepatopancreatic ampulla (ampulla = dilation)
where does the hepatopancreatic ampulla opens into the second part of the duodenum at?
major duodenal papilla
what surrounds the hepatopancreatic ampulla and why?
smooth muscle, hepatopancreatic sphincter which when contracted prevents reflux of duodenal contents into the common bile duct and main pancreatic duct
where does the accessory pancreatic duct empties pancreatic juice into the duodenum? where does this lie?
minor duodenal papilla, which lies just proximal to the major duodenal papilla
what supplies blood to the pancreas?
- the splenic artery, a major branch from the coeliac trunk, runs along the upper border of the pancreas and gives rise to pancreatic arteries.
- the gastroduodenal artery (from the common hepatic artery and hence the coeliac trunk) gives rise to the superior pancreaticoduodenal arteries that supply the pancreas.
- the superior mesenteric artery gives rise to the inferior pancreaticoduodenal arteries that supply the pancreas.
what drains the pancreas?
splenic vein drains the pancreas and unites with the superior mesenteric vein to form the hepatic portal vein posterior to the neck of the pancreas
what is the function of the spleen?
the breakdown of old red blood cells, the storage of red blood cells and platelets, and various immune responses, including production of IgG
what supplies the spleen? how does it travel to the spleen?
the splenic artery, a branch of the coeliac trunk. runs along the superior border of the pancreas, embedded within it. the artery divides into approximately five branches at the hilum
how does blood drain from the spleen? what does it unite with?
is via the splenic vein, which runs posterior to the pancreas. it unites with the superior mesenteric vein to form the hepatic portal vein
