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223 Cards in this Set

  • Front
  • Back
superior margin of the abdominal wall
right and left costal cartilages
lateral margin-upper portion of the abdominal wall
abdominal side wall
lateral margin-lower portion of the abdominal wall
iliac crests
inferior margin
inguinal ligament/symphysis pubis
quadrants of the abdomen
divided by the midline and the umbilicus, right and left, upper and lower
superficial fascia of the abdomen
fatty subQ layer, composed to two different types: Camper’s Fascia (fatty superficial layer) and Scarpa’s Fascia (membranous deeper layer)
Camper’s fascia
fatty superficial layer, inferior to costal margin, superior to the inguinal ligament
Scarpa’s fascia
membranous deep layer, continuous with the fascia lata of the lateral thigh and the superficial perineal fascia around the scrotum and penis (Cole’s fascia)
what are the muscles that make up the abdominal wall?
1. external oblique
2. internal oblique
3. transversus abdominus
4. rectus abdominus
external oblique
origin: external surface of the 5th through 12th ribs
direction: run diagonally from the rib to the pubic tubercle, like hands in a pocket
insertion: linea alba medially, pubic tubercle inferior/medially, and anterior iliac crest inferior laterally
action: flex and rotate trunk, support abdominal viscera
innervation: T7-T11 intercostal nerves, subcostal nerve and iliohypogastric nerve
inguinal ligament
formed from the aponeurosis of the external oblique (the inferior aspect of the external oblique), a line of fascia between the anterior iliac spine and the pubic tubercle
superficial inguinal ring
opening in the external oblique aponeurosis medially, considered an area of weakness, spermatic cord leaves through here covered with external spermatic fascia,
internal oblique
runs inferior to the external oblique
origin: anterior 2/3 of iliac crest and lateral 2/3 of inguinal ligament
direction: runs at right angles to the external oblique
insertion: inferior 3-4 ribs superiorly and linea alba medially
action: flex and rotate trunk (with the external oblique)
innervation: T7-T11 intercostal nerves, iliohypogastric, ilioinguinal and subcostal nerves
internal oblique and the rectus sheath
medially the internal oblique splits to enclose the rectus abdominus sheath, inferiorly the internal oblique aponeurosis forms the conjoint tendon
transversus abdominus
runs posterior to the internal oblique
origin: inferior 6 costal cartilages
direction: run horizontal
insertion: into the linea alba medially and the pubis (as part of the conjoint tendon)
action: supports the abdominal viscera
innervation: T7-T11 intercostal nerves, iliohypogastric, ilioinguinal and subcostal nerves
rectus abdominus
lies medial to the external and internal obliques and the transversus abdominus, called the strap muscle
origin: symphysis pubis and pubic crest
insertion: xiphoid process and 5th-7th costal cartilages
action: flexes trunk and tenses abdominal wall
innervation: T7-T11 intercosal nerves and subcostal nerve
rectus sheath
a covering over each rectus abdominus muscle, anterior leaf formed by the external oblique and part of the internal oblique aponeurosis, posterior leaf formed by the transversus abdominus and part of the internal oblique aponeurosis
arcuate line
half way between the umbilicus and pubic crest, below this line the posterior rectus sheath is absent around the rectus abdominus, the internal oblique and transversus abdominus portions now make up the anterior leaf
structures housed within the rectus sheath
superior epigastric artery-end of internal thoracic artery, branch of the subclavian artery
inferior epigastric artery-branch of external iliac artery
linea alba
midline that separates the two rectus abdominus muscles
linea semilunares
lateral border of rectus muscle
umbilicus
inferior to the midpoint of the linea alba
gastroschisis or omphaloceles
develop when the muscles do not fuse after the bowel extrudes from the abdomen during the 6-8th week of gestation
transversalis fascia
deep to the transversus abdominus, a transparent fasica that lines the entire abdominal wall, changes name depending on the position (diaphragmatic fascia, pelvic fascia, femoral sheath)
peritoneum
deep to the transversalis fascia, may have a layer of fat between the peritoneum and the transversalis fascia (extraperitoneal fat)
innervation of the abdominal skin
T7-T11 and subcostal nerve
innervation of the inferior aspect of the abdominal wall
L1 via the iliohypogastric and iliolingual nerves
innervation of the rectus sheath
all nerves pass between or through muscle to reach the rectus sheath, cutaneous nerves provide sensation
T6-subxiphoid
T10-umbilical area
T12/L1-suprapubic area
surgical incisions
midline incision-goes through the linea alba to minimize the amount of nerves hit
transverse incision-goes through the external and internal obliques, transversus and possibly the rectus, also minimizes the amount of nerves hit but is a weaker incision
blood supply to the anterior abdominal wall
1. T10-T11 intercostal arteries-encircle abdominal cavity and anastamose with superior epigastric artery
2. inferior epigastric artery-supplies majority of anterior abdominal wall
3. deep circumflex iliac artery-supplies lower abdominal wall, by inguinal ligament
components of the inguinal canal
all muscles of the anterior abdominal wall
inguinal canal
inferior aspect of the abdominal wall, above the fold of the leg, divided by the linea alba into right and left
muscular layers of the inguinal canal
1. external oblique-aponeurosis descends down to inferior wall forming the anterior border of the inguinal canal, inferior aspect of the external oblique is the inguinal ligament
2. internal oblique-becomes the conjoint tendon medially, some muscles become the cremaster muscle, forms the superior aspect of the inguinal canal
3. transversus-combines with the internal oblique to form the conjoint tendon, forms the superior aspect of the inguinal canal
inguinal hernia
checking for it is done by invaginating the skin between the scrotum and penis into the inguinal canal by going through the superficial inguinal ring, it is the most common hernia, but more common in males, can be congenital, “turn and cough”
transversalis fascia and inguinal canal
posterior aspect of the inguinal canal, behind the conjoint tendon
deep inguinal ring
a opening in the transversalis fascia in the lateral inguinal canal, is an exit point out of the abdominal cavity for the spermatic cord or round ligament
spermatic cord
contains vas deferens, cremaster muscle, testicular artery, and pampiniform plexus, exits abdominal cavity through the deep inguinal ring and travels down inguinal canal where it exits the inguinal canal through the superficial inguinal ring
round ligament
in females, exits the abdominal cavity through the deep inguinal ring and enters the inguinal canal, exits the inguinal canal through the superficial inguinal ring and attaches to the labia
inferior epigastric artery and the inguinal canal
crosses posterior to the inguinal canal, divides the canal into the medial and lateral parts, important in hernia surgery
ilioinguinal nerve and the inguinal canal
runs with the spermatic cord or round ligament (L1-L2)
descent of the testes
testes develop intra-abdominally in utero, testes then descend to the scrotum through the inguinal canal,
processeus vaginalis
communication part between the abdomen and the scrotum
tunica vaginalis
the processus vaginalis is obliterated and becomes the tunica vaginalis
inguinal hernias
two types:
1. direct-through the medial portion of the inguinal canal, medial to inferior epigastric, occurs from muscle weakness
2. indirect-through the lateral portion of the inguinal canal, usually through a patent processus vaginalis
abdominal aorta
continuation of the thoracic aorta, begins at the aortic hiatus as it enters the abdomen through the diaphragm at T12-L1 level, ends by dividing into 2 common iliac arteries above the pelvis at the L4-5 level
key to blood supply in the abdomen
collateral circulation
phrenic branches
first branches of the abdominal aorta, run inferior to the diaphragm, gives rise to the suprarenal arteries over the inferior surface of the diaphragm
celiac trunk
the first mesenteric branch of the aorta, arises at T12 level, three branches (left gastric, common hepatic, splenic)
left gastric artery
exits the celiac trunk to the left, courses to the right side of the stomach, blood supply to the lower esophagus (esophageal branches) and lesser curvature of the stomach
common hepatic artery
exits the celiac trunk to the right coursing behind the stomach to the liver, provides blood supply to the lower stomach, liver and duodenum, further branches include the right gastro-omental artery (greater curvature of the stomach), gastroduodenal artery (branches to the duodenum and pancreas) and proper hepatic artery (liver)
splenic artery
exits the celiac trunk to the left coursing behind the stomach, above the pancreas to the spleen, provides blood supply to the upper stomach, pancreas and spleen, further branches include the pancreatic branches along the superior portion of the pancreas, short gastric branches (greater curvature of the stomach) and left gastro-omental artery (greater curvature of the stomach)
superior mesenteric artery
second mesenteric branch of the abdominal aorta, arises at about the L1 vertebral level behind the pancreas
inferior pancreaticoduodenal artery
branch of the SMA, there are anterior and posterior versions, around C-loop of duodenum and head of pancreas, provides blood supply to the duodenum and head of pancreas
jejunal and ileal arteries
branches of the SMA, approximately 15-18 branches, found within the mesentery of the bowel, provide blood supply to the bowel
ileocolic artery
most distal branch of the SMA, found within the mesentery of the bowel, provide blood supply to the terminal ileum and cecum
right colic artery
first colonic branch of the SMA, found within the mesentery of the bowel, provide blood supply to the right colon
middle colic artery
last colonic branch of the SMA, found within the mesentery of the bowel, provide blood supply to the transverse colon
inferior mesenteric artery
third mesenteric branch of the abdominal artery, arises at approximately L3, inferior to the renal arteries
left colic artery
first branch of the IMA, found within the mesentery of the bowel, provide blood supply to the left colon, from splenic fixture to the sigmoid colon
sigmoid branches
second branch of the IMA, found within the mesentery of the bowel, provide blood supply to the sigmoid colon
superior rectal branch
terminal branch of the IMA, found within the mesentery of the bowel, provide blood supply to the superior rectum
celiac axis to SMA
collateral circulation around the duodenum/pancreatic head
1. common hepatic artery -> gastroduodenal artery -> superior pancreaticoduodenal artery
2. SMA-inferior pancreaticoduodenal artery
SMA to IMA
around the splenic flexure, collateral circulation
1. SMA-middle colic artery -> marginal artery of Drummond (near bowel wall) and Arc of Riolan (more proximal)
2. IMA-left colic artery
IMA to iliac arteries
collateral circulation around the rectum
1. IMA-superior rectal artery
2. iliac arteries-middle and inferior rectal arteries
mesenteric occlusive disease
found in patients with atherosclerotic disease, occlusion of one, two, or all of the mesenteric branches of the abdominal aorta, symptoms include weight loss, pain with eating, and/or acute abdomen with ischemic/necrotic bowel
renal arteries
usually arise off the abdominal aorta between the SMA and IMA (L2), provide blood to the kidneys, usually single branches but may have up to three branches to the kidney
gonadal arteries (testicular or ovarian)
varies as either off the aorta (L2) or renal branches, arterial supply to the testicles/ovaries
lumbar arteries
anterior and posterior, go the lumbar spine and spinal cord, arise off the aorta at each lumbar vertebral level, blood supply to the musculature in the back and to the spinal cord
anterior lumbar arteries
supplies anterior and lateral abdominal wall, passes around the abdominal wall, collaterizes to inferior epigastric artery in anterior abdominal wall
posterior lumbar arteries
supplies spinal cord and erector spinae muscles, spinal arteries arise from the posterior lumbar arteries
spinal arteries from the posterior lumbar arteries
give rise to radicular arteries (at each nerve level), the largest radicular artery (Spinal Artery of Kiewicz) supplies the inferior spinal cord
abdominal aortic aneurysm
dilation of the abdominal aorta, usually develops below the renal arteries, but can be found at any level, risk of rupture increases when it gets larger than 5 cms
inferior vena cava
begins at the confluence of the common iliac veins, approximately at L5, ascends to the right of the abdominal aorta, runs posterior to the liver, through the diaphragm into the right atrium
renal veins
branch into the IVC from both kidneys, usually one branch, veins run anterior to renal arteries, usually at L2, runs posterior to SMA
hepatic veins
three branches (right, middle and left) that drain directly into the IVC along the superior aspect of the liver
deep venous thrombosis (DVT)
often occur in the pelvis or lower extremity veins, risk is that clot will embolize to lung becoming a pulmonary embolism (PE)
prevention-placement of Greenfield filter into IVC, usually below the renal veins
lumbar veins
four to five paired branches from each vertebral level, much variation in location, usually unite into the ascending lumbar vein
right ascending lumbar veins
becomes the azygos vein, enters thorax and central circulation
left ascending azygos vein
becomes the hemiazygos vein, enters thorax and central circulation
mesenteric drainage through hepatopedal circulation
allows venous drainage from mesentery of the bowel to be cleared by the hepatic system before systemic drainage
inferior mesenteric vein (IMV) and hepatopedal circulation
drains sigmoid and descending colon, unites with the splenic vein
superior mesenteric vein (SMV) and hepatopedal circulation
drains small bowel, right and transverse colon, unites with splenic vein and the IMV to form the portal vein
gastric veins and hepatopedal circulation
drains stomach and drains into the portal vein
liver cirrhosis and esophageal/gastric varices
cirrhosis causes scarring of the liver, leads to a decrease in hepatopedal flow and increase pressure in the venous system, this causes the venous system to distend, leading to engorged veins in esophagus, stomach, spleen and intestines (portal hypertension)
function of the stomach
storage of food during intake and provides reservoir for food for mixing with digestive enzymes, it is a distendible organ up to 2-3 L
aspiration of the stomach
stomach can hold liquid/air for long periods of time, esp. during illness and trauma, patients may vomit and aspirate large volumes especially when trying to intubate for airway management
divisions of the stomach
beings at the gastro-esophageal junction, then the fundus, then the body, then the antrum, then the pylorus
gastro-esophageal junction
cardiac orifice, below the diaphragm
fundus
superior portion of the stomach above the orifice
body
between the fundus and antrum, from the cardiac orifice to the Vein of Mayo, lower 1/3 of stomach
antrum
acid producing portion of the stomach, from vein of Mayo to pyloric canal
pylorus
canal and sphincter, end of the stomach, thickened circular muscle that control gastric emptying
hiatal hernia
herniation of the fundus and/or fundus through the esophageal hiatus, may increase gastro-esophageal reflux because of disruption of gastro-esophageal junction
peptic ulcer disease (PUD)
use H2 blockers to alleviate, before H2 blockers needed surgery to stop bleeding and perforation (antrectomy (removing antrum) and vagotomy (removing vagus nerves), vagotomy may lead to problems with gastric emptying
pyloring stenosis
hypertrophy of the pyloric muscle that causes a gastric outlet obstruction, in infants 2-8 weeks old, boys more frequent, treatment is a pylorotomy (cutting of the muscle to open the pyloric canal)
position of the stomach
sits in the upper abdomen, left liver lobe covers the upper stomach, fundus of the stomach sits next to the diaphragm and spleen, greater omentum attaches along the greater curvature, pancreas sits behind the stomach, area behind the stomach is the lesser sac
pancreatic pseudocyst
a complication of pancreatitis, treatment includes draining it into the stomach (cystgastrostomy)
arterial supply of the stomach
provided by all three branches of the celiac axis
left gastric artery and the stomach
enters the stomach along the lesser curvature in hepatogastric ligament (mesentery along the lesser curvature), supplies the upper stomach and lower esophagus
right gastric artery and the stomach
branch of the common hepatic artery, enters the stomach along the lesser curvature in hepatogastric ligament, supplies the antrum and pylorus
right gastro-omental artery and the stomach
branch of the gastroduodenal artery, enters the stomach along the greater curvature of the stomach, supplies the greater curvature from antrum to mid body of stomach
short gastic arteries and the stomach
branches of the splenic artery, enters the stomach along the greater curvature at the fundus and upper body in the gastrolienal ligament, supplies the greater curvature from the fundus to the upper body of stomach
left gastro-omental artery and the stomach
branch of the splenic artery, runs inferior to the short gastric arteries, enters the stomach along the greater curvature at the fundus and upper body in the gastrolineal ligament, anastomoses with the right gastro-omental, supplies the greater curvature from fundus to upper body of the stomach
venous drainage of the stomach
parallels the supply of the stomach, veins coalesce and drain into the portal vein which drains into the liver
1. right and left gastric veins drain into the portal vein
2. right gastro-omental vein drains into the SMV
3. left gastro-omental vein drains into the splenic vein
lymphatic drainage of the stomach
1. left gastric lymph nodes (along left gastric artery)
2. gastro-omentla lymph nodes (along the greater curvature)
3. pyloric lymph nodes anterior surface of the pancreas (near the pylorus)
4. pancreaticolienal lymph nodes (along splenic artery, superior aspect of pancres)
5. right gastric lymph nodes (along right gastric artery)
where do lymph nodes in the stomach drain?
drain into the celiac axis lymph nodes
gastric lymphoma
lymphoma that develops in the stomach wall, involves multiple lymph nodes
innervation of the stomach
left and right branches of the vagus nerve (CN X), provides motor to stomach and stimulation for acid release (specifically the antrum)
left vagus nerve and the stomach
left vagus nerve becomes the anterior vagus nerve at the stomach, enters along the lesser curvature and branches to the anterior stomach, liver and duodenum
right vagus nerve and the stomach
becomes the posterior vagus nerve at the stomach, enters the lesser curvature and branches to the posterior stomach
liver
largest gland in the body, accounts for 2% of the body weight
functions of the liver
1. glycogen storage
2. produces bile
3. protein production (coagulation factors)
4. filter of enteric circulation
diaphragmatic surface of the liver
superior, posterior and right lateral aspect that lay on the diaphragm
bare area of the liver
portion of the diaphragmatic surface of the liver, in the posterior liver, liver is in direct contact with the diaphragm, IVC runs through here
visceral surface of the liver
inferior portion of the liver, lies on the anterior surface of the stomach, first and second portion of the duodenum, gallbladder, lesser omentum, right colic flexure of colon (hepatic flexure, where ascending colon becomes the transverse colon)
visceral surface landmarks
H-shaped fissures that define the liver into 4 lobes, the crossbar of the H is the porta hepatis
porta hepatis
fissure in the center of the inferior liver, contains the portal vein, hepatic artery, common bile duct, lymphatics and hepatic nerve plexus
right lobe of the liver
to the right of the falciform ligament, has its own arterial, venous, and bilary system, has two smaller lobes within it (quadrate and caudate lobe)
left lobe of the liver
to the left of the falciform ligament, has its own arterial, venous, and bilary system
quadrate lobe of the liver
lies between the gallbladder and the falciform ligament inferior to the porta hepatis
caudate lobe
lies between the inferior vena cava and the falciform ligament/ligamentum venosum
falciform ligament
develops from the umbilicus and attached to anterior abdominal wall, terminates in the bare area as the coronary ligament, divides the liver into left and right lobes, antepartum (contains the umbilical vein), postpartum (umbilical vein becomes the ligamentum teres)
cirrhosis of the liver
can increase venous pressure in the abdomen, back pressure can lead to the ligamentum teres to become patent again, can see “caput medusa” (prominent periumbilical vein due to portal hypertension
coronary ligament
begins at the superior aspect of liver where the falciform ligament terminates, surrounds the bare area, left lateral aspect is the left triangular ligament while the right lateral aspect makes the right triangular ligament
hepatogastric ligament
begins at the left triangular ligament and terminates in the lesser curvature of the stomach, part of the lesser omentum, contains the left and right gastric arteries and veins, gastric lymphatics
hepatoduodenal ligament
begins along the caudate lobe and terminates along the C loop of the duodenum, part of the lesser omentum, contains the peripancreatic lymphatics
lesser omentum
includes the hepatogastric and hepatodudoenal ligaments, portal tirad runs along the free edge of the lesser omentum
portal triad
1. portal vein
2. common bile duct
3. proper hepatic artery
blood supply of the liver
is considered to have a double blood supply
1. hepatic artery provides approximately 30% of blood supply
2. portal vein provides approximately 70% of blood supply
common hepatic artery
branch of the celiac trunk, passes to the right of the stomach and along first portion of the duodenum, gives off gastroduodenal and right gastroepiploic branches and becomes proper hepatic artery
proper hepatic artery
part of the portal triad, divides into right and left hepatic arteries
variations in the proper hepatic artery
approx. 10% of left hepatic arteries will arise off left gastric artery (replaced left hepatic), and approx. 1-2% of right hepatic arteries will arise off the superior mesenteric artery (replaced right hepatic)
portal vein
part of the portal triad, formed by the confluence of the SMV and IMV and the splenic vein, runs posterior to the bile duct and proper hepatic artery, divides into right and left portal veins
hepatopedal flow
all venous drainage from bowel is cleared by the liver, carcinomas from the bowel can spread to liver, manifested by metastatic lesions in liver through hematogenous spread
superior hepatic veins
located at superior aspect of liver, three superior hepatic veins drain into IVC, right, middle (drains caudate lobe) and left
inferior hepatic veins
located along posterior aspect of liver, drain into the IVC, 6 to 18 branches that drain the caudate, quadrate and right lobe
liver transplants
replace the entire liver for cirrhosis due to alcoholism and hepatitis, when replacing the liver, surgeon will the IVC to save the multiple posterior branches
lymphatic drainage of the liver
superior and anterior portions drain to parasternal lymph nodes, inferior portions drain to hepatic lymph nodes in the porta hepatis and gastric lymph nodes in the lesser momentum
bilary system
bile is made by the liver and drains through the bilary system, small intralobular bile ducts coalesce to form larger ducts
right and left hepatic ducts
drain bile from the right and left lobes, form the common hepatic duct at the superior aspect of the porta hepatis
common hepatic duct
after forming by the right and left hepatic ducts, travel approx. 3-5 cm where the cystic duct from the gallbladder drains into the common hepatic duct
common bile duct
formed after the cystic duct joins the common hepatic duct, travels down the porta hepatis into the head of the pancreas, joins the pancreatic duct, drains into the second portion of the duodenum through the sphincter of Oddi
common bile duct stone
gallstones from in the gallbladder, stones can exit the gallbladder through the cystic duct and block the common bile duct (choledocholithiasis), can cause pain, jaundice, nausea, vomiting, evaluated by ERCP (endoscopic retrograde cholangiopncreatorgram
gallbladder
pear shaped organ attached to the right lobe of the liver, stores bile and drains when the stomach stimulates gallbladder to empty, through CCK (cholecystekinase)
portions of the gallbladder
1. fundus-wide end of gallbladder
2. body-main portion of gallbladder
3. neck-narrow, tapered portion of gallbladder
4. cystic duct-continuous with neck, drains into common hepatic duct
cystic duct
position can vary considerably, relation to cystic artery, common bile duct and right hepatic artery can lead to injuries if care is not taken
cystic artery
arises from the right hepatic artery, multiple variations in position in relation to cystic duct
venous drainage of the gallbladder
drains into the portal vein or liver direcetly
lymphatic drainage of the gallbladder
cystic lymph node (Node of Cliquot) found at confluence of cystic and common hepatic duct, drains ultimately into hepatic and celiac lymph nodes
bilary colic
gallstones form in the gallbladder, can lodge in the neck or cystic duct leading to colicky pain in the right upper quadrant, treatment is a cholecystectomy, usually laparoscopic
functions of pancreas
act as a both an exocrine and endocrine gland, external excretion of pancreatic enzymes into the duodenum through the pancreatic duct, internal secretions of insulin and glucagon into blood directly
pancreatic position
pancreas lies in the retroperitoneum, behind the stomach in the lesser sac, over the spine, the duodenum runs along the right portion and inferior portion, the tail of the pancreas ends in the hilum of the spleen in the left upper quadrant
pancreatic trauma
can occur with seat belt injuries, back injuries and handlebar injuries, gland often transected over the spine, treatment can include removal of distal pancreas
head of pancreas
within the C loop of the duodenum, posteriorly, the head lays on the IVC and right renal vessels
common bile duct anatomy
comes down from porta hepatis and enters the head of pancreas, joins with the pancreatic duct and exits into the duodenum
uncinate process of the pancreas
part of the head of the pancreas, lies inferior to the superior mesenteric vessels and rests against the aorta posteriorly
neck of the pancreas
continuous with the head of the pancreas, approx. where the superior mesenteric vessels cross the pancreas
body of the pancreas
continuous with the neck of the pancreas, portion of pancreas to left of aorta and extends superiorly, has an anterior, posterior, and inferior surface
tail of the pancrease
continuous with the body of the pancreas, crosses through the lienorenal ligament with the splenic vessels, terminates in the hilum of the spleen
embryology of the pancreas
pancreas develops as two separate buds, the buds fuse to form the pancreas
1. dorsal bud-becomes main gland
2. ventral bud-forms uncinate process
formation of the pancreatic duct
main pancreatic duct begins in the tail of the pancreas, formed within the dorsal pancreatic bud, proximally, the uncinate process forms the proximal pancreatic duct, main duct becomes Y shaped at the uncinate process, proximal part of the dorsal pancreatic duct is the accessory pancreatic duct, much variation in formation is found in the pancreatic gland
main pancreatic duct
joins with the common bile duct to form the hepatopancreatic ampulla (ampulla of vater), drains into the duodenum through the choledochal sphincter (Sphincter of Oddi)
accessory pancreatic duct
usually is connected to the main pancreatic duct (90%), can be a separate duct which drains into the duodenum through the minor duodenal papilla
pancreatic cancer
usually develops in the head of the pancreas, presents with back pain, jaundice and weight loss, symptoms often occur with the blockage of the common bile duct where it traverses the pancreas
pancreatic blood supply
three sources of blood supply:
1. common hepatic artery -> gastroduodenal artery -> superior pancreaticoduodenal arteries
2. superior mesenteric artery -> inferior pancreaticoduodenal arteries
3. splenic artery > dorsal pancreatic artery
superior pancreaticoduodenal (PD) arteries
supplies head of the pancreas and C loop of duodenum
inferior PD arteries
supplies the head of the pancreas
dorsal pancreatic artery
supplies the neck, body and tail of pancreas
venous drainage of the pancreas
most of the pancreas drains into the splenic vein
draining lymph nodes of the pancreas
1. pancreaticosplenic-along superior aspect
2. pyloric-along the head of the pancreas
3. celiac-along draining veins
spleen
largest lymph tissue in the body
functions of the spleen
filter the blood of old red cells and clear antigens
overwhelming post splenectomy sepsis
patients who have a splenectomy are at increased risk of having an overwhelming infection because of lack of antigen filter, can occur up to 42 years after splenectomy
spleen anatomy
located in the left upper abdomen, against the diaphragm, behind the stomach, attaches to the stomach via the gastrolienal ligament and attaches to the left kidney via the lienorenal ligament
spleen poles
divided into superior and inferior poles, divided by the hilum of the spleen (central portion where blood vessels enter and exit)
splenic artery
branch of the celiac trunk, runs along the superior aspect of the pancreas to enter the splenic hilum, divides into 3-5 branches in the hilum to supply the spleen, all arteries are end arteries, no collateral circulation
splenic vein
formed by smaller veins draining the splenic parenchyma, runs along the superior aspect of the pancreas, unites with the superior mesenteric vein to form the portal vein
sickle cell disease
red cells “sickle” and will filter out in the spleen, these will clog the end arteries and lead to infarction, sickle cell patients will have autosplenectomy increasing the risk of infection
splenic trauma
spleen can be injured in any trauma, most common intra-abdominal organ to be injured, treatment may be non-operative or require repair or removal of spleen
duodenum
first portion of small intestine, begins after pylorus of the stomach, ends at the ligament of Trietz (the beginning of the jejunum) shortest portion of the small bowel
duodenum position
except for the first 2-3 cm, is a completely retroperitoneal structure
first portion/division of the duodenum
is the intraperitoneal portion (AKA duodenal bulb), in continuity with the pylorus, approx. 2-3 cm in length, the common bile duct, gastroduodenal artery and IVC run posterior to this portion
duodenal ulcer disease
ulcers can develop in the duodenal bulb due to increased acidity entering the bulb from the stomach, can perforate or bleed, perforations are often anterior (intraperitoneal) while bleeding often is from the gastroduodenal artery requiring ligation
second portion of the duodenum
referred to as the C loop, continuous with the first portion, where the duodenum becomes retroperitoneal, approx. 8-10 cm in length, where the pancreatic and common bile duct drain into the duodenum through the ampulla of Vater
third portion of the duodenum
referred to as the horizontal portion, in continuity with the second portion, ends wehre the superior mesenteric vessels cross, approx. 5-8 cm in length, where the duodenum proceeds horizontally over the spine from right to left
fourth portion of the duodenum
referred to as the ascending portion, in continuity with the third portion, begins to the left of the superior mesenteric vessels, ends at the ligament of Trietz, approx. 2-3 cm in length, duodenum proceeds superiorly to the left side of abdomen and acute turn where it becomes the jejunum
blood supply to the duodenum
superior pancreaticoduodenal artery from the gastroduodenal artery, inferior pancreaticoduodenal artery from the superior mesenteric artery
venous drainage from duodenum
most venous drainage is into the superior mesenteric vein, entering the portal system
lymphatic drainage of duodenum
drain primarily into pancreaticoduodenal lymph nodes, ultimately draining into the celiac lymph nodes
malrotation
the intestine exits the fetus at 7-8 weeks development and then returns in a rotated position, present with bilious vomiting to septic secondary to mid gut volvulus
jejunum and ileum
second and third portions of the small intestine, begins at the ligament of Trietz, ends at the ileocecal valve, no obvious demarcation where jejunum becomes ileum, both total approx. 6-7 meters (first 2/5ths thought to be jejunum)
external differences between the jejunum and ileum
1. jejunum is usually thicker and more muscular
2. jejunum is the more proximal portion so resides in the upper abdomen
3. ileum is more distal so resides in the pelvis and lower abdomen
internal differences between the jejunum and ileum
circular folds (plicae circulares) in the mucous membrane are large and well developed in the jejunum, provides more absorptive surface
mesentery and the jejunum and ileum
mesentery suspends the two and carries blood vessels and lymphatics, root of mesentery emanates from superior mesenteric vessels and fans out with the bowel along the edge of the mesentery
blood supply of the small intestine
entire blood supply to jejunum and ileum comes from the superior mesenteric artery, SMA provides 15-18 branches to jejunum and ileum, arteries unite to form arterial arcades, from the arterial arcades, vasa recta arise, vasa recta then enter bowel on the mesenteric border
venous drainage of the small intestine
drains into the superior mesenteric vein, veins and venules follow arterial supply
lymphatic drainage of small intestine
lacteals are lymphatics in the intestinal villi, lacteals drain into a lymph vessel plexus in the mesentery, plexus drains into mesenteric lymph nodes, three levels of mesenteric lymph nodes:
1. next to intestine
2. along arterial arcades
3. along SMA
innervation of the small intestine
derived from the vagus (parasympathetic, motility) and splanchnic nerves, sympathetic from superior mesenteric ganglion (T9-T10), pain is mediated through the thoracic segments not the vagus
Meckel’s diverticulum
embryologically, omphalomesenteric duct drains intestinal contents from distal small bowel through umbilicus in the womb, the diverticulus is a 3-6 cm long pouch found in the ileum within 50 cm of the ileocecal valve, may have fibrous cord connecting to umbilicus
large intestine
begins at the ileocecal valve, at the cecum, ends at the anus, approx. 1.5 meters long
functions of large intestine
absorb water from feces and storage of feces
features of the small intestine
1. teniae coli-three longitudinal muscle bands that run along the entire colon
2. haustra coli-permanent sacculations between teniae involving the circular muscle
3. appendices epiploicae-fatty appendages that are attached to the teniae
cecum
begins at ileocecal valve, is first portion of ascending (right) colon, sac like structure, blood supplied by the ileocolic artery (branch of the SMA)
vermiform appendix
vestigial portion of GI tract, unknown function but it does have some lymphoid tissue, begins at confluence of teniae coli, at base of cecum, blood supplied by the ileocolic artery
ascending colon
begins at cecum, ends at the hepatic or right flexure, approx. 12-20 cm long, lies retroperitoneally, along right side of abdomen, blood supplied by the right colic artery
transverse colon
begins at the hepatic or right flexure, ends at the splenic or left flexure, approx. 30-50 cm long, lies intraperitoneally, draped across abdomen from right to left side of abdomen, blood supplied by middle colic artery (branch of the SMA)
descending colon
begins splenic or left flexure, ends at the brim of pelvis, becomes sigmoid colon, approx. 15-20 cm long, lies retroperitoneally, along left side of abdomen, blood supplied by left colic artery, branch of the IMA
sigmoid colon
begins pelvic brim (S-shaped loop), ends at the sacral promontory, becomes rectum, approx. 15-80 cm long, lies intraperitoneally, in the left lower quadrant, blood supplied by the sigmoid arteries (2 or 3) branch of the IMA
diverticuli
outpouchings of mucosa between teniae coli in colon, can occur anywhere in the colon but most commonly in the sigmoid colon, complications include infection (diverticulitis) or bleeding (diverticular hemorrhage)
rectum
begins at the sacral promontory, ends at the anus, approx. 12-15 cm long, lies retroperitoneally, in the pelvis, blood supplied by the superior rectal artery (branch of IMA) and middle and inferior rectal arteries (branches of internal iliacs)
differences in the rectum
there are internal folds, transverse rectal folds, are continuations of teniae, aids in supporting the feces, rectum functions to store feces before defecating, since the rectum goes through the pelvic floor, there are no diverticuli
lymphatic drainage of cecum
periappendiceal LN -> superior mesenteric LN
lymphatic drainage of ascending colon
paracolic LN -> superior mesenteric LN
lymphatic drainage of transverse colon
superior mesenteric LN
lymphatic drainage of descending colon
inferior mesenteric LN
lymphatic drainage of sigmoid colon
inferior mesenteric LN
lymphatic drainage of rectum
superior portion-pararectal LN -> inferior mesenteric LN
inferior portion-internal iliac LN
inervation of colon
supplied by SMA (superior mesenteric plexus) and IMA (inferior mesenteric plexus)
innervation of rectum
middle rectal plexus -> from inferior hypogastric plexus
anus
terminal portion of GI tranct, approx. 2.5-5 cm in length, begins at the puborectalis muscle, surrounded by internal and external sphincters, internal anal sphincter is involuntary, external anal sphincter is voluntary
innervation of anus
external anal sphincter, inferior rectal nerve
anus internal anatomy
superior portion-mucosa similar to rectum, has folds called anal columns
inferior portion-anal columns end in anal valves
superior and inferior portions separated by pectinate line
blood supply to the anus
superior rectal artery supplies the superior part of the canal
inferior rectal arteries supply inferior part of the canal
anal pathology
perirectal/perianal abscesses
hemorrhoids: internal (superior rectal vein), external (inferior rectal vein)