Abdomen: Viscera Overview/Foregut Flashcards
Right costal margin
- Liver
- Gallbladder
Left costal margin
- Stomach
Ribs protect
- Spleen
- Part of the liver
- Kidneys
- Rib frx puts certain viscera at risk (liver, spleen, kidneys)
Foregut extends from
- Esophagus > 2nd part of duodenum
Foregut arterial supply
- Branches from the celiac trunk
Midgut extends from
- 2nd part of duodenum > distal 1/3 of transverse colon
Midgut blood supply
- Branches from superior mesenteric artery
Hindgut extends from
- Distal 1/3 transverse colon > upper anal canal
Hindgut blood supply
- Branches from the inferior mesenteric artery
The GI tract is largely drained by
- The hepatic portal venous system
Foregut innervation (sympathetic)
- Greater splanchnic nerve (T5-T9) > celiac ganglia
Midgut innervation (sympathetic)
- Lesser splanchnic nerve (T10-T11) > superior mesenteric ganglion, aorticorenal ganglia
Hindgut innervation (sympathetic)
- Lumbar splanchnic nerve (L1,L2) > inferior mesenteric ganglion
Least splanchnic nerve (T12) innervates
- Aorticorenal and renal plexus
Postsynaptic sympathetic fibers travel in _____ to destination
- Periarterial plexuses
Postsynaptic sympathetic fibers traveling in periarterial plexuses go to
- Renal plexus, hepatic plexus, etc.
Adrenal gland (medulla) receives
- Direct innervation from presynaptic fibers
- Exception of postsynaptic sympathetics destination pathway
Sympathetic primary functions in abdomen
- Altering vasomotor tone
- Slowing peristalsis
Presynaptics travel in (parasympathetic innervation of abdomina viscera)
- Vagus nerve (A/P vagal trunks)
- Pelvic splanchnic nerves
Vagus nerve innervation (presynaptic parasympathetic)
- Innervates lower esophagus to left colic flexure
- Foregut and midgut
Pelvic splanchnic nerves have nothing to do with
- Sympathetics
Pelvic splanchnic nerves are derived from
- Spinal segments S2-4
Pelvic splanchnic nerves travel through
- Inferior hypogastric plexus
Pelvic splanchnic nerves innervate (presynaptic parasympathetic)
- Descending colon to rectum (hindgut)
- Pelvic organs
Vagus and pelvic splanchnic (pre/para) synapse on
- Postsynaptic neuron on/in wall of viscera
Parasympathetic primary functions in abdomen
- Promote peristalsis and secretion
Visceral Afferents (Sensory)
- Unconscious reflexes
- Nociception
Visceral afferents (sensory) of foregut and midgut travel in
- Vagus nerve
Visceral afferents (sensory) of hindgut travel in
- Pelvic splanchnic nerves
Visceral afferent fibers conveying nociception follow
- Follow sympathetic fibers
- Travel in a reverse course to spinal cord
Visceral afferent fibers conveying nociception from foregut follow
- Foregut > greater splanchnic nerve
Visceral afferent fibers conveying nociception from midgut follow
- Midgut > lesser splanchnic nerve
Visceral afferent fibers conveying nociception from hindgut follow
- Hindgut > lumbar splanchnic nerves
- Descending colon
- Proximal ½ sigmoid colon
Exception to visceral pain afferents
- Midpoint of sigmoid colon to rectum
- Pain afferents follow parasympathetic fibers
- Pelvic splanchnic to cord levels S2-4
Abdominal esophagus
- Begins at T10 at the esophageal hiatus
- Joins stomach at cardiac region
Parts of the stomach
- Cardia
- Fundus
- Body
- Pylorus
Fundus of the stomach is positioned
- Against left dome of diaphragm
Parts of the pylorus
- Outflow region
- Pyloric antrum
- Pyloric canal
- Pyloric sphincter
- Pyloric orifice
Pyloric sphincter
- Thickened layer of smooth muscle
- Regulates release of chyme into duodenum
Interior of the stomach contains
- Gastric folds (rugae)
Stomach position and supine surface projection depends on
- Position
- Body type
- Fed-state
Intraperitoneal organ
- Covered by peritoneum (except at the “bare area”)
- Location of gastrophrenic ligament
Organs located anterior to the stomach
- Left lobe of liver
- Diaphragm
- Anterior abdominal wall
Organs located posterior (posterolateral) to the stomach
- Lesser sac
- Pancreas
- Left kidney
- Adrenal gland
- Spleen
Organs located superior to stomach
- Diaphragm
Organs located inferior to stomach
- Transverse colon
- Transverse mesocolon
Arterial bloody supply to stomach is from the
- Celiac trunk
Arteries supplying the stomach
- Rt. Gastric (RG)
- Lt. Gastric (LG)
- Rt. Gastroepiploic (Rt. GEP)
- Lt. Gastroepiploic (Lt. GEP)
- Short Gastric (SG)
Veins (same names as the arteries) drain into
- Portal venous system
Other branches supplying trunk
- Common hepatic artery (CHA)
- Hepatic artery proper (HAP)
- Gastroduodenal (GD)
- Splenic (Spl)
Spleen (lien) function
- Prenatal hmatopoiesis
- Storage and destruction of RBC and platelets
- Iron and globin recycling
- Immune function
Spleen (lien) location
- Left upper quadrant
- Lies on diaphragm (ribs 9-11)
- Recumbent position
- Long axis parallels rib 10
Spleen (lien) can be injured by
- Rib fracture (lies on diaphragm/ribs 9-11)
Two surfaces of the spleen
- Diaphragmatic
- Visceral
Diaphragmatic surface of spleen (posterior, superior)
- Against diaphragm
Visceral surface of spleen
- Abuts organs (stomach, left kidney, left colic flexure)
- Left colic flexure is inferior
- Left kidney, stomach are medial
- Stomach is anteromedial
Spleen is considered
- Intraperitoneal
Ligaments of the spleen
- Gastrosplenic ligament
- Splenorenal ligament
Gastrosplenic ligament
- Ggreater curvature to spleen
- Contains short gastric vessels
Splenorenal ligament
- Spleen to kidney
- Contains splenic vessels and tail of pancreas
- Splenic artery
Splenic artery
- Runs along upper border of pancreas
- Very tortuous
- Multiple branches enter spleen
Liver is considered
- Intraperitoneal
Liver function
- Exocrine secretion (bile production)
- Endocrine secretion (IGF-1)
- Receives blood from GI tract via portal vein (nutrient rich, except for fat)
- Synthesis of proteins (clotting factors, albumin, etc)
- Stores glycogen
- Modifies toxic compounds (drug metabolism)
Two surfaces of liver
- Diaphragmatic
- Visceral
Diaphragmatic surface (anterior, superior, posterior) of liver
- Against diaphragm
- Separates it from pericardial and pleural cavities
- Subphrenic recesses
Subphrenic recesses (diaphragmatic surface of liver)
- Between liver and diaphragm
Visceral surface (posterior, inferior) of liver contains
- Right colic flexure
- Right kidney
- Stomach
- Duodenum
- IVC
Recesses of the visceral surface of liver
- Subhepatic recess
- Hepatoreneal recess
Diaphragmatic surface of liver is covered in
- Peritoneum (except for bare area)
- Peritoneum reflects off as the coronary & triangular ligaments
- Groove for IVC
Coronary & triangular ligaments
- Attaches liver to diaphragm
Falciform ligament
- Attaches to diaphragm and anterior ab wall
- Separates subphrenic spaces into left and right
Ligamentum teres hepatis (round ligament of the liver)
- Inferior edge of the falciform ligament
- Obliterated umbilical vein (nutrient rich blood in fetus)
- Paraumbilical veins pass through
Paraumbilical veins
- Pass through falciform ligament
- Connect superficial veins to portal venous system
Visceral surface of liver is covered in
- Covered in peritoneum
- Peritoneum covers gallbladder
Porta hepatis (transverse fissure of liver) contains
- Hepatic portal vein (posterior)
- Hepatic artery (left)
- Hepatic ducts (right)
- Hepatic nerve plexus
- Lymphatics
Visceral surface of the liver contains
- Porta hepatis
- Fissures
- Impressions from neighboring viscera
Fissures of the visceral surface of liver
- For round ligament of liver
- Ligamentum venosum
Ligamentum venosum
- Remnant of ductus venosus
- Shunts blood from umbilical vein to IVC
Anatomical lobes of the liver
- Left and right lobes
- Divided by falciform ligament
Functional subdivision of the liver is based on
- Branching of portal vein, hepatic artery and vein, and hepatic duct
Gall bladder function
- Stores and concentrates, and releases bile
- Covered by peritoneum
Gall bladder location
- Located in fossa on visceral surface of liver
- Anterior/superior to duodenum
- Level of costal margin of rib 9
- Transpyloric plane
Biliary ducts function
- Convey bile from liver/gallbladder to 2nd part of duodenum
Biliary ducts (names)
- Left and right hepatic ducts
- Common hepatic duct
- Cystic duct
- Common bile duct
Biliary duct pathways
- Common bile duct passes posterior to duodenum
- Joins main pancreatic duct (hepatopancreatic ampulla)
- Open on the greater duodenal papilla (2nd part of duodenum)
Common bile duct passes
- Posterior to duodenum
Common bile duct joins with
- Main pancreatic duct
- Forms hepatopancreatic ampulla
Main pancreatic duct opens on the
- Greater duodenal papilla
- Located in 2nd part of duodenum
Spiral valve (fold)
- Keeps cystic duct open to allow bile flow
- Prevents excessive release
Sphincter of Boyden
- Sphincter of the common bile duct
Sphincter of Oddi
- Sphincter of ampulla
Blood supply to liver
- Dual blood supply
- Portal vein
- Hepatic arteries
Portal vein conducts
- 75-80% of blood to liver
- All nutrients absorbed from GI tract, except lipids
Hepatic arteries conduct
- 20-25% of blood to liver
Venous drainage of liver
- Left, right, and middle hepatic veins drain into IVC
Blood supply to gallbladder
- Cystic artery
Cystic artery
- Commonly branches from right hepatic (variation)
- Post. to common hepatic duct (most common), can pass anterior
- Cystohepatic triangle (of Calot)
Cystohepatic triangle (of Calot)
- Liver surface
- Cystic and common hepatic ducts
Right hepatic and superior pancreaticoduodenal supply
- Hepatic duc
Cholelithiasis
- Gallstones
Choledocholithiasis
- Bile duct stones
Cholecystitis
- Inflammation of the gallbladder
Cholecystectomy
- Removal of gallbladder
If pancreatic duct is blocked, patient will experience
- Pancreatitis (inflammation of pancreas)
Gallbladder referred pain is typically seen in
- Right shoulder
- Right upper quadrant and back
- Upper right quadrant
Gallbladder referred pain in the right shoulder involves
- Diaphragmatic parietal peritoneum irritation, innervated by phrenic (C3-5)
- Overlap with sensory from shoulder (supraclavicular nerves, C3,4)
Gallbladder referred pain in the right upper quadrant and back involves
- Pain sensory fibers traveling in greater splanchnic nerve (T5-9) overlap with dermatomal innervation
Pancreas
- Exocrine/endocrine organ
- Mostly retroperitoneal
- Head is surrounded by duodenum
- SMA and SMV enclosed by pancreas
The portal vein is formed
- Behind the neck of the pancreas
The neck and the uncinate process of the pancreas encolse
- SMA and SMV
Parts of the pancreas
- Head
- Uncinate process
- Neck
- Body
- Tail
Organs located anterior to the pancreas
- Lesser sac
- Stomach
Organs located posterior to the pancreas
- IVC
- Aorta
- SMA
- Left crus of diaphragm
- Left kidney
- Suprarenal gland
Splenic artery runs along
- Superior surface of pancreas
Splenic vein runs on
- Posterior surface of pancreas
Pancreatic ducts
- Main pancreatic duct
- Accessory pancreatic ducts
Main pancreatic duct runs
- From tail to head
Blockage of the main pancreatic duct
- Can cause pancreatitis
Main pancreatic duct joins with
- The common bile duct
- Forms hepatopancreatic ampulla
Hepatopancreatic ampulla is also called
- Ampulla of Vater
Hepatopancreatic ampulla (ampulla of Vater)
- Opens in the 2nd part of duodenum on greater duodenal papilla
Smooth muscle sphincters
- Sphincter of the pancreatic duct
- Sphincter of the bile ducts
- Hepatopancreatic sphincter
Hepatopancreatic sphincter is also called
- Sphincter of Oddi
Sphincter of Oddi is around
- Hepatopancreatic ampulla
Accessory pancreatic duct
- Not always present
- Variation in drainage
Accessory pancreatic duct opens on
- The lesser (minor) duodenal papilla
- In the 2nd part of duodenum
Accessory pancreatic duct is located
- Superior to greater (major) duodenal papilla
The pancreas is supplied (arterial) by branches of
- Gastroduodenal
- SMA
- Splenic
Branches from gastroduodenal artery that supply the pancreas
- Anterior Superior Pancreaticoduondenal
- Posterior Superior Pancreaticoduondenal
Branches of the SMA that supply the pancreas
- Anterior Inferior Pancreaticoduodenal
- Posterior Inferior Pancreaticoduondenal
Branches of the splenic artery that supply the pancreas
- Dorsal pancreatic
- Greater pancreatic
- Caudal pancreatic
- Inferior pancreatic (continuation of dorsal pancreatic)
