Flashcards in GI Anatomy - Jaundice Deck (74):
Yellowing of the slcera and skin
Caused by increase in the blood levels of bilirubin
Normal by-product of the break down of red blood cells
Breakdown mainly occurs in the spleen
Where does breakdown of bilirubin primarily occur?
What is the function of bilirubin in the liver, gallbladder and small intestine?
Liver - used to form bile
Gallbladder - plays role in storage and concentration of bile
Small Intes. - important or normal absorption of fats from the small intestine
(pancrease also excretes digestive enzymes into duodenum for digestion)
How does bile travel from the liver to the duodenum?
= a set of tubes connecting the liver to the 2nd part of the duodenum (bile travels through)
What is the surface anatomy of the liver?
Located in RUQ
Protected by ribs 7-11
Location changes in breathing
How many anatomical and functional lobes does the liver have?
Anatomical - 4
Functional - 8 (related to vasculature and bile drainage)
What lobes are visible from the anterior and posterior view of the liver?
Anterior - right and left lobe
Posterior - Right, Left, Quadrate (inferior), Caudate (superior)
What ligament divides the right and left lobe of the liver on the anterior surface?
What is the Round ligament of the liver?
Remnant of the umbilical vein
= a degenerative string of tissue that exists in the free edge of the falciform ligament of the liver. The round ligament divides the left part of the liver into medial and lateral sections.
Site of entrance for portal triad structures
= The porta hepatis is a deep fissure in the inferior surface of the liver through which all the neurovascular structures (except hepatic veins) and hepatic ducts enter or leave the liver
The portal triad is composed of a branch of the hepatic artery, portal vein, and bile duct.
Contains the main structures that enter or leave the liver parenchyma
What does each functional segment of the liver possess?
- branch of hepatic artery
- branch of hepatic portal vein (blood from other abdo. organs to the liver)
- bile drainage (to bile duct)
- Venous drainage ( to IVC
What happens to the hepatic veins before they enter the IVC?
The hepatic veins carrying deoxygenated blood from the liver come together as 3 veins before entering the IVC
Which ligament do the structures of the portal triad run within?
Hepatoduodenal Ligament (of lesser omentum)
Portal triad contains hepatic portal vein, hepatic artery proper, bile duct.
Distinguishing features of Coeliac Trunk:
1st of 3 midline branches of the abdominal aorta
Leave aorta at T12 vertebral level
What area does the Coeliac Trunk supply?
The coeliac trunk trifurcates into which 3 branches?
Left gastric artery
Common hepatic artery
What organs do the branches of the coeliac trunk supply?
Splenic - spleen
Left gastric - lesser curvature of stomach (+ lower oesophagus)
Common hepatic - liver, pylorus of the stomach, duodenum and pancreas
Superior Pancreaticoduodenal Artery:
The superior pancreaticoduodenal artery is an artery that supplies blood to the duodenum and pancreas.
It is a branch of the gastroduodenal artery (supplies pylorus and + proximal duodenum, branch of common hepatic)
What is the surface anatomy of the spleen?
- located within left hypochondrium
- Protected by ribs 9-11
The spleen is a retroperitoneal organ
The spleen is intraperitoneal
What is the major blood supply of the lesser curvature of the stomach?
Right (from hepatic artery proper) and Left (coeliac trunk branch) gastric arteries
They anastamose together
What is the major blood supply of the greater curvature of the stomach?
Right (from gastro-duodenal artery) and Left (from splenic proper) Gastro-omental arteries
They anastamose together
What is the minor blood supply to the stomach?
Posterior gastric arteries (from splenic artery)
Short gastric arteries (from splenic artery)
Where does blood supply to the liver come from?
R + L Hepatic arteries
Branches of hepatic artery proper
> only accounts for 20-25% of blood received by the liver
(75-80% from hepatic portal vein)
Explain the structure of a liver lobule
Lobule has a central vein in the middle and an interlobular portal triad at each corner
(Interlobular portal triad = branch of HPV, branch of HA, biliary duct)
The sinusoids are lined by hepatocytes and the central vein collects 'cleaned' blood and drains into hepatic veins
What are the two clinically important areas of the peritoneal cavity related to the liver?
Hepatorenal Recess (Morison's Pouch)
> both are within the greater sac
Why is the Hepatorenal Recess relevant for bedridden patients?
The recess is one of the lowest parts of the peritoneal cavities when the patient is supine and pus from an abscess in the sub-phrenic recess can drain into the recess in bedridden patients
Hepatic Portal Vein:
Drains blood from foregut, midgut and hindgut to the liver for first pass metabolism (cleaning)
What veins make up the hepatic portal vein?
- Splenic vein (foregut)
- Superior mesenteric vein (midgut)
- Inferior mesenteric vein (hindgut > drains into splenic vein)
- IVC (drains cleaned blood from HPV into RA)
Name the portal triad structures in order from anterior to posterior
Hepatic artery proper
Hepatic portal vein
Where does the gallbladder lie?
Lies on the posterior aspect of the liver, anterior to the duodenum
What is the function of the gallbladder?
Stores and concentrates bile in between meals (sphincters prevent bile passage so it builds until sphincters are released)
Where does the gallbladder drain via?
Bile flows in and out via the Cystic Duct
(Joins with the common hepatic duct to form the bile duct)
What artery supplies the cystic duct and where is it located?
Located in the Cystohepatic Triangle (of Calot)
Explain the pain presentation of gallbladder inflammation (or cystic duct, e.g. gallstone)
- Gallbladder is a foregut organ with visceral afferents that enter spinal cord between T6-T9
- Early pain in epigastric region
- Later pain in hypochondrium (possibly with right shoulder pain due to anterior diaphragmatic irritation)
Surgical removal of the gallbladder
Refers to the liver, gall bladder and bile ducts, and how they work together to make, store and secrete bile
What does bile consist of?
Bile consists of water, electrolytes, bile acids, cholesterol, phospholipids and conjugated bilirubin.
Explain the different ducts that combine to form the Bile Duct
- Right and left hepatic ducts unite to form Common Hepatic Duct
- Common hepatic duct units with Cystic Duct to form Bile Duct (Common Bile Duct)
Where does the Bile Duct drain to?
The bile duct joins the main pancreati duct and drains into the 2nd part of the duodenum
Name the 4 parts of the duodenum and whether they are intra- or retro-peritoneal
- Superior (part intraperitoneal) + Duodenal Cap (mobile)
- Descending (retro)
- Horizontal (retro)
- Ascending (retro)
anatomical sphincter controlling the flow of chyme from stomach to duodenum
Made of smooth muscle innervated by parasym. + sym. nerves
Border between the duodenum and the jejunum (marks end of duodenum)
Where does duodenal pain usually present?
What peptide hormones does the duodenum secrete into the blood?
The Pancreas is a retroperitoneal organ
Name the sections of the pancreas
Head (with uncinate process)
Describe the location of the pancreas
Lies transversely across the posterior abdomen and head of pancreas is surrounded by C-shape of duodenum
What is the function of the pancreas?
Exocrine: Acinar cells secrete pancreatic digestive enzymes into main pancreatic duct
Endocrine: Islets of Langerhans release insulin & glucagon into bloodstream
Major Duodenal Papilla:
The major duodenal papilla is an opening of the Common bile duct and Pancreatic duct into the duodenum (ampulla of vater)
Hepatopancreatic Ampulla (of Vater):
Union of pancreatic duct and common bile duct before it drains into the duodenum.
Located at the major duodenal papilla
What are the relevant sphincters of the biliary system?
Bile duct sphincter
Pancreatic duct sphincter
Sphincter of Oddi
What is ERCP (Endoscopic Retrograde Cholangiopancreatography) and how is it done?
Investigation used to study the biliary tree and pancreas (and to treat some pathologies assoc. with it)
Endoscope passed from oral cavity to duodenum and cannula placed in major papilla > radio-opaque dye injected back into biliary tree
How can gallstones or carcinomas at the head of the pancreas result in jaundice?
Results in a flow of bile backup to the liver
There is overspill into the blood, of its constituents (e.g. bilirubin) = extra hepatic (outisde liver) obstructive cause of jaundice/post-hepatic jaundice
Which 3 main arteries supply the pancreas?
- Superior Pancreaticoduodenal artery (from gastroduodenal) and Inferior Pancreaticoduodenal artery (from SMA) > anastamosis
Pancreatic branches of Splenic artery (from coeliac trunk)
Give an example of one cause of Pancreatitis
Blockage of the ampulla by a gallstone
Leads to bile being diverted into pancreas leading to irritation and inflammation
Where does pancreatic pain usually present?
Pancreas is a foregut and a midgut organ so...
Pain can present in epigastric AND/OR umbilical region
(Can also radiate through to patients back)
What 2 signs of vascular haemorrhage can indicate a more advanced case of pancreatitis?
Grey-Turner's Sign - bruising on right or left flank
Cullen's Sign - bruising around umbilicus via falciform ligament
Vascular haemorrhage leads to blood/fluid accumulating in the retroperitoneal space
The small intestine is a midgut organ
The 1st and 2nd parts of the duodenum are FOREGUT organs
The rest of the small intestines are midgut
Name the 3 parts of the small intestine
Point where the duodenum ends and the jejunum starts
Where the ileum ends and the separation between the ileum and the large intestine
Explain the differences between the Jejunum and Ileum in regards to the following:
Colour: jejunum deep red, ileum lighter pink
Wall: jejunum thicker+heavy, ileum thinner+lighter
Vascularity: jejunum more vascular than ileum
Mesenteric: ileum has more mesenteric fat than jejunum
Folds: jejunum has large, tall+closely packed folds > ileum has low+sparse folds
Lymphoid Tissue: only present in tissue (Peyer's Patches)
What is the arterial supply for the jejunum and ileum?
Superior Mesenteric Artery
via jejunal and ileal arteries
What's the path of the venous drainage from the jejunum and ileum?
- From the jejunal and ileal veins
- To superior mesenteric vein
- To hepatic portal vein
The vessels of the jejunum and ileum travel within the _____________
What else is absorbed into the portal venous system from the small intestine as well as blood?
Proteins and carbohydrates
What is the path of the superior mesenteric vessels?
- Leaves aorta at L1 vertebral level
- Posterior to neck of pancreas
- Travels inferiorly, anterior to the uncinate process of pancreas
- Enters the mesentery proper
Describe the absorption of fat from the intestines
- Bile helps in fat absorption from the lumen into intestinal cells
- Fats (within chylomicrons) are absorbed from intestinal cells into specialised lymphatic vessels of small intestine (LACTEALS)
- Travel via the lymphatic system to eventually drain into venous system (at left venous angle)
e.g. superior mesenteric lymph nodes to thoracic duct
What are the main groups of lymph nodes draining abdominal organs?
Foregut - Celiac nodes
Midgut - Superior Mesenteric nodes
Hindgut - Inferior mesenteric nodes
Kidneys, posterior abdo. wall, pelvis + lower limbs - Lumbar
Which two lymph vessels do all superficial lymph vessels drain into?
Thoracic Duct (3/4 of body)
Right Lymphatic Duct (1/4 of body)