Lecture 44 - Gastrointestinal Tract 2 Flashcards
Which is the largest viscus in the body?
The liver
Where is the liver located?
Mainly Upper right quadrant
What are the main functions of the liver?
Bile production
Metabolism
Filtering of blood
What are the two surfaces of the liver?
Diaphragmatic
Visceral
What are the features of the diaphragmatic surface of the liver?
Smooth
Anterior and superior
What are the features of the visceral surface of the liver?
Concaved - impressions
Posterior and inferior
Where does the liver lie in reference to the peritoneum?
Intraperitoneal
Describe the divisions of the liver
Two structural lobes:
- large right
- small left
Two functional lobes:
- caudate
- quadrate
What divides the two lobes of the liver?
Anterior: Falciform ligament
Posterior: Ligamentum venosum
Which border of the liver is important?
Inferior border
• sharp
• divides diaphragmatic and visceral surfaces
What is the portal triad?
Hepatic artery
Hepartic duct
Portal vein
What does the hepatic artery do?
Brings blood from the heart to the liver
What does the hepatic duct do?
Delivers bile into the common bile duct / gall bladder
What does the portal vein do?
Delivers blood from the other viscera to the liver
What brings blood away from the liver?
Inferior Vena Cava
What enters the liver via the hilum?
Nerves Lymphatics Hepatic artery Hepatic portal vein Hepatic duct
Draw the anterior and posterior aspects of the liver
:-)
What are the two accessory lobes of the liver?
Draw this.
Caudate
Quadrate
See slide 9
What demarcates the two accessory lobes?
Left and right Sagittal fissures
and Porta hepatis
What is another name for the hilum in the liver?
Porta hepatis
Where does the gall bladder lie?
Draw it in situ
Nestled in groove on posterior surface of the right lobe
Describe the passage of bile from the liver to the duodenum.
Made in the liver
Exits liver by hepatic duct, which then becomes the common bile duct
Sphincter of Oddi closed → bile enters gall bladder
Stored and concentrated in the gall bladder
Exits gall bladder by cystic duct
Enters duodenum by major duodenal papilla
What are the regions of the gall bladder?
Fundus
Body
Neck
Cystic duct
Draw an annotated diagram of the gall bladder and associated ducts.
Refer to slide 11
>:(
What pathology is associated with the gall bladder?
Gall stones
Due to over-concentrated bile
Are gall stones painful?
If they remain in the gall bladder, they are silent
If they move and become lodged in the duct, it is very painful
What does a gall stone look like
They are highly variable
Where does the pancreas lie?
Left upper qudrant
Retroperitoneal
Nestled by the duodenum
What are the four parts of the pancreas?
Draw this
Head
Neck
Body
Tail
Slide 13
Which other organs is the pancreas associated with?
2-3 parts of duodenum
Spleen
Anterior left kidney
Describe the exocrine function of the kidney
- Enzymes secreted into main pancreatic duct
- Main pancreatic duct joins with common bile duct
- Hepatopancreatic ampulla
- Major duodenal papilla
Also, some enzymes from the pancreas travel via the accessory pancreatic duct into the duodenum via the minor duodenal papilla
Describe the endocrine function of the pancreas
Secretes enzymes directly into the blood
eg. Insulin
Why is the spleen the colour that it is?
Dark purple, because it is a reservoir for red cells
What are the two surfaces of the spleen?
Diaphragmatic
Visceral
Where is the spleen located?
Left upper quadrant
In front of ribs 9,10,11
Near pancreas and fundus of stomach
Describe the visceral surface of the spleen
Indentations from surrounding viscera
What is the hilum of the spleen?
Blood vessels: arteries and veins
How may the spleen become damaged?
What is the effect of this?
- It is located directly in front of ribs 9,10,11
- It is very soft, and can be lacterated by fractured ribs
Effect:
• Profuse bleeding into the peritoneal cavity
Describe the path of the aorta
Exits from left ventricle
Runs down behind the oesophagus
Branches at L4 into common iliac arteries
What are the sections of the aorta?
(Ascending
Aortic arch)
- Thoracic aorta
- Abdominal aorta
Comes through the diaphragm at T12 → now is abdominal aorta
What is interesting about the abdominal aorta?
Many branches of arteries
Describe the paired branches of the abdominal aorta
Paired branches go to:
• paired organs
• abdominal walls
- Supra-renal → Adrenals
- Renal arteries
- Ovarian (testicular) arteries
- Phrenic arteries
- many Lumbar arteries
Describe the unparied branches of the abdominal aorta
Unpaired branches go to unpaired organs
• Celiac trunk
• Superior mesenteric artery
• Inferior mesenteric artery
Draw the abdominal aorta
Slide 19
What are the three regions of the gut?
Foregut
Lidgut
Hindgut
What does the celiac trunk supply?
Forgut and visceral derivates • stomach • liver • spleen • pancreas • gall bladder • duodenum up to major duodenal papilla
What does the inferior mesenteric artery supply?
Hindgut • 1/3 of transverse colon • descending colon • sigmoid colon • rectum • midway through anal canal
What does the superior mesenteric artery supply?
Midgut • 3 and 4 of duodenum • small intestine • ascending colon • proximal 2/3 of transverse
Not all visceral derivates of the forgut receive their blood through direct branches of the coeliac trunk. Account for this
Intraperitoneal viscera receive their blood supply through their mesentery
How does the superior mesenteric artery deliver blood?
Branches into the mesentery of the small intestine and ascending colon
How does blood from the viscera get back into the heart?
Inferior vena cava
Paired organs & abdominal walls:
• drains directly into IVC
Unpaired organs
• portal system → liver
• then, IVC
Describe the hepatic portal system
- Blood in unparied organs (stomach, spleen, intestines) drains into the portal vein
- Hepatic veins
- IVC
What makes up the left sagittal fissure?
- Ligamentum venosum
* Round ligament
