Abdominal visceral anatomy Flashcards
What does the foregut consist of?
Oesophagus / Stomach / Proximal duodenum / Liver / Gallbladder / Pancreas
What is the sympathetic supply of the foregut?
Great splanchnic nerve and coeliac ganglion
Where does the midgut extend to?
From Distal duodenum to the proximal 2/3 of transverse colon
What is the sympathetic supply of the midgut?
Lesser splanchnic nerve and superior mesenteric ganglion
What makes up the hindgut?
Distal 1/3 of the transverse colon to the proximal anus
At which vertebral level does the oesophagus start and finish and what is this level also a landmark for?
C6 - landmark for the cricoid cartilage
Oesophagus ends at T11
What is the distance of the gastro-oesophageal junction from the incisors?
~38cm
What are the 3 vertebral levels at which there are constrictions in the oesophagus?
C6 - T4 - T10
How is the oesophagus divided and what are their respective blood supplies?
Divided into 3 segments
- Upper third: Inferior thyroid artery and vein
(deep cervical lymph drainage) - Middle third: Aortic branches and azygos branches (mediastinal lymph drainage)
- Lower third: Left gastric artery and vein (gastric lymph drainage)
What is the drainage course of the azygos vein?
Drains into the left gastric vein which then drains into the portal vein
Which vessel is responsible for haematemesis in a patient with a BG of portal hypertension?
Left gastric vein
Portal hypertension causes increased pressure in the left gastric vein
What is the venous drainage of oesophageal varices?
Drains into the left hemiazygos vein (due to reverse flow)
At which vertebral level does the abdominal aorta start and where does it terminate?
Starts at T12
Ends at L4
What structures lie anteriorly to the abdominal aorta?
- Left renal vein (crosses AA to drain into IVC)
- Inferior mesenteric vein
- 3rd part of the duodenum
- Pancreas
-Peritoneum
What is the course of the IVC in relation to the AA?
Lies laterally to AA initially and then runs posteriorly distally
At which vertebral level does the Inferior phrenic artery arise?
T12
This artery is paired
At what level is the coeliac axis found?
T12
At which vertebral level does the SMA leave the AA?
L1
At what level is the IMA found at?
L3
At which level does the abdominal aorta bifurcate and what does it give rise to?
Bifurcates at L4
Gives rise to Common Iliac artery
What is the course of the Common Iliac artery and what does it divide into?
Runs along the medial border of the Psoas muscle
Divides into the Internal and External Iliac arteries at the Sacro-iliac joint
When does the External iliac artery become the Femoral artery?
Mid inguinal point
What are the 2 branches of the External iliac artery?
- Inferior epigastric artery (medial wall of deep ring)
- Deep circumflex iliac artery
Which levels do the renal arteries arise?
Left - L1
Right - L2
Where does the Internal iliac artery end and what does it divide into?
Ends at the Greater Sciatic Foramen
Divides into Anterior and Posterior terminal divisions
Which vessels make up the anterior division of the internal iliac artery?
- Umbilical artery (becomes medial umbilical fold)
- Obturator artery
- MIDDLE RECTAL ARTERY
- Internal pudendal artery (gives rise to INFERIOR RECTAL ARTERY)
- Inferior vesical artery (only in MEN - supplies seminal vesicals/ prostate/ bladder / vas def)
- Vaginal and uterine arteries
Which 3 vessels arise from the posterior division of the Internal Iliac artery?
- Iliolumbar artery
- Lateral sacral artery
- Superior gluteal artery
At which level does the IVC start and finish?
Starts at L5 (union of common iliac veins behind the Right common iliac artery_
Ends at T8 (piercing central tendon of diaphragm with inferior phrenic vein)
What are the 4 main posterior branches of the Abdominal Aorta?
- Inferior phrenic artery (T12)
- Lumber arteries (L1-L4)
- Middle supra-renal arteries (L1)
- Median sacral artery (L4)
What are the 3 direct branches of the Coaliac axis?
- Common hepatic artery
- Left Gastric artery
- Splenic artery
What are the 2 branches of the Left gastric and which part of the stomach does the left gastric supply?
Splits into Gastric and Oesophageal artery
Left gastric artery supplies Lesser curvature of the stomach (with right gastric but mostly left)
What is the blood supply to the Greater curvature of the stomach?
Left and Right gastroepiploic arteries (mainly right gastroepiploic)
What are the 5 branches of the Splenic artery?
- Posterior gastric
- Left gastroepiploic artery
- Pancreatic artery
- Splenic
- Short gastric
What are the 2 branches of the Common Hepatic artery?
Gastroduodenal artery AND Proper hepatic artery
What are the 2 branches of the Gastroduodenal artery and where does the gastroduodenal artery arise from?
Gastroduodenal artery is a branch of the Common hepatic artery
Branches into Right gastroepiploic artery AND Superior pancreatoduodenal artery
What does the Short Gastric artery supply?
Supplies Fundus of stomach
Short gastric is branch of Splenic artery
What are the branches of the Proper hepatic artery?
- Right gastric artery
- Left hepatic artery
- Right hepatic artery
Where does the Cystic artery arise from?
Right hepatic artery
What is the anterior and posterior relations of the SMA as it arises at L1?
Anteriorly: body of pancreas
Posteriorly: 3rd part of duodenum
Emerges posterior to the body of the pancreas
What part of the gut does the SMA supply?
Supplies from 2nd part of duodenum to the Distal 1/3 of transverse colon
What are the 5 branches of the SMA and what do they supply?
- Inferior Pancreaticoduodenal artery (supplies duodenum + pancreas + anatomosis with superior pancreaticoduodenal artery)
- Jejunal and Ileal branches
- Ileocolic artery (supplies caecum + appendix + base of ascending colon)
- Right colic artery (supplies ascending + proximal transverse)
- Middle colic artery (supplies proximal 2/3 of transverse colon)
Where does the IMA originate and what are the 3 branches it gives off?
Arises at L3
- Left colic artery (supplies distal 1/3 of transverse + left colic flexure + descending colon)
- Sigmoid arteries
- SUPERIOR RECTAL ARTERY (supplies proximal + middle rectum)
What is the blood supply of the lower lumbar vertebra, sacrum and coccyx?
Median sacral artery (L4 - arises posteriorly to AA)
Which vessel is likely to be the culprit if there is a bleeding ulcer in the greater curvature of the stomach?
Right gastropepiploic artery (branch of gastroduodenal artery - branch of common hepatic artery)
Which vessel is responsible for bleeding in the lesser curvature of the stomach?
Left Gastric artery
A bleeding duodenal ulcer is caused by which vessel?
Caused by erosion of gastroduodenal artery
Where does the Right gastroepiploic vein drain into?
Superior Mesenteric Vein (SMV)
Where do the right and left gastric veins drain into?
Directly into Portal Vein
Where does the Left gastroepiploic vein drain into?
Splenic vein
What 3 main ligaments attach to the stomach and what do they tether the stomach to?
- Gastrohepatic ligament (attaches lesser curvature to the Lesser omentum)
- Gastrocolic ligament (attaches greater curvature to Greater omentum)
- Gastrosplenic ligament (will need to be cut to mobile the spleen)
Where is the duodenum in relation to the vertebral bodies and how many parts is the duodenum split into?
Lies anteriorly to L1-L3
Comprised of 4 parts
What is the course of the 1st part of the duodenum and when does is become the 2nd part?
Starts at pylorus and enters upwards, backward and laterally to the right side of the vertebral column to the neck of the gallbladder where it bends downwards (Superior duodenal flexure) to continue into the 2nd part of the duodenum
Which part of the duodenum is the most likely site for duodenal ulcers?
1st part of the duodenum - freely mobile
Bleeding due to erosion of gastroduodenal artery
What is the embryological origin of the 2nd part of the duodenum and what is the clinical significance of it?
- Upper half grows from foregut
- Lower half grows from midgut
2nd part of duodenum receives input from bile and pancreatic ducts
What structures lie posteriorly to the second part of the duodenum?
- Right kidney + renal vessels
- Right psoas major muscle
What is the course of the 3rd part of the duodenum?
Runs horizontally to the LEFT across lower part of L3, crosses anteriorly to IVC and curves upwards to become constant with 4th part of duodenum
What structures lie posterior to the 3rd part of the duodenum?
- Right ureter
- IVC
- AA
- Right gonadal vessels
Superiorly lies the head of the pancreas
Where is the Spinchter of Odii found?
Lies on the posterior medial aspect of the second part of the duodenum (allows for draining of Ampulla of Vater)
What structure fixes the duodenojejunal flexure?
Ligament of Treitz
Crosses anterior to the coeliac trunk. Originates at Right crus of diaphragm
What structures are found in the small bowel mesentery?
Coils of jejunum and ileum // SMA + SMV // Lymphatics
What is the structural difference between the Jejunum and Ileum?
Jejunum has a larger circumference with longer vasa recta and less fatty mesentery
What is a specific physiological feature that differentiates the large bowel from the small bowel?
Large bowel has HAUSTRATIONS due to Taenia coli (longitudinal muscular band)
In which condition would you see loss of haustrations?
UC
Due to fibrosing of large bowel secondary to chronic inflammation
What is the blood supply of the caecum?
Ilieocolic artery (branch of SMA)
What is the mechanism behind the migratory pain from umbilicus to RIF exhibited in acute appendicitis?
When secretions of the appendix cannot escape, the appendix swell and stretches the VISCERAL PERITONEUM which causes pain in the umbilicus region (T10) carried by sympathetic branches from the SUPERIOR MESENTERIC PLEXUS.
Once the inflammation progresses and becomes transmural, the inflammation directly affects the PARIETAL PERITONEUM localising the pain in the RIF over the appendix
What is the surface anatomy of McBurney’s point?
2/3 from navel to Right ASIS
What is the blood supply of the upper rectum?
Superior rectal artery (from IMA)
What is the blood supply of the middle rectum and where does this vessel arise from?
Middle rectal artery (from Internal iliac artery from common Iliac)
What is the blood supply of the lower rectum and where does this vessel arise from?
Inferior rectal artery (from Internal pudendal artery from Internal iliac)
What divides the liver into left and right surgical (functional) lobes?
CANTLIE’S LINE
Passes from gallbladder fossa to the left of IVC
What is the anatomical reason that segments of the liver can be removed separately without compromising the rest of the segments?
Right and Left hepatic veins divide the liver into 4 sectors
The 4 sectors are divided into 8 segments, each with their own arterial, portal and hepatic duct branch
Which 3 ligaments divide the liver into its anatomical left and right lobe?
Falciform ligament - anterior and superior surface
Fissure of Ligamentous teres - inferior surface
Fissure of Ligamentous venosum - posterior surface
What 2 important structures are found in the right lobe of the liver?
Caudate and Quadrate lobe
Where is Caudate lobe found?
Right lobe of the liver, lies between the groove of the IVC and fissure for ligamentous venosum
Which structure forms the roof of the epiploic foramen?
Caudate process
Where does the porta hepatis lie in relation to the Quadrate lobe?
Porta hepatis lies POSTERIOR to the quadrate lobe
To the left: fissure for ligaments Teres
To the right: gallbladder
Which 3 structures in the liver are not covered by peritoneum?
- Fossa for gallbladder
- Groove for IVC
- Porta hepatis
What are the attachments of the Falciform ligament?
Attaches liver to the diaphragm and anterior abdominal wall
What structure attaches the liver to the stomach and 1st inch of the duodenum?
Lesser omentum
What is the purpose of the upper and lower coronary ligaments in relation to the liver?
Attach liver to the diaphragm
(continuous with the right layer of the falciform ligament)
What are the drainage site of the left, middle and right hepatic veins?
Right hepatic - drains into IVC
Middle and Left hepatic - unite first before draining into the IVC
What is the position of the gallbladder in relation to relevant anatomical structures?
Located between Right costal margin (tip of 9th costal cartilage) and Right Linea semilunaris/Lateral rectus sheath
A patient is stabbed at the right 9th costal margin, which organ is likely to be damaged?
Gallbladder
Located between 9th costal margin and linea semilunaris/lateral rectus sheath
What is the arterial supply to the gallbladder and through which anatomical landmark does it pass through?
Cystic artery
Passes through Triangle of Callot’s
What are the boundaries of Callot’s triangle?
Medially: Common hepatic duct
Laterally: Cystic duct
Superiorly: Inferior edge of liver
What are the contents of Callot’s triangle?
Cystic artery
Lymph nodes
What is the sympathetic nerve supply for the gallbladder?
T7-T9
Why does inflammation to the gallbladder cause referred pain to the right tip of the scapula?
Sensory afferents from gallbladder are carried by the Right Phrenic nerve (C3-5)
This has the same segments as the supraclavicular nerves causing the referred pain
What are the boundaries of the epiploic foramen?
Superior: Caudate process of liver
Inferior: 1st part of duodenum
Posterior: IVC
Anterior: Free border of lesser omentum containing portal vein / CBD / Hepatic artery
What is the Pringles manoeuvre?
Used for control of bleeding from cystic artery
Done by placing finger through Epiploic foramen for compression of the cystic artery
What is the surgical anatomy of the spleen?
Odd numbers (1 - 3 - 5 - 7 - 9 - 11)
- Size: 1 x 3 x 5 inches
- Weight: 7 ounces
- Site: opposite 9th - 11th ribs with long axis parallel with 10th rib
What structures make up the porta hepatis and what structure is most posterior?
Portal triad - VAD (from posterior to anterior)
Porta vein - Hepatic artery - Common hepatic duct
What is a common site of injury during an emergency splenectomy and why?
Tail of pancreas
Tail of pancreas + splenic vessels contained in Lieno-renal ligament which attaches to the posterior margin of the hill and tail of pancreas
What are the relations of the splenic vein and artery in relation to the body of the pancreas?
Splenic vein: posterior to body of pancreas
Splenic artery: travels along superior border of pancreas
What are the 2 pulps of the spleen and what do they contain?
White pulp: macrophages
Red pulp: RBCs
What is the clinical significance of the position of the CBD and IVC in relation to the head of the pancreas?
CBD + IVC lie posteriorly
Cancer of head of pancreas can cause infiltration of IVC and aorta and obstructive jaundice via compression of CBD
What lies anteriorly to the neck of the pancreas?
Pylori-duodenal junction
What vessels unite to form the portal vein?
SMV and splenic vein
What separates the body of the pancreas from the stomach?
Lesser sac
Where do pancreatic pseudocysts most commonly occur?
Body of pancreas
Splenic vein thrombosis can be a complication of which abdominal pathology?
Pancreatitis
What is the name of the duct that drains secretions from pancreas into Ampulla of Vater?
Duct of Wirsung
Which arteries supply the pancreas?
- Superior pancreaticoduodenal artery (from gastroduodenal artery)
- Inferior pancreaticoduodenal artery (from SMA)
What is the embryological formation of the kidney?
Fusion of mesonephric and metanephric ducts. Failure to fuse causes PCKD
What structures make up the renal pelvis?
VAP
Renal vein (anterior)
Renal artery (middle)
Pelvis of ureter (posterior)
What is the Nutcracker syndrome?
Aneurysm of the SMA / AA can cause compression of left renal vein
Causes flank pain, haematuria and kidney injury
What is the name of the fascia that envelopes the kidney?
Gerota’s fascia
What lies anteriorly to the right kidney?
2nd part of the duodenum
What are the 2 main zones of the adrenals and what do they secrete?
Cortex (outer): Mineralocorticoids (aldosterone) // Glucocorticoids (cortisol) // Sex hormones (androgens and oestrogen)
Medulla (inner): catecholamines (NA and adrenaline)
What is the blood supply of the adrenal glands?
Superior: Inferior phrenic artery
Middle: AA
Inferior: renal artery
What is the venous drainage of the adrenal glands?
Right suprarenal vein drains into IVC
Left suprarenal vein drains into Left renal vein, which then drains into the IVC
What is the course of the ureter?
Runs retroperitoneal over the transverse processes of L2-L5 before entering the pelvis in front of the bifurcation of the common iliac artery (at sacroiliac joint).
At the ischial spine, curves anteromedially over Levator ani muscle and drains into the postero-superior angle of the base of there bladder.
In males, ureter crosses beneath vas def from lateral to medial. In females, crosses posterior and beneath uterine artery
What are the 3 main sites of constriction of the ureter?
- Pelvic ureteric junction (L2)
- Inlet of pelvis (bifurcation of common iliac - sacroiliac joint)
- Vesicle-ureteric junction (narrowest part at level of ischial spine)
What supplies the upper part of the ureter?
Renal artery