1
Q
Appendix: Gross anatomy
A
- Arises approximately 2-3cm inferior to the ilioceacal valve, at the convergence of the teni coli.
- Variable length 2-20cm
- Has a mesentery – mesoappendix
- Variable position of the tip: retrocaecal, pelvic, pre or post-ileal
2
Q
Appendix: Neurovasculature
A
- Arterial: Appendicular artery a branch of the ilicolic artery
- Venous: Similar named veins draining into the portal system
- Lymphatics: Superior mesenteric group
- Innervation: Superior mesenteric
3
Q
Appendix: Relations
A
- Anterior: Parietal peritoneum, loops of small bowel
- Posterior: Iliacus and psoas muscles, femoral nerve
- Medial: Terminal ilium
- Lateral: iliacus and psoas muscles
- Superior: ileocecal valve
- Inferior: lateral third of the inguinal ligament
4
Q
Appendix: Variants
A
- Position
- retrocecal (65-70%)
- pelvic (25-30%)
- pre- or post-ileal (5%)
- promontory
- paracaecal
- subcecal
- Variants
- additional arterial supply from accessory appendicular artery
- duplex appendix: very rare
- agenesis of the appendix
5
Q
Biliary Tree: Description:
A
The biliary tree is the system of biliary vessels of the liver and abdomen
Location:
Intrahepatic and within the free edge of the lesser omentum
6
Q
Biliary tree: Gross Anatomy
A
Dividable into intrahepatic and extrahepatic ducts
Each liver segment has its own biliary drainage duct, where biliary canaliculi unite to form segmental ducts. There ducts join to form:
- Right posterior duct
- Right anterior duct
- Right hepatic duct
- Left hepatic duct
7
Q
Biliary Tree: Course
A
The right and left hepatic duct unite to form the common hepatic duct, segment I drains directly here also. The common hepatic duct then leaves the liver parenchyma.
The common hepatic duct is joint by the cystic duct of the gallbladder arfter ~2-3cm, they unite to form the common bile duct.
The common bile duct runs in the free edge of the lesser omentum, behind the head of the pancreas to join with the main pancreatic duct forming the ampulla of Vater draining into the D2 via the sphincter of oddi.
8
Q
Biliary Tree: Neurovasculature
A
Blood supply:
- Right and left hepatic artery
- Cystic artery
- Branches of the common hepatic artery
- Posterior pancreaticoduodenal artery branches
- Gastroduodenal artery
Venous:
- Into the portal system
Lymphatics:
- Porta hepatis nodes
- Coeliac nodes
Innervation:
- Coeliac plexus
9
Q
Biliary Tree: Relations
A
At the porta hepatis:
The common hepatic duct lies in front and is to the right of the hepatic artery, the portal vein is between the two
10
Q
Biliary Tree: Variants
A
Cystic duct:
- Duplication
- Low insertion
- High insertion
- Cystic artery posterior to the right hepatic duct
Common hepatic duct:
- Triple confluence
- Aberrant hepatic duct
- Non-union of the left and right hepatic ducts
CBD:
- May pass behind through or around the pancreatic head
- Variable location of the ampulla
- CBD may drain separately from the main pancreatic duct
- Pancreatic divisum
11
Q
Extrahepatic Biliary Tree: Description
A
The extra hepatic biliary tree is the system responsible for the drainage and storage of bile from the liver to the D2 segment of the duodenum.
12
Q
Extrahepatic biliary tree: Gross Anatomy
A
The left and right intrahepatic ducts join to form the common hepatic duct which leaves the liver parenchyma at the porta hepatis anterior to the hepatic artery and to the right of the portal vein.
The common hepatic duct joins the cystic duct to form the common bile duct.
The common bile duct initially travels in the free edge of the lesser omentum, then courses posterior to the duodenum and the pancreas joining the main pancreatic duct to form the ampulla of Vater.
The ampulla of Vater drains into D2 via the major duodenal papillae
13
Q
Extrahepatic Biliary Tree: Neurovasculature
A
Arteries:
- Cystic
- Right hepatic
- Posterior superior pancreaticoduodenal artery
Venous:
- Drains to portal vein
Lymphatics:
- Porta hepatis
- Coeliac
14
Q
Extrahepatic Biliary Tree: Variants
A
Cystic duct:
- Low insertion
- Medial insertion
- Parallel course
- Cystic artery anterior to the cystic duct
Common hepatic duct:
- Triple confluence
- Aberrant hepatic duct
- Non-union of the right and left hepatic ducts
Common bile duct:
- Partially covered posteriorly
- Completely covered
- Completely uncovered
- Lateral to pancreatic head
15
Q
Caecum: Description
A
- The caecum is the first section of the large bowel
- Location: typically located in the right iliac fossa, considered and intraabdominal segment of large bowel
- Function: Receive the contents of the small bowel, dilates to accommodate this contents and gas production
16
Q
Caecum: Gross Anatomy
A
- Sac like structure
- Diameter typically from 3-9cm
- Covered in visceral peritoneum typically has a short mesentery
- 3 teni coli
- Haustral folds of the bowel wall between the teni
- Vermiform appendix has its origin at the base of the ceacum
- Fat containing ileocecal valve (one was between the ilium and the caecum)
17
Q
Caecum Neurovasculature
A
Arterial supply:
- Anterior and posterior caecal arteries from the colic artery from the ileocolic trunk of the superior mesenteric artery
Venous drainage:
- Anterior and posterior caecal veins into the portal system via the superior mesenteric vein
Innervation:
- Superior mesenteric plexus and vagal trunks
Lymphatics:
- Local mesenteric nodes
- Superior mesenteric nodes
18
Q
Caecum: Relations
A
- Posterior: iliacus muscle, psoas muscle, femoral nerve, lateral femoral cutaneous nerve
- Anterior: anterior abdominal wall, parietal peritoneum
- Lateral: iliacus
- Medial: terminal ilium
- Inferior: appendix, lateral third of the inguinal ligament
- Superior: large bowel continues as the ascending colon
19
Q
Caecum: Variants
A
- May be on a long mesentery
- Absence of a mesentery
- Location anywhere in the intraabdominal cavity
20
Q
Duodenum: Description
A
- The duodenum is the first part of the small intestine
- Location: between the pylorus of the stomach and the jejunum, in the anterior pararenal space
- Function: Alkalinisation of chym, mixing of bile with chyme, sensing of chyme to produce gastrointestinal reflexes
21
Q
Duodenum: Gross Anatomy
A
- D1 (5 cm)
- commences at the pylorus and passes backward, upward, and to the right, beneath the quadrate lobe to the body of the gall-bladder
- intraperitoneal for first 2-3 cm
- D2 (7.5 cm)
- descends along the right margin of the head of the pancreas, generally to the level of the upper border of the body of L3
- pancreatic duct and CBD enter the descending duodenum through the major duodenal papilla (ampulla of Vater)
- also contains the minor duodenal papilla, the entrance for the accessory pancreatic duct
- junction between the embryological foregut and midgut lies just below the major duodenal papilla
- D3 (10 cm)
- takes a second bend, and passes from right to left across the vertebral column
- D4 (2.5 cm)
- ascends and ends opposite L2
- unites with the jejunum, forming the duodendojejunal flexure
- DJ flexure is surrounded by a peritoneal fold containing muscle fibres (ligament of Treitz)
22
Q
Duodenal Segments
A
- D1 from the pylorus of the stomach courses to the right, features duodenum bulb
- D2 from the D1 segment descending approximately 3-4cm, features major and minor duodenal papilla
- D3 from D2 turn to the left around the pancreatic head course
- D4 from D3 continues to course to the left however also ascends to the ligament of Treitz, after the small bowel continues as the jejunum
23
Q
Duodenal Relations
A
- D1
- anteriorly - gallbladder, quadrate lobe of liver
- posteriorly - common bile duct, portal vein, gastroduodenal artery
- superiorly - epiploic foramen
- inferiorly - pancreatic head
- D2
- anteriorly - transverse mesocolon
- posteriorly - right kidney, right ureter, right adrenal gland
- superiorly - liver, gallbladder (variable)
- inferiorly - loops of jejunum
- laterally - ascending colon, hepatic flexure, right kidney
- medially - pancreatic head
- D3
- anteriorly - small bowel mesentery root, SMA, SMV
- posteriorly - right psoas muscle, right crus of diaphragm, right ureter, gonadal vessels, aorta and IVC
- superiorly - pancreatic head / uncinate process
- inferiorly - loops of jejunum
- D4
- superiorly - stomach
- inferiorly - loops of jejunum
- posteriorly - left psoas muscle, aorta, left renal vessels
24
Q
Duodenum: Neurovasculature
A
Arterial supply:
- Duodenal cap (first 2.5cm) - supraduodenal artery (branch of gastroduodenal artery)
- Remaining D1 to mid D2 - superior pancreaticodudenal artery (branch of gastroduodenal artery)
- Mid-D2 to ligament of Trietz - inferior pancreaticoduodenal arteries (branch of SMA)
Venous drainage:
- Duodenal cap (first 2.5cm) - prepyloric vein (drains to portal vein)
- Remaining duodenum - superior pancreaticoduodenal vein (drains to portal vein) and inferior pancreaticoduodenal vein (drains to SMV)
Lymph drainage:
- Coeliac Nodes
- Superior Mesenteric Nodes
Nerve supply:
- Sympathetic nerve fibres via coelic and superior mesenteric trunks
- Parasympathetic nerve fibres via anterior and posterior vagal trunks
- Enteric nervous system
25
Duodenal variants
* Duodenal diverticulum - most commonly occurs in D2 or D3
* Duodenal duplication - most commonly occurs at the medial wall of D2 or D3
* appears as a cystic structure that does not communicate with the lumen
* Malrotation
* Duodenal atresia
* Third part can cross as low as L4
26
Jejunum: Description
The Jejunum is the proximal 2/5 of the small intestine
27
Jejunum: Gross Anatomy
* Approximately 3m in length
* More valvuae conniventes than the ileum
* Normal wall thickness 3mm
* The ileum has a smaller diameter 2.5cm vs 3cm jejunum
28
Jejunum: Relations
The jejunum lies in the free edge of the mesentery
29
Jejunum Neurovasculature
Arterial supply:
* Jejunal branches from the superior mesenteric artery
Venous:
* Jejunal veins draining into the SMV--\>; portal
Lymphatic drainage:
* Superior mesenteric nodes
Innervation:
* Superior mesenteric plexus (vagus)
30
Ileum
The ileum is the final part of the small intestine
Gross anatomy:
* 2-4m in length
* Separated from the caecum by the ileocaecal value
* Relations etc at the same as for the jejunum
31
Differences between the jejunum and ileum:
Location:
* jejunum: upper left part of the peritoneal cavity
* ileum: lower right part of the peritoneal cavity
Gross appearance:
* jejunum: greater calibre (3 cm), thicker walls and more vascular
* ileum: lesser calibre (2 cm), thinner walls and less vascular
interior:
* jejunal folds (valvulae conniventes) are thicker (2-3 mm) than ileal folds (1-2 mm)
* jejunal folds are also more numerous and deeper than ileal folds
Mesentery:
* jejunum: less fat, longer vasa recta, fewer arterial arcades
* ileum: more fat, more arterial arcades, shorter vasa recta
Immunology:
* presence of aggregated lymphoid follicles (Peyer patches), more prominent in the ileum
32
Gall Bladder Description:
The gallbladder is a pear shaped musculomembranous sac that is part of the extrahepatic biliary system.
* Location: Within the gallbladder fossa
* Function: The storage and concentration of bile
33
Gallbladder Gross Anatomy
Gross anatomy:
* Typically 7 to 10 cm in length and 2.5 cm wide. Holding about 30ml of bile.
* Drains bile via the cystic duct, which joins the common hepatic duct to form the common bile duct
* The gallbladder is attached to the gallbladder fossa by connective tissues and vessels
* The under surface of the gallbladder is covered by peritoneum
Dividable into:
* Fundus
* Body
* Neck
Layers:
* Serosa
* Muscularis externa
* Lamina Propria
* Mucosa
34
Gallbladder: Relations
* Superior: Visceral surface of the liver
* Inferiorly: D2 segment of the duodenum
* Anteriorly: 9 th costal cartilage
* Posteriorly: Right kidney, distal D1
* Medial: D1, free margin of the lesser omentum and the epiploic foramen
* Laterally: the right lobe of the liver
35
Gallbladder: Neurovasculature
Blood supply:
* Cystic artery from the right hepatic artery
* Direct venous drainage into the liver
Innervation:
* Sympathetic: coeliac plexus
* Parasympathetic: via the anterior vagal trunk
Lymphatics:
* Drains into the portal nodes then to the coeliac nodes
36
Gallbladder: Variants
* Morphology
* Phrygian cap: the fundus is sometimes folded back upon itself
* Hartmann pouch (infundibulum): neck is focally dilated and probably pathological / related to cholelithiasis
* Number
* accessory gallbladder
* gallbladder bifid / duplication / triplication
* cystic duct may also be duplicated / tripled
* gallbladder agenesis
* Location
* left-lobe \> intrahepatic \> retrohepatic
* Cystic duct
* low cystic duct insertion - into the distal-third of the CHD
* medial cystic duct insertion - into the left, not the right, side of the CHD
* parallel cystic duct course - courses parallel to the CHD for at least 2cm
* cystic duct empties into the right posterior hepatic duct
37
Left kidney: Description
The kidneys are paired retropenritoneal organs. Function: production of urine, water and electrolyte homeostatsis, hormone production Location: Perirenal space, long axis parallel to psoas, lies on quadratus lumborum
38
Left Kidney: Gross Anatomy
* 9-14cm long, left usually larger than the right
* Bean shaped
* Fibrous capsule
* Divided in the superior, mid and inferior poles
* The parenchyma consists of cortex and medulla.
* The renal sinus consists of the renal pelvis, calyces, vessels, nerves, lymphatics and fat
* The renal cortex lie peripheral
* The medulla consists of 10-14 hilum facing pyramids, separated by renal columns
* Each pyramid drains into minor calyces via a papilla, which inturn 3-4 join to form the major calyces, of which 2-3 join to drain into the renal pelvis
39
Left kidney: Neurovasculature
* Arterial: right and left renal arteries from the abdominal aorta level L1
* Venous: Right and left renal veins into the inferior vena cava
* Innervation: Renal plexus
* Lymphatics: Peri-renal and para-aortic
40
Right Kidney: Relations
* Anterior: Hepatic flexure, liver
* Posterior: Diaphragm, quadratus lumborium
* Superior: right adrenal gland, liver
* Inferior: Right ureter
* Medial: duodenum, inferior vena cava
41
Left Kidney: Relations
* Anterior: Splenic flexure, stomach, lesser sac
* Posterior: quadratus lumborum
* Superior: Spleen
* Inferior: Left ureter
* Medially: Jejunum and pancreas
42
Kidney: Variants
Horseshoe, agenesis, cross fused renal ectopia, pancake, pelvic kidney, colomn of bertin, dromedary hump, accessory renal arteries, duplex collecting system, retrocaval ureter
43
Ureters: Description
The ureters are paired fibro-muscular tubes between the kidneys and urinary bladder.
Function: transport of urine
Location: Proximally in the pararenal space of the retroperitoneum
44
Ureters: Gross Anatomy
Gross anatomy:
Length: ~25cm in adults, 3mm in diameter
Divided into three parts:
* Abdominal ureter
* Pelvis ureter
* Intravesicular ureter
45
Ureters: Course
* Runs along the medial aspect of the psoas major
* ureter lies anteriorly and slightly medial to the tips of the L2-L5 transverse processes
* Enters the pelvis anteriorly to the sacroiliac joint at the bifurcation of the common iliac vessels (at the pelvic brim) and then courses anteriorly to the internal iliac artery down the lateral pelvic sidewall
* At the level of the ischial spine it turns forward and medially to enter the posterolateral wall of the bladder
* then runs an oblique 1-2cm course before opening into the bladder at the internal ureteric orifice
* in the male
* ureter crosses above the seminal vesicles and is crossed by the ductus deferens
* in the female
* ureter runs medial and forward on the lateral aspect of the cervix and upper part of the vagina to reach the fundus of the bladder
* here it is crossed by the uterine artery
* Constrictions of the ureter are the most common sites of stone obstruction
* pelvi-ureteric junction (PUJ)
* as the ureter enters the pelvis and crosses over the common iliac artery bifurcation
* vesicoureteric junction (VUJ)
46
Ureters: Relations
* Abdominal ureter
* posteriorly
* psoas muscle, genitofemoral nerve, common iliac vessels, tips of L2-L5 transverse processes
* anteriorly
* right ureter: descending duodenum (D2), gonadal vessels, right colic vessels, ileocolic vessels
* left ureter: gonadal artery, left colic artery, loops of jejunum, sigmoid mesentery and colon
* medially
* right ureter: IVC
* left ureter: abdominal aorta
* Pelvic ureter
* posteriorly
* sacroiliac joint, internal iliac artery
* inferiorly
* male: seminal vesicle
* female: lateral fornix of the vagina
* anteriorly
* male: ductus deferens
* female: uterine artery (in the broad ligament)
* medially
* female: cervix
47
Ureters: Neurovasculature
Arterial:
* Renal arteries
* Direct branches from the aorta
* Superior and inferior vesicular arteries
Venous:
Same veins – highly variable
Lymphatics:
Para-aortic
Internal and external iliac
Innervation: renal plexus and hypogastric plexus
48
Ureters: Variants
* Duplex collecting system
* bifid ureter
* ectopic insertion
* ureterocoele
49
Pancreas:Description
The pancreas is a mixed endocrine/exocrine organ of the gastrointestinal system
Location: anterior pararenal space
Function: Production of digestive fluid, control of metabolism
50
Pancreas: Gross Anatomy
Linear organ
Divided into:
* Head – thickest part, attached to the c loop of the duodenum, uncinated process extends posteriorly
* Neck – Thinnest part, lies anterior to the SMA and SMV, portal confluence
* Body - main part lies to the left of the SMA, SMV
* Tail – lies within the layers of the splenorenal ligament
Pancreatic secretions are drained by a system of pancreatic ducts that converge on the main pancreatic duct in the majority of individuals. This joins with the common bile duct forming the ampulla of Vater which typically drains into the 2 nd part of the duodenum by the sphincter of oddi.
51
Pancreas: Neurovasculature
Arterial supply:
* Branches from the Splenic Artery
* Superior Pancreaticoduodenal Artery (Gastroduodenal Artery)
* Inferior Pancreaticoduodenal Artery (SMA)
Venous drainage:
* Drains to the SMV and splenic veins and ultimately portal vein
Lymphatic drainage:
* Coeliac / Superior Mesenteric Nodes
Nerve supply:
* Spinal Cord Segment T6 to T10
* Vagal Trunks
52
Pancreas: Relations
* Head/Uncinate process
* Lodged within the curve of the duodenum
* Posterior: aorta, IVC, CBD, right renal vessels, right crus of the diaphragm, SMA, SMV
* uncinate process passes posterior to the SMV and SMA
* Anterior: small bowel
* Neck
* Antero-superiorly: pylorus
* Posterior: commencement of the portal vein
* Body
* Anterior: lesser sac
* Posterior: splenic vein, left kidney, left renal vessels, left suprarenal gland
* Superior: splenic artery
* Tail
* Extends to the splenic hilum
* Lies within the lienorenal ligament
53
Pancreas: Variants
Pancreas Divisum: MPD drains at minor duodenal papilla (incomplete: communication with duct of Wirsung vs complete: no communication with duct of Wirsung)
Annular Pancreas: ventral pancreatic bud fails to rotate resulting in ring of pancreatic tissue around second part of duodenum
Agenesis of Dorsal Pancreas: failure of the dorsal pancreatic bud to form the body and tail of the pancreas
Ectopic Pancreas: gastric antrum, proximal duodenum, ileum, Meckel's diverticulum
Bifid tail of pancreas / fishtail pancreas: rare branching anomaly of pancreatic tail and duct system
54
Pancreatic Duct: Gross Anatomy
Main pancreatic duct (Wirsung) – runs the length of the pancreas terminates at the ampulla of Vater, formed by the fusion of the dorsal and ventral ducts.
Accessory pancreatic duct (Santorini) – Variant, usually connects to the main duct, runs in the head of the pancreas drains to the minor duodenal papilla. Ruminant of the dorsal duct.
Smaller ducts – clusters of exocrine pancreastic cells for acini which are connected to:
intercalated ducts
Intralobular ducts join to the main pancreatic duct in a herringbone pattern
55
Pancreatic Duct Variants
* Pancreatic divisum – most common variant, failure of fusion of the dorsal and ventral ducts. As a result the majority of pancreastic secretions are drained via the minor papilla, believed to increase the risk of pancreatitis. Types;
* 1 no connection
* 2 Absent ventral duct
* 3 Inadequate connection
* Santorrinicele – cystic dilation of the of the dorsal duct in the setting of pancreatic divisum
* Meandering main pancreatic duct – maybe z-type or loop type
* Ansa pancreatica – loop like connection between the main and accessory ducts
* Anomalous pancreaticobiliary junction – union of the pancreatic duct and the common bile duct outside of the duodenal wall
56
Right Adrenal Gland: Description
Paired retroperitoneal endocrine organs
Function: Production of multiple hormones
Location: Enclosed within the pararenal fascia superior to each kidney
57
Right adrenal gland: Gross Anatomy
Right pyramid shaped, left spoon shaped
Body with a medial and lateral limbs
Outer cortex and inner medulla
Cortex has 3 zones:
* Glomerulosa
* Fasciculata
* Reticularis
58
Right adrenal gland: Relations
* Superior – Right crus
* Inferior – upper pole of the right kidney
* Lateral – right lobe of the liver
* Medial – right crus
* Anterior – inferior vena cava
* Posterior – upper pole of the right kidney
59
Left adrenal glands: Relations
* Superior – left crus
* Inferior – upper ple of the left kidney
* Lateral – spleen
* Medial – left crus
* Anterior – pancreas
* Posterior – upper pole of the left kidney
60
Right Adrenal Gland: Neurovasculature
Arterial supply:
* Superior adrenal artery - Branch of the Inferior Phrenic Artery
* Middle adrenal artery - Branch of Abdominal Aorta
* Inferior adrenal artery - Branch of Renal artery
Venous drainage:
* Mainly by single adrenal vein
* Left adrenal vein drains into the left renal vein
* Right adrenal vein drains into the IVC
Lymphatic drainage:
* Para-aortic Lymph Nodes
Nerve supply:
* Splanchnic nerves from the Coeliac and Renal Plexuses
61
Right adrenal gland variants
* Horseshoe adrenal gland: solitary adrenal gland that is present in the midline
* Pancake adrenal gland: takes on a flattened appearance, often in the presence of a pelvic kidney or renal agenesis
* Adrenal gland hypoplasia/agenesis
* Accessory adrenal glands: often near adrenal glands but may be found anywhere in the abdomen, pelvis or scrotum
62
Segmental Anatomy of the liver: Descriptions
The liver can be divided into 8 functionally independent segments using the Couinaud classification
system.
63
Segmental anatomy of the liver: Gross anatomy
Each segment has its own dual blood inflow, lymphatic and biliary drainage
Each segment is a wedge pointed at the porta hepatis
The segement are divided in to a superior and inferior group by a horizontal plane drawn at the level of the bifurcation of the portal vein.
The segments are divided right to left by vertical planes following the hepatic veins.
64
Segments of the liver
Segment 1 – caudate lobe special in this system as is can receive supply from the left and right portal system, location – around the vena cava, divided into medial caudate process and lateral papillary process. Drains directly into the IVC
Segment 2 and 3 – to the left of the left hepatic vein, superior and inferior to the portal vein bifurcation
Segement 4 – between the left and middle hepatic veins, divided into A for part above the bifurcation of the portal vein and B for below
5 and 6 – Both inferior to the portal bifurcation, 5 between the middle and the right hepatic veins, 6 to the right of the right hepatic vein
7 and 8 - both above the portal vein bifurcation, 7 to the right of the right hepatic vein, 8 between
the right and middle hepatic veins
65
Segmental anatomy of the liver: Variants
* Right or left supply to the caudate
* Hepatic vein duplication
* Reidels lobe
* Beavertail liver
66
Liver: Description
Large metabolic organ in the right upper quadrant of the abdomen
Function:
* Detoxification
* Glycogen storage
* Hormone production
* Production of plasma proteins
* Storage of vitamins
67
Liver Gross Anatomy
* Wedge shaped organ that lies below the right hemidiaphragm
* Dividable into four lobes based on surface anatomy
* Right lobe, left lobe, caudate lobe and quadrate lobe
* Dividable into 8 independently resectable segments
* Two surfaces diaphragmatic and visceral
* Predominantly covered with peritoneum bar a bare area on the superior aspect
* Capsule called Glisson’s capsule
68
Liver: Ligaments
* Falciform ligament / ligamentum terres / ligamentum venosum
* Lesser omentum
* Coronary ligaments left and right
* Triangular ligaments
69
Liver:Relations
* Superior – right hemidiaphragm
* Inferior – Gallbladder/portahepatis/right adrenal gland and kidney/hepatic flexure
* Medial – duodenum
70
Liver: Neurovasculature
Arterial supply:
* Hepatic artery
Venous:
* Hepatic veins draining into the IVC
Special circulation:
* Portal vein
Lymphatics:
* Portahepatis to coeliac nodes
* Superior surface can drain to mediastinum
Nerves:
* Coeliac plexus T7-T9 (Sympathetic) and vagal trucks (parasympathetic ) phrenic contribution to bare area
71
Liver: Variants
Variation:
* Riedels lobe – extension on the segment five inferiorly
* Beaver tail liver – left lobe extends around to the spleen
* Agenesis of the right or left lobe
72
Spleen: Description
The spleen is an unpaired haematological organ of the abdomen
Function: Immune, red cell production and maturation
Location: left hypochondrium
73
Spleen: Gross Anatomy
* Wedge shaped
* ~12.5cm in length
* Enclosed by a thin capsule
* Tissues consists of inner red pulp and outer white pulp
* Has a upper and lower pole
* Has a visceral and diaphragmatic surface
* Covered by peritoneum except the hilum which has the:
* Gastrosplenic ligament
* Splenorenal ligament
74
Spleen: Neurovasculature
Arterial supply:
* Splenic artery
* at the splenic hilum the splenic artery divides into superior and inferior terminal branches
* each terminal branch further dividing into four-to-six intrasplenic segmental branches
Venous drainage:
* Splenic vein
Lymphatic drainage:
* Lymph drains into several nodes lying at the splenic hilum and subsequently to the coeliac nodes
Nerve supply:
* Sympathetic only: coeliac plexus
75
Spleen: Relations
Superior: under surface of the diaphragm
Medial: posterior wall of the stomach, tail of the pancreas
Inferior: left colic flexure
Posterior: anterior surface of the left kidney and suprarenal gland
76
Spleen: Variants
* 10% accessory spleen
* Wandering spleen
* Polysplenia
* Aspenia
* Splenogonal fusion
* Retrorenal spleen
77
Stomach: Description
Muscular organ between the oesophagus and duodenum.
Location: upper abdomen
Function: storage and digestion of food
78
Stomach: Gross Anatomy
* Divided into:
* Cardia – receives the oesophagus
* Fundus – superolateral dome
* Body – main region
* Pyloris – lower section exit point
79
Stomach: Muscles
* Lower oesophageal sphincter
* Pylorus
80
Stomach: Neurovasculature
Arterial supply:
* Right gastric common hepatic
* Left gastric from the coeliac trunk
* Right gastroepiploic from the superior gastroduodenal
* Left gastroepiploic from the splenic
* Short gastric from splenic and terminal left gastroepiploic
Venous drainage:
* Right and left gastric veins to the portal vein
* Right gastroepiploic to the superior mesenteric vein
* Left gastroepiploic veins and short veins to the splenic
Lymphatics:
* Coeliac and para-aortic nodes
Innervation:
* Gastric plexus (coeliac and vagus)
81
Stomach: Relations
* Anterior: left lobe of the liver, anterior abdominal wall
* Posterior: lesser sac and stomach bed
* Medial: abdominal aorta, coeliac trunk and nodes
82
Stomach: Variants
* Situs inversus
* Hypertonic or hypotonic stomach
* Pyloric stenosis
* Congenital hiatus hernia
83
Anterior Abdominal wall: Description
The anterior abdominal wall is the anterior musculofasical structure that forms the anterior limit of the intraabdominal space.
Function: Anterior boundary of the abdominal cavity, flexion of the trunk
Location: between the pubis symphysis and iliac crests inferiorly and the xiphoid process and costal cartilages superiorly laterally end with the muscular bodies of the obliques
84
Anterior Abdominal Wall: Layers
* Skin
* Subcutaneous fat
* Camper’s fasica
* Scarpa’s Fascia
* Abdominal wall muscles
* Transversalis fascia
* Extra-peritoneal fat
* Parietal peritoneum
85
Anterior Abdominal Wall: Muscles
* Rectus abdominus
* Internal oblique
* External oblique
* Transversus abdominus
86
Anterior Abdominal Wall: Features
* Linea alba
* Linea semilunaris
* Arcute line – IO spits above and goes Transversalis fascia passes the rectus anterior below the line
87
Anterior abdominal Wall: Neurovasculature
Arterial supply:
* Superior and inferior epigastric arteries
* Subcostal arteries
* Superficial epigastric arteries
* Superficial circumflex iliac
* Superficial external pudendal
Venous drainage:
* Above the umbilicus – drain to azygos system
* Below the umbilicus – drains to the femoral system via the great saphenous vein
Innervation:
* Subcostal, iliohypogastric and ilioinguinal nerves T7 to L1
Lymphatics:
* Above umbilicus: Axially
* Below the umbilicus: superficial inguinal nodes
88
Anterior abdominal wall: Variants
Pyramidalis, patent uracus, congenital hernia
89
Rectus Abdominis and Sheath: Description
The rectus abdominis muscle is a strap-like muscle that forms part of the anterior abdominal wall.
Function: flexion of the trunk, aid in the containment of the abdominal contents
90
Rectus Abdominis and Sheath: Gross Anatomy
Has three to four horizontal tendinous intersections that divide the muscle into segments.
Origin: Pubic symphysis, tubercle and crest
Insertion: Xiphisternum and the 5-7 th costal cartilages
91
Rectus Abdominis and Sheath: Features
* The linear alba divides the recti into right and left
* Laterally the rectus sheath fuses to form the linea semilunaris
* Above the arcute line the IO splits to form the rectus sheath
* Below the arcute line the transversalis fascia passes anterior to the rectus abdominus
92
Rectus Abdominis and Sheath: Neurovasculature
Arterial supply:
* Superior and inferior epigastric arties
Venous drainage:
* Superior and inferior epigastric veins
Innervation:
* Anterior rami of T6 to L1 spinal nerve
Lymphatics:
* Above the umbilicus to the axillary nodes
* Below the umbilicus to the inguinal nodes
93
Rectus Abdominis and Sheath: Relations
* Anterior: Rectus sheath, Camper’s fascia, Scarper’s fascia
* Posterior: pre-peritoneal fat, peritoneum
* Lateral: hiatus semilunaris
* Medial: Linea alba
* Superior: xiphoid process and the 5th to 8th costal cartilages
* Inferior: Pubic symphysis
94
Rectus Abdominis and Sheath: Variants
Variation in the number of segments
Pyramidalis
95
Aorta: Description
* The abdominal aorta is the main arterial supply trunk from the abdomen, pelvis and lower limbs.
* Function: deliver oxygenated blood
* Location: great vessel space of the retroperitoneum
96
Aorta: Gross anatomy
* Origin: continuation of the thoracic aorta and the aortic hiatus T12
* Course: descends anterior and slightly to the left of the vertebral bodies
* Termination: Bifurcates at the level L4
97
Aorta: Paired Branches
* Inferior phrenic
* Middle adrenal
* Renal arteries (~L1)
* Gonadal arteries (~L2)
* Lumbar arteriesx4
98
Aorta: Unpaired Branches
* Coeliac trunk (T12)
* Superior mesenteric (L1)
* Inferior mesenteric (L3)
* Median sacral
99
Aorta: Relations
* Posterior to the median arcuate ligament
* Anterior and to the left of the vertebral bodies
* IVC is on the right
* Crossed anteriorly by the splenic vein and the body of the pancreas between the coeliac and superior mesenteric artery groups
100
Aorta: Variants
* Variable level of bifurcation
* Right sided aorta
* Coeliacomesenteric trunk
* Sinuous course
* Accessory renal artery
* Direct branches
101
Arterial supply and venous drainage of the kidneys: Description
The kidneys are retroperitoneal organs involved in the filtration of blood, production of urine, water
and electrolyte balance and the production of hormones
102
Arterial supply of the kidneys: Origin
Typically a single renal artery from the aorta at the level L1 inferior to the origin of the superior mesenteric artery, however there are commonly additional accessory arteries.
103
Arterial Supply of the kidneys: Course
the right renal artery passes posterior to the IVC and the right renal vein, the left renal artery courses posterior to the left renal vein
104
Arterial Supply of the Kidneys: Branches
* Dorsal and ventral rami
* The dorsal and ventral rami divide into segmental branches within the renal hilum these branches are:
* Apical
* Anterior superior
* Posterior superior
* Inferior
* Posterior
* These segmental branches divide to form the:
* Arcute
* Interlobar
* Interlobular
* Inferior adrenal artery
* Ureteric artery
* Capsular artery
105
Venous Drainage of the Kidneys
Asymmetric paired veins that drain deoxygenated blood from the kidneys
106
Venous Drainage of Kidneys: Origin
Formed by the union of 2-3 parenchymal veins at the renal hilum
107
Venous Drainage of the Kidneys: Course
emerges from the renal hilum anterior to the renal arteries
Termination: drains into the inferior vena cava at this level L2
Tributaries:
Left renal vein: left gonadal, left inferior phrenic vein, left adrenal vein, capsular branches
Right: Capsular branches
108
Venous Drainage of the kidneys:Variants
* Accessory renal arteries occur in 30% of the population
* Aberrant renal artery, enters the capsule instead of the hilum
* Prehilar branching occurs in 10% of the population (important for renal transplant)
* Pre-aortic or Circumaortic left renal veins
109
Superior Mesenteric Artery: Description
The superior mesenteric artery carries oxygenated blood to the midgut. It is one of three unpaired arteries of the abdominal aorta.
110
Superior Mesenteric Artery: Gross Anatomy
Origin:
* Arising anteriorly from abdominal aorta at the level of L1
Course/Relations:
* Courses anteroinferiorly
* Behind the neck of pancreas and splenic vein
* Crossing anterior to the left renal vein
* Emerges anterior to the uncinate process of the pancreas
* Crosses anterior to D3
* Superior mesenteric vein (SMV) should always lie to the right of the SMA
* otherwise malrotation should be suspected
* Enters the upper portion of the small bowel mesentery and runs along the root of the mesentery downwards to the right
* Other relations: anterior to right ureter, origin is inferior to coeliac trunk
Termination:
* SMA terminates at the ileum where it anastomoses with the ileal branch of the ileocolic artery
111
Superior Mesenteric Artery: Branches
* Inferior pancreaticoduodenal artery
* anastomoses with the superior pancreaticoduodenal artery and supplies the head of the pancreas, D2 and D3
* Jejunal branches
* Ileal branches
* Ileocolic artery
* ileal branch, colic branch, anterior and posterior caecal branches, appendicular branch
* Right colic artery
* ascending and descending branches
* Middle colic artery
* left and right branches
* Terminal branches of the ileocolic, right colic and middle colic arteries - along with the terminal branches of the left colic artery and sigmoid branches of the IMA - form a continuous arterial arcade along the inner border of the colon known as the marginal artery of Drummond with straight arteries known as vasa recta
* Jejunal and ileal branches also form a series of anastomosing arcades from which vasa recta arise
112
Superior Mesenteric Artery: Supplies
* D2 onwards
* Head of pancreas
* Jejunum
* Ileum
* Caecum
* Ascending colon
* Right 2/3 of the transverse colon
113
Superior Mesenteric Artery: Variant Anatomy
* SMA may arise from the aorta as two trunks
* SMA sometimes arises from, or has common trunk with, the coeliac trunk
* May give rise to branches usually derived from other sources:
* right hepatic
* accessory right hepatic
* gastroduodenal
* IMA
* left colic
* Arc of Riolan
114
Inferior Mesenteric Artery: Description
The inferior mesenteric artery is the primary arterial supply for the hindgut
115
Inferior Mesenteric Artery: Gross Anatomy
Origin:
* Arising from abdominal aorta at the level of L3
* Close to the lower border of D3
Course/Relations:
* Artery descends anteriorly to the aorta
* Then passes to the left as it continues inferiorly
* Crosses the left common iliac artery and continues into the pelvis as the superior rectal artery
Termination:
* Terminates as the superior rectal artery
116
Inferior Mesenteric Artery: Branches
* Left colic
* Two to four sigmoid arteris
* Superior rectal artery
117
Inferior Mesenteric Artery: Supplies
Bowel from the splenic flexure to the upper 2/3 of the rectum
118
Inferior Mesenteric Artery: Relations
* Anterior: D3
* Posterior: abdominal aorta, left psoas, left common iliac artery
* Lateral (left): Inferior mesenteric vein
119
Inferior Mesenteric Arteries: Variants
* Doubled IMA
* Absent IMA
* Common trunks
* Absent left colic branch
* Arc of Riolan (SMA/IMA connection)
120
Arterial Supply of the liver:
The liver is supplied by both an arterial system and the portal venous system
121
Common hepatic Artery
* Origin: branch of the coeliac axis
* Course: runs in the free edge of the lesser omentum
* Termination: bifurcates into the proper hepatic and gastroduodenal arteries
* Branches:
* Proper hepatic artery
* Gastroduodenal artery
* Right gastric artery
122
Proper Hepatic Artery
* Origin: from the common hepatic artery in the free edge of the lesser omentum
* Course: continues in the free edge toward the porta hepatis, runs to the right and anterior to the portal vein
* Termination: bifurcates to form the right and left hepatic arteries
* Branches:
* Right (cystic artery) and left hepatic arteries
123
Right Hepatic Artery
* Origin: bifurcation of the proper hepatic artery at the porta hepatis
* Course: enters the porta, crosses behind the common hepatic duct to enter Calots triangle.
* Termination:
* Segmental branches within the liver
* Branches:
* Cystic artery
* Segmental arteries
124
Left Hepatic Artery
* Origin: bifurcation of the properhepatic artery
* Course: toward the umbilical fissure
* Branches:
* Segmental branches
125
Arterial Supply of the liver: variants
* Seen in 40 – 45% of people
* Michel classification:
* 1 – standard anatomy
* 2 – replaced LHA
* 3 – replaced RHA
* 4 – replaced both
* 5 – accessory LHA
* 6-8 – Accessory RHA from variable origins
* 9 – Common hepatic replaced by the SMA
* 10 – Common hepatic replaced by the LGA
126
Coeliac Trunk
Also known as the coeliac axis is the primary abdominal arterial supply to the foregut.
Location: first unpaired branch of the abdominal aorta (T12)
127
Coeliac Trunk: Gross Anatomy
* Origin: anterior branch of the abdominal aorta at the level of T12, just under to the medial arcuate ligament
* Course: Very short course before under the median arcuate ligament
* Termination: trifurcation into its three branches:
* Common hepatic – (right gastric, properhepatic, gastroduedenal)
* Splenic
* Left gastric arteries
128
Coeliac Trunk: Supplies
* Gut from the distal oesophagus to the D2
* Liver
* Gallbladder
* Spleen
* Pancreas
129
Coeliac Trunk: Variants
* Classical branching is seen in 70%
* Branches may arise independently from the aorta
* Coeliacomesenteric trunk
* Other branches may arise from the trunk including:
* Dorsal pancreatic artery
* Right hepatic artery
* Inferior phrenic artery
130
Foetal Circulation: Description
* The fetal circulation differs from the non-fetal circulation due to the presents of certain vessels and shunts that close shortly after birth.
* The role of the shunts is to ensure oxygen-rich blood bypasses the underdeveloped pulmonary circulation.
131
Foetal Circulation: Shunts
* Ductus venosus – fetal liver shunts oxygen and nutrient rich blood from the umblical vein to the inferior vena cava
* Foramen ovale – Shunts blood from the right atrium to the left atrium bypassing the pulmonary vasculature
* Ductus arteriosis – Shunts blood from the left pulmonary artery to the aorta also bypassing the pulmonary circulation
132
Foetal Circulation: Oxygenated Blood pathway
* Placental villi remove oxygen and nutrients from the maternal circulation which subsequently transit through the umbilical vein, within the umbilical cord.
* The umbilical vein bifurcates after entering the umbilicus:
* Right branch – passes to the right of the liver and joins the portal vein
* Left branch – joins the ductus venosus (under pressure due to narrow DV)
133
Foetal Circulation: de-oxygenated Blood pathway
Mixes at the heart largely bypasses the pulmonary circulation due to the shunts, enters the umbilical arteries (anterior division of the internal iliac vessels), they enter the umbilical cord and it is relayed back to the placenta
134
Foetal Circulation: Variants
* 2 vessel cord – one artery and one vein
* Patent FO
* Patent DA
135
IVC: Description
* The inferior vena cava is the primary blood return pathway from the abdomen and lower limbs back to the heart
* Function: return of de-oxygenated blood from the abdomen and lower limb to the heart
* Location: Retroperitoneum and short course in the posterior mediastinum
136
IVC: Gross Anatomy
* Has valves
* Origin: Formed as the confluence of the common iliac veins at the level L5
* Course: Ascending in the great vessel space, passes through the posterior aspect of the liver, through the caval hiatus of the diaphragm at the level T8 short course in the posterior mediastinum
* Termination: right atrium
137
IVC: Tributaries
* Common iliac veins (L5)
* Lumbar veins (L1-L5)
* Right gonadal veins L2
* Bilateral renal veins L1
* Right adrenal veins L1
* Right and left inferior phrenic veins T8
* Right, middle and left hepatic veins T8
138
IVC: Relations
* Anterior: Right common iliac artery, right gonadal vessels, D3, common bile duct, portal vein, head of the pancreas, D1, epiploic foramen, liver
* Posterior: Lower lumbar vertebrae and discs, anterior longitudinal ligament, Right psoas belly, sympathetic trunk
* Lateral left: abdominal aorta, caudate lobe of the liver, right crus
* Lateral right: right kidney, right ureter, D2
139
IVC: Variants
* Duplication
* Agenesis
* Circumcaval ureter
* Circumaortic vena cava
* High union
* Double inferior vena cava
* Left sided vena cava
* IVC webs
* Portocaval shunt
140
Superior Mesenteric Vein: Gross Anatomy
Origin/Course:
* Mesenteric venous arcades (which accompany the arteries) unite to form the jejunal and ileal veins in the small bowel mesentery
* Ascends between the two layers of the mesentery on the right side of the superior mesenteric artery
* if it is not in this position, it can indicate intestinal malrotation
* SMV is considered the common trunk after all the chief tributaries have joined
* Gastrocolic trunk drains into the right-hand aspect of the SMV just anterior to the uncinate process of the pancreas
* Unites with the splenic vein posterior the neck of the pancreas (at the level of L1) to form the portal vein
141
Superior Mesenteric Vein: tributaries
* Jejunal and ilial veins
* Ilicolic vein
* Right colic vein
* Inferior pancreaticoduodenal vein
* Gastrocolic trunk:
* Right gastroepiploic
* Middle colic
* Anterior superior pancreaticoduodenal
142
Splenic Vein
* Drains the pancreas, spleen, part of the stomach and hindgut
* Origin: Splenic hilum
* Course: emerges from the splenorenal ligament, courses behind the pancreas in close relation with the splenic artery
* Termination: joins SMV to become portal vein
143
Splenic Vein: Tributaries
* Short gastric veins
* Left gastroepiploic
* Inferior mesenteric
* Pancreatic
144
Portal Vein: Gross Anatomy
* Origin: L1 confluence of the splenic and superior mesenteric veins
* Course: runs in the free edge of the lesser omentum enter the porta hepatic as a posterior structure
* Termination: bifurcated to form right and left braches, the level of bifurcation in used to define the boundaries of the liver segments
145
Portal Vein: Variants
* Portal trifurcation
* Absent right portal vein
* Portal vein duplication
* Left renal veins drains into the portal system
* Absent SMV, all branches converge to for the portal vein
* Abernathy malformation portosystemic shunt
146
Lumbar Plexus: Description
The lumbar plexus is a complex nerve plexus formed from nerve roots (T12 to L5) which supplies
motor and sensory to the lower limb
147
Lumbar Plexus: Gross Anatomy
Origin: Ventral rami (T12 to L5)
Course: Formed within the psoas muscle, anterior to the lumbar transverse processes
148
Lumbar Plexus: Branches
(Subcostal T12)
Iliohypogastric (L1)
Ilioinguinal (L1)
Genitofemoral (L1 and L2)
Lateral femoral cutaneous nerve (L2 and L3)
Obturator nerve (L2, L3 and L4)
Femoral nerve (L2, L3 and L4)
Lumbosacral trunk (L4 and L5)
149
Lumbar Plexus: Relations
* Lateral to psoas:
* Iliohypogastric
* Ilioinguinal
* Lateral femoral cutaneous
* Medial to psoas:
* Obturator and lumbosacral trunk
* Anterior to psoas:
* Genitofemoral
150
Lumbar Plexus: Variants
Variants:
* Absent iliohypogastric nerve
* Early branching
* Accessory obturator
151
Cisterna Chyli
Is a saccular dilation of the lymphatic channels located in the retrocrural space
152
Cisterna Chyli: Gross anatomy
* Location: to the right of the abdominal aorta at the level L1
* Origin: confluence of multiple abdominal lymphatic trunks
* Termination: Continues of the thoracic duct
* Drainage: Structures below the diaphragm
153
Cisterna Chyli: Relations
* Anterior: Right crus of the diaphragm
* Posterior: L1 and L2 vertebral bodies
* Left: Abdominal aorta
* Right: Azygos vein
154
Lymph Node Groups of the Abdomen
* Para-aortic lymph
* Pre-aortic
* Portal and portal caval nodes
* Gastric node stations
* Peripancreatic nodes
* Common iliac nodes
* Internal and external node groups
155
Epiploic Foramen: Description
The epiploic foramen aka foramen of Winslow is a passage between the greater and lesser sac allowing communication between these two spaces
156
Epiploic Foramen: Borders
Anterior: the free border of the lesser omentum (hepatoduodenal ligament)
this has two layers and within these layers are the CBD, proper hepatic artery and portal vein (DAVE: Duct, Artery, Vein, Epiploic foramen)
hepatoduodenal ligament + hepatogastric ligament = lesser omentum
Posterior: the peritoneum covering the inferior vena cava
Superior: the peritoneum covering the caudate lobe of the liver
Inferior: the peritoneum covering the commencement of the duodenum and the hepatic artery
hepatic artery passes forward below the foramen before ascending between the two layers of the hepatoduodenal ligament
Left lateral: gastrosplenic ligament and splenorenal ligament
157
Structures at L1
* Pancreas
* Transverse mesocolon
* Abdominal aorta
* Origin of the SMA and SMV
* Inferior vena cava
* D2
* Liver
* Hilum of the kidneys
* Hilum of the spleen
* Lesser sack
* Stomach
* Epiploic foramen
* Liver
158
Retroperitoneal Spaces: Description
The retroperitoneum is a space in the abdominal cavity
Location: between the posterior parietal peritoneum and the muscle of the back
159
Retroperitoneal Spaces: Gross Anatomy
Dividable into 4 spaces by the pararenal fascia
* Anterior pararenal space –anterior to the kidneys, extends from the diaphragm to the pelvis
* Perirenal space – around the kidney, from the bare area of the liver and subphrenic space, continuous with the mediastinum through the diaphragmatic hiatuses, inferiorly it is closed below the kidneys
* Posterior pararenal space – posterior to the kidneys, extends from the inferior phrenic fascia opens into the pelvis
* Great vessel space - the space around the abdominal aorta and inferior vena cava, only named in some sources
160
Anterior Pararenal Space: Contents
Duodenum, pancreas, ascending and descending colon, roots of the small bowel mesentery and transverse mesocolon.
161
Perirenal Space: Contents
kidneys, adrenal glands, the proximal collecting system, perirenal fat, renal vessels
162
Posterior pararenal space: contents
small space containing olny fat, lymphatics, blood vessels, no major organs
163
Great Vessel Space: Contents
Abdominal aorta and inferior vena cava
164
Anterior Perirenal Fascia
thinner of the two courses from the lateral origin at the lateral
parietal peritoneum to cross anterior to the great vessels of the abdomen. Also known as Gerota’s fascia.
165
Posterior Perirenal Fascia
thicker of the two origin is the psoas fascia coursing laterally to
become the laterconal fascia continuing on as the lateral parietal peritoneum. Also known as Zuckerkandl’s fascia.
166
Peritoneum: Description
* Serous membrane which forms a closed sac within the abdominal cavity
* Function:
* To protect and allow the movement of some abdominal organs
* reflections form ligaments for the structural support of the organs
* Reflections make passages for the transmission of neurovasculature
167
Peritoneum: Supramesocolic spaces
* Right side:
* Right subphrenic space
* Right subhepatic space (including Morison’s pouch)
* Lesser sac (extends to the left but is only in communication with right via the foramen of Winslow)
* Left side:
* Left subhepatic space
* Left Subphrenic space
168
Peritoneum: Inframesocolic spaces
Right and left paracolic gutters
Right and left inframesocolic spaces
169
Peritoneum: Innfervation
* Parietal peritoneum – by the same nerves as the muscle it overlies
* Visceral perioneum – no afferent supply
* Diaphragmatic – by the Phrenic nerve C345
170
Peritoneal Ligaments
* Triangular ligaments
* Falciform ligaments
* Lesser omentum
* Gastrosplenic ligament
* Splenorenal ligament
171
Portal Vein Tributaries
* Splenic vein
* SMV
* Cystic vein (to right branch of portal vein)
* Paraumbilical veins (left branch of portal vein)
* Left and right gastric veins
* Superior pancreatico-duodenal vein
* Supraduodenal veins
172
Portocaval anastamoses
Region
Name of clinical condition
Portal circulation
Systemic circulation
Esophageal
Esophageal varices
Esophageal branch of left gastric vein
Esophageal branches of azygos vein
Rectal
Rectal varices
Superior rectal vein
Middle rectal veins and inferior rectal veins
Paraumbilical
Caput medusae
Paraumbilical veins (becomes ligamentum teres of the liver)
Superficial epigastric vein
Retroperitoneal
(no clinical name)
Right colic vein, middle colic vein, left colic vein
Renal vein, suprarenal vein, paravertebral vein, gonadal vein
Intrahepatic
Patent ductus venosus (ligamentum venosum)
Left branch of portal vein
Inferior vena cava
173
Psoas major: Description
* Psoas major muscle is a muscles of the posterior abdominal wall
* Lies in the iliopsoas compartment (posterior to the retroperitoneum)
* Fuses with the iliacus muscle to form the iliopsoas muscle at the level of L5-S2
* Passes deep to the inguinal ligament
* Psoas muscle is enclosed by the psoas fascia, therefore pus is contained in a psoas abscess
174
Psoas muscle: Gross anatomy
Origin:
* Vertebral bodies, intervertebral discs and transverse processes of T12 to L5
Insertion:
* Lesser trochanter of the femur
Action:
* Lateral flexion of the trunk
* Stabiliser and flexor of the hip
175
Psoas Muscle: Relations
* The lumbar plexus is embedded within the muscle and its branch emerge from it:
* anterior aspect: genitofemoral nerve
* lateral border: iliohypogastric, ilioinguinal, lateral femoral cutaneous and femoral nerves
* medial border: obturator nerve and lumbosacral trunk
* Forms floor of the femoral triangle: femoral vein, artery, nerve, lymphatics
176
Psoas: Neurovasculature
Nerve supply:
* L1-L3 roots of the lumbar plexus
Blood supply:
* Lumbar branch of the iliolumbar artery
Variation:
* Asymmetry (no clinical significance)
177
SMV: Variants
* Absence of common draining trunk with two "intestinal trunks" draining directly into the splenic vein (~10%)
* SMV may receive an accessory splenic vein
* May drain into the a renal vein
* Pancreaticoduodenal veins may drain into it directly
* IMV may empty into the SMV
* Ascends on the left of SMA in malrotation
Anatomy
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