Anatomy - Abdomen Flashcards
Boundaries of anterior abdominal wall:
How many layers
Sup: cartilage of 7th-10th ribs and xiphisternum
Inf: inguinal lig and superior margins of pelvic girlde
3 muscultendonous layers containing a total of 4 muscles.
From post to ant what are the muscles of abdo wall?
Describe their course
1) Transversus abdominis: extends medial from thoracolumar fascia to linea alba or ribs sup
2) Int. oblique: Extends superiomedially from thoracolumbar fascia and iliac creast to linea alba and 10th-12th ribs
3) Rectus abdominis: extends superiorly from pubic symph and pubic crest to xiphisternum and 5th-7th ribs
4) External obliques: extend inferiomedialy from 5th-12th ribs to linear alba and anterior half of iliac crest
Arterial supply to the anterior abdominal wall:
○ Internal thoracic artery → superior epigastric artery
○ Aorta → subcostal artery
○ External iliac artery → inferior epigastric artery
○ Femoral artery → superficial epigastric artery
Venous drainage and key clinical anasatamosis of anterior abdominal wall:
○ Superior
■ internal thoracic vein → brachiocephalic vein
■ lateral thoracic vein → axillary vein
○ Inferior
■ superficial epigastric vein → accessory saphenous → great saphenous → femoral vein
■ inferior epigastric vein → external iliac vein
○ Anastomoses
■ between lateral thoracic vein and superficial epigastric vein
● blood from thorax can drain into femoral vein and from lower abdomen can drain to axillary
■ around the umbilicus with para-umbilical veins from the portal system
Lymphatic drainage of the anterior abdominal wall can be divided into:
Superficial and deep:
● Superficial
○ Superior
■ axillary lymph nodes
■ parasternal lymph nodes
○ Inferior
■ superficial inguinal lymph nodes
● Deep
○ Accompany deep veins of the abdominal wall and drain to
■ external iliac, common iliac, para-aortic nodes
The pyloric sphincter is at what verterbral level? It demarcates what?
The pyloric sphincter demarcates the transpyloric plane at the level of L1
The pylorus of the stomach can be divided into?
Antrum, canal, sphincter
Anatomical relations of the stomach:
Superior:
Oesophagus and left dome of the diaphragm
Anterior:
Diaphragm, greater omentum, anterior abdominal wall, left lobe of liver, gall bladder
Posterior:
Lesser sac, pancreas, left kidney, left adrenal gland, spleen, splenic artery, transverse mesocolon
Greater curvature: Arising at the ……. …….., it arches backwards and passes ……… to the …….. It curves to the …… as it continues medially to reach the pyloric antrum.
Greater curvature – forms the long, convex, lateral border of the stomach. Arising at the cardiac notch, it arches backwards and passes inferiorly to the left. It curves to the right as it continues medially to reach the pyloric antrum.
Supply to the greater curvature:
The ….. ….. ….. and the ….. and ….. …..-….. arteries supply branches to the greater curvature of the stomach
The short gastric arteries and the right and left gastro-omental arteries supply branches to the greater curvature.
At what vertebral level is the coeliac trunk? What are the vessels from Left to right?
It arises from the anterior aspect of the aorta, at the aortic hiatus of the diaphragm (T12 level).
Left to right:
left gastric (eosophageal and left gastric branches), splenic and common hepatic arteries.
The Splenic passes under the left gastric to become the left-most vessel, giving off 2 branches to the greater curvature (left gastroepiploeic and short gastric) and pancreas (pancreatic branches)
Branches of the common hepatic artery:
Sole arterial supply to the liver and the only branch of the coeliac artery to pass to the right.
Past the anterior aspect of the duodenum divides into 2 branches:
1) Proper hepatic:
- Right gastric - pylorus and lesser curvature of the stomach
- Right and left hepatic: divide inferior to the porta hepatis
- Cystic
2) Gastroduodenal:
- Right gastroepiploic (terminal branch): large portion of greater curvature of the stomach and greater omentum, which it also supplies. Anastamoses with left gastroepiploeic/omental aa. from splenic
- Superior pancreaticoduodenal: divides into an anterior and posterior branch, which supplies the head of the pancreas.
Innervation of the stomach:
1) Parasympathetic: from the anterior and posterior vagal trunks of vagus
2) Sympathetic: Arises from the T6-T9 spinal cord segments and passes to the coeliac plexus via the greater splanchnic nerve. It also carries some pain transmitting fibres.
Lymphatic drainage of the stomach
Follows arterial supply to the coeliac nodes.
Greater curvature:
short gastric and left gastro-omental -> Spenic -> trunk
(anastamoses w/),
Right gastro-omental -> gastroduodenal -> common hepatic -> Trunk
Lesser curvature: left gastric (superiorly), Right gastric -> common hepatic ->trunk
Pylorus: Right gastro-omental->gastro duodenal -> hepatic -> Trunk
Venous drainage of the stomach:
The veins of the stomach run parallel to the arteries.
Right and left gastric veins drain into the hepatic portal vein.
The short gastric vein, left and right gastro-omental veins ultimately drain into the superior mesenteric vein.
Course of the portal vein:
Formed from confluence of splenic v. and SMV posterior to neck on pancreas (L2), proceeds superiorly and rightward behind 1st part of duodenum, joined by left and right gastric veins and pancreo-dudenal vein.
Entrer free margin of lesser omentum anterior to epiploic foramen (traveling with hepatic artery, the portal vein, the common bile duct) to enter liver at portahepaticus where it then divides into left and right.
The portal vein accounts for what % of the hepatic blood supply?
How much of the 02 supply?
About how long is it?
75%
50% 02
8cm long
Describe the duodenum:
C-shaped hollow viscous, can be divided into 4 parts, parts 2-4 reteroperitoneal. Associated medially w/head/neck pancreas
1st part 1 inch - duodenal cap is above TP plane. connected to the liver by the hepatoduodenal ligament.
2nd Part 2 inches - Descending part from L1-L3, contains papilliary sphincter
3rd Part - Horizontal, across body of L3, IVC and Aorta
4th Part - ascending, up left side of L3-L2
Histological layers of the duodenum
● Mucosa
○ lined with columnar epithelium
○ contains lamina propria and muscularis mucosa
● Submucosa containing blood vessels and lymphatics
● Muscularis propria
● Serosa
○ peritoneal on anterior surface
How does the mucosal lining differ along the GIT from mouth to anus?
Stratified Squamous Epi: Mouth, eosophagus, anus
Simple Columnar: The rest
The duodenum shares its arterial supply with?
The head of pancreas
Superior pancreaticoduodenal artery is a branch of? Supplies what?
Inferior pancreaticoduodenal artery is a branch of?
Supplies what?
○ Superior pancreaticoduodenal artery
■ branch of common hepatic artery
■ supplies up to ampulla of Vater
○ Inferior pancreaticoduodenal artery
■ branch of SMA
■ supplies distal to ampulla of Vater
Venous drainage of the duodenum (and also)?
Also head of panc:
○ Superior pancreaticoduodenal vein drains to portal vein
○ Inferior pancreaticoduodenal vein drains to SMV
Lymphatic drainage of the duodenum?
● Pancreaticoduodenal
● Pyloric
● Superior mesenteric
● Coeliac
Compare Jejunum to ileum:
Jej: Located in upper left quadrant Thick intestinal wall Longer vasa recta (straight arteries) Less arcades (arterial loops) Red in colour
Ileum: Located in lower right quadrant Thin intestinal wall Shorter vasa recta More arcades Pink in colour
Branches of the common hepatic artery:
From trunk, 1st branch is:
1) Gastroduodenal artery:
- Right gastroepiploic
- Superior pancreoduodenal
2) Right gastric
3) L and right common hepatic (cystic artery branches off right)
General description of the pancreas:
● Lobulated, retroperitoneal organ
● Lies transversely across L1 and L2 vertebra
● Posterior to the stomach and between duodenum (right) and spleen (left)
● Has endocrine and exocrine functions
● Divided into uncinate, head, neck, body and tail.
Where lies the head of the pancreas (not specific relations)?
● Right of midline
● Anterior and to the right of the vertebral column
● Within the curve of the duodenum
The IVC travels on what side of the abdomen?
What part of the pancreas lies anterior to it?
To the right.
Passes posterior to the head of pancreas
Relations of the head of pancreas:
○ Superior: ■ first part of duodenum ○ Inferior ■ 3rd part of duodenum ○ Medial ■ neck of pancreas ○ lateral ■ 2nd part of duodenum ■ superior and inferior pancreaticoduodenal arteries ○ Posterior ■ IVC ■ right renal artery and vein ■ left renal vein ○ Anterior ■ Mesentery and small bowel
The neck of pancreas is defined as?
Portion that lies anterior to the portal vein
Relations of the neck of pancreas?
○ Postero-superior ■ portal vein ■ Splenic vein ○ Antero-superior ■ pylorus ○ Anterior ■ gastroduodenal and anterior superior pancreaticoduodenal arteries ○ Postero-inferior ■ superior mesenteric vein ○ Left ■ body ○ Right ■ head
What is “special” (anatomically) about the body of the pancreas?
Longest portion of the gland
● 3 surfaces: anterosuperior, posterior, anteroinferior
● Anterior surfaces covered by peritoneum
● Part of pancreas that crosses the midline
What passes posterior-inferiorly to the neck of pancreas, but anterior to the uncinate?
Sup mesenteric vessels (i.e SMV joins splenic behind the neck), after passing anteriorly
The SMV arises 1cm below? At what vertebral level?
1cm below coeliac trunk, at L1 (a lot of shit happens at L1)
Relations of the body of pancreas:
○ Superior ■ Coeliac trunk ● common hepatic artery runs to the right ● Splenic artery runs to the left ○ Inferior ■ Superior mesenteric artery and vein ■ Inferior mesenteric vein ■ 4th part of duodenum ■ duodenojejunal flexure ■ Uncinate is inferior to proximal part ○ Anterior ■ Peritoneum ■ Stomach ○ Posterior ■ L2 vertebra ■ Aorta!!!!!!!! ■ Superior mesenteric artery ■ left adrenal gland ■ left kidney ■ renal vessels
What is the anatomically exciting feature of the tail of pancreas?
Nothing - get a life.
It is the only part that is intraperitoneal.Though it is inside the splenorenal ligament with the splenic vessels.
Relations of the tail of pancreas:
Left: spleen
Right: body
Post: splenic branches of the splenic artery and splenic vein
Microscopic features of the pancreas:
● Exocrine acinar cells ○ secretes protease, lipase and amylase ● Endocrine islets of Langerhans ○ more numerous in the tail ○ alpha type: insulin ○ beta type: glucagon ○ delta type: somatostatin and gastrin
Superior pancreaticoduodenal artery comes from?
and has what branches
Superior pancreaticoduodenal artery
○ branch of gastroduodenal artery (from common hepatic)
○ anterior and posterior branches
Inferior pancreaticoduodenal artery comes from?
and has what branches
Branch of superior mesenteric artery
○ anterior and posterior branches=
Arterial supply of pancreas?
Sup and inf pancreaticoduodenal arteries
+
Splenic arteries
Venous supply of pancreas:
● Head and neck
○ superior and inferior pancreaticoduodenal veins → portal vein or SMV
● Body and tail
○ small veins that drain into splenic vein
Lymphatic drainage of pancreas:
Follow the arterial supply. Empty into the pancreaticosplenal nodes and the pyloric nodes, which in turn drain into the superior mesenteric and coeliac lymph nodes. ● Head and neck ○ pancreaticoduodenal ○ superior mesenteric ○ hepatic ○ pre-aortic ○ coeliac ● Body and tail ○ pancreaticosplenic nodes
The unpaired branches of the abdominal aorta and their vertebral levels:
1) Coeliac trunk: Left gastric, splenic, common hepatic
@ T12
2) SMA: Inferior pancreoduodenal, middle colic, right colic, jejunal and ileal branches
@T1
3) IMA: Left colic, sigmoid arteries.
@L3
4) Median sacral artery at L5
Arterial supply to large bowel:
Right and middle colic from SMA
Left colic from IMA.
The paired branches of the abdominal aorta and their vertebral levels:
Which are lateral, which posterior?
1) Inferior phrenic (givens of superior adrenals). Exist more posteriorly @T12
2) Middle suprarenal paired lateral, at same level as coeliac trunk. @T12
3) 1st (of four) lumbar artery. At level of SMA, extends posteriorly (each level 1-4 has a pair of lumbar arteries)
4) Renal arteries (the right passes behind the vena cava @ L1 (inferior to SMA)
5) Gonadal arteries. Pass lateral at L2.
The duodenum has the same lymphatic drainage as?
What is it?
Same as head and neck of pancreas:
Splenoduodenal nodes -> Superior mesenteric -> pre aortic ->coeliac.
