APC2 Flashcards
What are the boundaries of the abdominopelvic cavity?
Superior: diaphragm
Inferior: pelvic diaphragm
Anterior/lateral: abdominal muscles/bony pelvis
Posterior: vertebral column, bony pelvis, iliopsoas, fascia
- How does peritoneum line the walls of the APC?
2. What exists between the parietal peritoneum and the overlying muscles of the walls?
- Parietal peritoneum lines walls except where it leaves to invest organs. In most regions, parietal peritoneum loosely attached to allow for alteration in size/position of certain organs, and movement of the walls. In some situations, firmly bound to wall.
- Fibro-fatty connective tissue
What is the blood supply, lymphatic drainage and nerve supply of peritoneum?
Visceral peritoneum: same as those of the viscus of which it covers
Parietal: same as those of the associated abdominopelvic wall
Visceral peritoneum innervated by autonomic nerves
Parietal pertioneum = somatic innervation
Therefore stimuli causing pain in GI tract and associated visceral peritoneum not the same as stimuli causing pain in body wall or associated parietal peritoneum
What are examples of retroperitoneal and secondary retroperitoneal?
Retro:
aorta/IVC, kidneys, nerve trunks, lower 2/3rds rectum, iliac arteries
2ndary retro:
pancreas (except tail), ascend/descend colon, duodenum (2nd-4th)
What are examples of intraperitoneal organs?
Tail of pancreas Small intestines Appendix/caecum Liver Stomach Transverse colon Duodenum - 1st part Rectum upper third Spleen Sigmoid colon
What are three peritoneal structures?
1) Mesentery/mesocolon = double layers attaching small intestine (mesentery), transverse colon and sigmoid colon (mesocolon) to PAW
2) Omentum: two double layers originating from ventral and dorsal mesogastria - greater between stomach and PAW (superficial to small intestine), lesser between stomach and PAW
3) Ligaments (or folds): bands of peritoneum which lie between viscera and body wall - no relation to ligaments surrounding joints
What is significant about peritoneal folds?
In some parts of abdomen may form recesses or fossae of the peritoneal cavity e.g. around duodenojejunal flexure and caecum
Fossae of little importance, but it is possible for loop of intestine to get trapped within on - resulting in intestinal obstruction
Do cutting or pressure cause pain in peritoneum?
Parietal sensitive to all types of stimuli - pain from the PP is well localised and it is sensitive to pressure, pain, laceration and temperature
Visceral peritoneum has same nerve supply as the viscera it invests - pain from the VP is poorly localised and only sensitive to stretch and chemical irritation. Pain from the VP is referred to dermatomes which are supplied by the same sensory ganglia and spinal cord segments as the nerve fibres innervating the viscera
Where do the following mesentery lie?
1) Jejunum and ileum
2) Transverse colon (mesocolon)
3) Sigmoid colon (mesocolon)
1) Attached diagonally across PAW from duodenojejunal flexure on left side of body of second vertebra –> right iliac region
2) Attached horizontally across PAW from anterior aspect of right kidney across descending part of duodenum, to pancreas
3) Inverted V shape - apex is near the bifurcation of the left common iliac artery
Why must care be taken when removing sigmoid colon?
Underneath the sigmoid mesocolon: external iliac vessels (apex is near left common iliac division), left piriformis, and left sacral plexus of nerves, left ureter descends into pelvis behind its apex
Sigmoid and superior rectal vessels run between the layers of the sigmoid mesocolon
What is the lesser omentum?
Derived from ventral mesogastrium - lies between visceral surface of liver and lesser curvature of stomach
From oesophageal end where it is reflected to undersurface of diaphragm, to pyloric end where it is attached to duodenum and PAW
Right edge = ‘free edge’ (anterior layer loops back on itself to become posterior layer at 1ST PART DUODENUM), - encloses the 3 structures en route to liver (biliary ducts, hepatic artery, hepatic portal vein)
What is the greater omentum? (course, development)
1) From dorsal mesogastrium (embryological structure connecting caudal foregut to PAW)
2) Connects stomach & PAW, lies in greater sac
- Visceral layers covering anterior & posterior stomach come together at greater curvature, forming 2 descending (anterior) layers of GO
3) At lower free border of GO, 2 layers fold back on themselves & pass superiorly as the ascending (posterior) layer - these 2 layers become continuous with PP on PAW
- During development the 4 layers of GO become fused
Inferior to attachment at PAW =transverse mesocolon attachment (transverse mesocolon and colon lie posterior to GO, during development GO fuses with it (lifting GO also lifts transverse colon)
What does the greater omentum consist of?
Fat (variable amount)
Gastroepiploic vessels which supply the stomach and omentum
Lymphatic vessels
What are possible functions of the greater omentum?
Fat deposition (varying amounts of adipose tissue) Immune contribution (milky spots of macrophage collection) Infection and wound isolation- may physically limit spread of intraperitoneal infection
What is the lesser sac?
Pouch of peritoneal cavity:
Posterior to liver/lesser omentum/stomach
Anterior to structures on the PAW
Lesser and greater sacs together comprise peritoneal cavity
What is the aditus to the lesser sac?
Epiploic foramen
Where lesser sac is continuous with greater sac
Posterior to free margin of lesser omentum
What is the superior boundary of the lesser sac?
Small recess which extends upwards as far as the diaphragm
What is the inferior boundary of the lesser sac?
In embryonic life - extends between descending and ascending layers of the greater omentum
Fusion of these layers during development - lesser sac becomes obliterated to a level just below the greater curvature of the stomach
What is the anterior wall of the lesser sac?
Liver, lesser omentum, posterior wall of stomach and small portion of greater omentum
What is the posterior wall of the lesser sac?
Bounded by part of the posterior abdominal wall & adherent portions of the greater omentum, covering the transverse colon and the transverse mesocolon
What is the right boundary of the lesser sac?
Initial part of right margin of greater omentum and aditus to lesser sac
What is the left boundary of the lesser sac?
Intitial part of left margin of greater omentum
Lienorenal and gastrosplenic ligaments
What are the boundaries of the epiploic foramen?
Anteriorly: peritoneum forming the free margin of the lesser omentum (note free border = hepatoduodenal ligament)
Superior boundary = caudate lobe (free margin is reflected on to caudate lobe of liver)
Posterior boundary = peritoneum of PAW over IVC (continuous with the peritoneum)
Inferior boundary = peritoneum covering upper border of first part of duodenum
What are the structures in the lesser omentum?
Hepatic portal vein posteriorly
Bile duct anteriorly (to right)
Hepatic artery proper anteriorly (to left)
What is the Pringle manoeuvre?
surgical manoeuvre in some abdominal operations
Large atraumatic haemostat used to clamp hepatoduodenal ligament (free border of lesser omentum), interrupting the flow of blood through the hepatic artery and the portal vein and thus helping to control bleeding from the liver.
More commonly, in the absence of soft clamp, manual compression is performed.
What is the pancreas?
Soft, lobulated organ, approx 15cm long, lies slightly obliquely on PAW
Entirely retroperitoneal
Produces exocrine secretions involved in digestion and endocrine secretions concerned mainly with carbohydrate metabolism
What are the parts of the pancreas?
Head, with uncinate process, neck, body, tail
What is the head of the pancreas?
Broadest part lies within C shape of duodenum
Immediately posterior = vena cava, renal veins and bile duct (bile duct often embedded in pancreatic tissue)
What is the uncinate process?
Projecting from lower part of head, extending to left and posterior to superior mesenteric vessels
What is the neck of the pancreas?
Continuous with head
Anterior to superior mesenteric and hepatic portal veins
(Superior mesenteric vein travels anterior to uncinate process and posterior to neck)
What is the body of the pancreas? (contact with?)
Continues from the neck of the pancreas and gradually slopes superiorly and left
Posterior surface in contact with:
aorta between origins of coeliac and superior mesenteric arteries
left suprarenal gland
left kidney with associated vessels
Splenic vein lies posterior, sometimes embedded within gland itself
Splenic artery lies along upper border
What is the blood supply of the pancreas?
Superior pancreaticoduodenal artery (from gastroduodenal artery supplies head of pancreas and duodenum)
Inferior pancreaticoduodenal artery from superior mesenteric??
What is the best way to identify parts of the pancreas?
Superior mesenteric artery and vein - run anterior to 3rd part of duodenum
Uncinate process is posterior to them
Neck of pancreas anterior to them
Tail of pancreas in contact with spleen
Which parts of the pancreas have peritoneum attached to them?
??
What is significant about the attachment of the transverse mesocolon to the pancreas?
Greater and lesser sacs
Lesser sac above transverse mesocolon/pancreas attachment
Greater sac below (And extends around to much further above)
How does the pancreas appear histologically?
Mostly exocrine, endocrine regions are clusters of pale staining cells
Gland comprised of lobules - separated by connective tissue septa
Staining of pancreatic exocrine cells not uniform - some cytoplasm eosinophilic and some basophilic
Zymogen granules located in exocrine cells (acidophilc) - basal cytoplasm is basophilic
Paccinian corpuscles - transmit pain caused be pressure (pancreatitis)
What is the pancreatic duct?
Main duct of pancreas begins in tail and runs length of gland, receiving pancreatic secretions from most of the gland via numerous tributaries
Pierces the posteromedial wall of duodenum, midway along descending (second) part - joined by bile duct at this point to form HEPATOPANCREATIC AMPULLA
From here, opens into duodenal lumen via MAJOR DUONDENAL PAPILLA
Hepatopancreatic ampulla is surrounded by circular smooth muscle fibres to consitite sphincter of hepatopancreatic ambulla
Sometimes ACCESSORY PANCREATIC DUCT enters duodenum PROXIMAL to main duct
What is the blood supply and lymphatic drainage of the pancreas?
Like duodenum
Coeliac and superior mesenteric provide arterial blood via SPLENIC, GASTRODUODENAL and SUPERIOR AND INFERIOR PANCREATICODUODENAL arteries
Superior mesenteric vein, splenic vein, or directly to hepatic portal vein
Most of the lymph drains to the PANCREATICOSPLENIC nodes
Some passes to nodes along pancreaticoduodenal artery and then SUPERIOR MESENTERIC group of pre-aortic lymph nodes
Surface anatomy of pancreas?
NECK lies on TRANSPYLORIC plane (approx 1cm from midline, behind the pylorus)
BODY extends from neck along line drawn superiorly and left for approximately 10cm to reach hilum of spleen
HEAD lies inferiorly and to right of neck, confined within loop of duodenum
How can the liver be divided physiologically? (functionally)
Two lobes of approximately equal size - marked by sagittal plane passing through GALL BLADDER BED and IVC
Each functional lobe supplied by the right or left branches of the hepatic artery and hepatic portal vein, and drained by right or left hepatic duct
What is the epithelium of the gall bladder? Function?
Simple columnar (of mucosa covering inner surface)
Has microvilli (look like absorptive intestinal cells) - absorptive cells concentrate the bile
What is the course/path of bile?
Formed in liver, collects in BILE CANALICULI
Small ducts unite -> larger ducts –> left or right HEPATIC DUCT in the PORTA HEPATIS
Both receive bile from each physiological lobe of liver –> both converge to form COMMON HEPATIC DUCT
CYSTIC duct connects common hepatic duct to gall bladder - collected and stored here
Gall bladdier empties by contracting walls –> back along cystic duct –> BILE DUCT –> duodenum
What is the gall bladder?
Pear shaped sac - blue during life but stained green in dissections due to leakage of bile content
Held in contact with inferior (visceral) surface of liver by peritoneum, through sometimes suspended by short fold of peritoneum
Posteriorly related to first part of duodenum and
Fundus forms enlarged rounded end, which projects beneath inferior margin on liver - surface marking is point where lateral border of rectus abdominis crosses the right costal margin (point overlies the right 9th costal cartilage)
Neck continuous with cystic duct
Body = between fundus and neck
Surface marking of gall bladder fundus?
Point where lateral border of rectus abdominis crosses the right costal margin (point overlies the right 9th costal cartilage)
What is the bile duct?
Commences where CYSTIC duct and COMMON HEPATIC ducts join and ends at MAJOR DUODENAL PAPILLA where bile is deposited into lumen of the second part of the duodenum
- UPPER part (SUPRADUONDENAL part) lies within FREE MARGIN of lesser omentum with HEPATIC ARTERY and HEPATIC PORTAL VEIN
- LOWER part (RETRODUODENAL part) accompanied by HEPATIC PORTAL VEIN and GASTRODUODENAL ARTERY as they pass posterior to first part of duodenum
Downwards/right (INFRADUODENAL/pancreatic part)- lies in GROOVE on posterior surface of HEAD of PANCREAS, sometimes embedded in substance of pancreas tissue
Lowest part - passes through wall of duodenum - joined by main pancreatic duct = hepatopancreatic ampulla
What is the mechanism for storing bile in the gall bladder?
Sphincter around hepatopancreatic ampulla contracts - bile passes back up cystic duct (eventually) and into gallbladder
When sphincter open and gall bladder contracts, bile passes down cystic duct into bile duct and duodenum
What is important about the bile duct passing through the substance of the pancreas?
The lower part moves downwards/right and lies in groove on posterior surface of head of pancreas - sometimes embedded in substance of pancreas tissue
Gallstones (can be caused by inflammation of gallbladder) –> pancreatitis by blocking bile duct –> back pressure in main pancreatic duct
Pancreatic carcinoma may also block cystic bile duct and cause obstruction of bile flow –> jaundice
How is radiography of biliary system performed?
Gall bladder and duct system not normally visible on radiograph
Biliary tract may be outlined by ingestion of iodine containing medium which is then absorbed from the small intestine, carried to liver and concentrated in gall bladder
On some occasions, gall stones can be seen if they contain radio-opaque materials
What is the blood supply of the biliary tract?
Gall bladder supplied by CYSTIC ARTERY - most commonly arises from the right branch of the hepatic artery, although there can be considerable variation
Venous drainage by HEPATIC PORTAL VEIN
Nerve supply of biliary tract?
Sympathetic nerve supply from THORACIC sympathetic nerves via CELIAC GANGLIA
Postganglionic fibres accompany celiac artery and its branches to reach gall bladder and bile duct
- inhibits contraction of gall bladder, also pain impulses accompany sympathetics
Parasympathethic to gall bladder and bile duct from ANTERIOR VAGAL TRUNK - vagal fibres produce CONTRACTION of gall bladder and RELAXATION of the sphincter of the hepatopancreatic ampulla (sphincter of Oddi)
What is Murphys sign?
Typically positive in cholecystitis (inflammation of GB, often due to cystic duct blockage), but negative in choledocholithiasis (stones in common bile duct), pyelonephritis, and ascending cholangitis (infection bile duct)
Ask to breathe out - hand on gall bladder (midclavicular line, costal margin), then ask to breathe in - if painful/stops breathing in, positive sign (but must not be the same on the left)
Gall stone symptoms?
?
Epigastrium -
Right HC -
Near right scapula -
Right shoulder has referred to C3-C5 dermatome
Worse after fatty meal -
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