Week 12: Gastrointestinal and Renal Care Flashcards
Location of pain is often described using the 9-region model - Visceral pain from the gut tube has a general pattern of referred pain regions. Where do foregut organs refer to?
Epigastric Region
Location of pain is often described using the 9-region model - Visceral pain from the gut tube has a general pattern of referred pain regions. Where do midget regions refer to?
Umbilical Region
Location of pain is often described using the 9-region model - Visceral pain from the gut tube has a general pattern of referred pain regions. Where do handgun regions refer to?
Hypogastric Region
surface anatomy: what is found at the Right costal margin
liver lower border
surface anatomy: what structures are found a Hand’s breadth below Xiphoid (L1):
Pylorus, duodenojejunal flexure, fundus of gallbladder, hila of kidneys
what clinically relevant structures are found on the Plane of Iliac Crests (L4):
Bifurcation of aorta, level of lumbar puncture
what anterior structure is found at T9?
Xiphoid
What is the surface anatomy of the liver
anterior, lateral and posterior surfaces are surrounded by the costodiaphragmatic recess, therefore pneumothorax a risk following percutaneous needle biopsy
What is the surface anatomy of the spleen
underlies 9/10/11th ribs, size of subjects cupped hand, must be 3x normal size to feel. Rib trauma can damage.
What is the surface anatomy of the gallbladder
fundus where right lateral border of rectus abdominis meets costal margin. Pressure at this point followed by pain = Murphy’s sign (cholecystitis)
What is the surface anatomy of the kidneys
Posterior abdominal wall, R lower than L, upper pole deep to 12th rib
What is the surface anatomy of the colon
when constipated stool can be palpated
What is the surface anatomy of the aorta
pulsations can be felt be firm downward palpation of abdomen in midline
Describe the surface anatomy of the abdominal wall muscles.
Anteriorly: Rectus abdominis inserts upon costal cartilages, xiphoid and crest of pubis
Rectus sheath formed by the aponeurotic expansions of the lateral wall muscles coming forward
Above vs. Below the Arcuate Line
Laterally: EO, IO and Transversus Abdominis contribute to rectus sheath and inguinal canal, and must be divided in surgery
Midline abdominal Incision:
Through linea alba, almost bloodless, very quick and easy access to entire abdomen
Paramedian abdominal Incision:
Advantage in that suturing the peritoneum the rectus abdominis slides back in place to cover and protect the deeper peritoneal sutures
Subcostal Incision:
Kocher incision, right side biliary surgery (Cholecystectomy) or left in spleen exposure
Gridiron Approach:
Appendectomy at McBurney’s Point splitting muscles
Pfannenstiel Incision:
Gynaecological surgeryCaesarian section, exposure of bladder/prostate
Peritonitis,
Inflammation and infection of the peritoneum. 3 causes:
Burst appendix
Penetrating wound
Perforated duodenal ulcer
Nerves of the Gut Viscera
SympatheticsFrom Sympathetic Trunk
Runs parallel to the vertebral column
Gives off multiple nerve plexuses in the abdomen via Splanchnic Nerves
End targets = organs, vessels, glands, etc. ParasympatheticsFrom Vagus nerve (CN X),
and Sacral Plexus
Has multiple plexuses in the abdomen
describe the Inferior Physiologic Sphincter of Oesophagus:
Circular layer of smooth muscle at terminal portion of organ
Tonic contraction prevents regurgitating
Diaphragmatic musculature forming the oesophageal hiatus aids as another physiologic sphincter Phrenicoesophageal Ligament
Achalasia
Failure of organized oesophageal peristalsis with impaired relaxation of the lower oesophageal sphincter (LOS)
Caused by degeneration of nervous innervation to organ
Results in dilation of the oesophagus and food stasis Dysphagia, fullness in chest
Each of the 3 oesophageal regions have nearby structures that produce IMPRESSIONS on oesophagusleading to potential constrictions. last these
Cervical: Caused by cricopharyngeus muscle Thoracic: Broncho-aortic arch
Abdominal: Oesophageal hiatus of the diaphragm
compare Rolling (Paraesophageal) Hiatal Hernia with a Sliding Hiatal Hernia
Rolling (Paraesophageal) Hiatal Hernia Medical emergency Fundus of stomach can become necrotic Diffuse Pain Acquired LESS common
Sliding Hiatal Hernia Failure of the phrenico-esophageal ligament Not a medical emergency Acquired Pyrosis (“heartburn”), dysphagia Displaced lower esophageal sphincter
Oesophageal Varices caused by…
Caused by Portal Hypertension
Must consider the fact that this is one area in the body that the Portal and Systemic systems meet up to drain
Veins follow arterial supply
Portal drainage: Oesophageal v.into L. Gastric veinPortal vein Liver
Systemic drainage: Oesophageal v.Azygos veinsHeart
Define Varix
Enlarged and tortuous vein, unnaturally swollen
anatomical considerations of Pancreatic Cancer:
Ofteninvadespancreatichead
Invasion can compress and obstruct the bile
duct, and/or hepatopancreatic ampulla
If cancer invades posteriorly, it can invade/block portal venous confluence of splenic + SMV
structure of Duodenum and four parts
C-shaped
Adjacent to the head of the pancreas
Connected to the liver by the hepatoduodenal ligament
4 Parts:
1. Superior Part“Duodenal cap”
2. Descending PartContains both the major and minor duodenal papillas (biliary and pancreatic juices enter organ here)
3. Inferior PartCrossed anteriorly by SMA and SMV
4. Ascending PartLigament of Treitz (suspensory ligament of duodenum) attaches this 4th part to the diaphragm above
Meckel’s Diverticulum
One of the most common congenital abnormalities
When connection between the intestine and umbilical cord doesn’t completely close off during development Resultoutpouching of the distal small bowel
Rule of 2’s!
Intussusception
Commonly involves the ileum and the proximal colonat the ileocolic junction
The proximal portion of the intestine telescopes INTO a distal segment of the intestinal tube
Cramping of the abdomen
Currant Jelly stooldark red and mucoid
Could lead to bowel perforation due to necrosisblood supply from SMA (ileocolic branches)
Diverticulosis
multiple false out-pocketings of mucosa of colon, common in sigmoid colon in middle aged/elderly, high fibre diet helpful in prevention
if infected and rupture diverticulitis
what do you see on imaging of Colonic Narrowing
Apple Core Sign
Associated with constriction of the lumen of the colon by a stenosing annular colorectal carcinoma
describe the structure of the Appendix
Narrow, hollow, blind-ended tube
Large aggregations of lymphoid tissue here
Location is highly variable from its “normal” position
Liver Venous Routes
Portal vein:
Final common pathway for the transport of venous blood from the abdominal part of the gastrointestinal tract, spleen, pancreas, gallbladder
Portal-Systemic anastomosis:
Specific type of anastomosis that occurs between the veins of the portal circulation (draining to liver) and those of the systemic circulation (those draining to heart)
Portal-Systemic Anastomosis
The anastomotic interconnections become dilated (varicosed) in case of portal hypertension Blockage of venous return A. Oesophageal varices B. Rectal varices (hemorrhoids) C. Caput medusae
What parts of the abdominal gastrointestinal tract comprise the i) Foregut ii) Midgut iii) Hindgut?
Foregut - Lower oesophagus, stomach first part duodenum, superior part of second part duodenum.
Midgut Rest of duodenum, jejunum, ileum, ascending colon, proximal ⅔ of the transverse colon.
Hindgut Rest of transverse colon, descending colon, sigmoid colon and most of rectum.
What is the blood supply to i) the foregut ii) the midgut iii) the hindgut?
Coeliac trunk, superior mesenteric artery, inferior mesenteric artery.
What does watershed area mean, where are they in the gut and what is the clinical significance?
Potential area of poor blood supply at edge of dual blood supply:
Between coeliac and SMA in second part duodenum (unusual to be ischaemic), between SMA and IMA at splenic flexure.
Splenic flexure ischaemia – mucosal slough, susceptibility to infection and perforation.
What anatomical features differentiate large bowel from small bowel?
Large bowel – large internal diameter, omental appendices (colon), segregation of longitudinal muscle into narrow bands (taeniae coli), sacculations of the colon (haustra)
What types of gall stones are there?
Cholesterol, pigment and mixed (calcium, pigment and cholesterol).
Which and what percentage of gallstones are radio opaque?
Mixed (Cholesterol and calcium containing) 20% are radio-opaque
Patient has a gallstone. Why has she become jaundiced?
Stone passed into the common bile duct causing obstruction
A 40-year-old woman attends the Emergency Department with right upper quadrant pain associated with nausea and vomiting. On examination, she is pyrexial with tenderness and guarding in the right hypochondrium. She has an ultrasound scan which shows gallstones
Your consultant asks you to arrange a MRCP. What is an MRCP and why might it be useful in this case?
Magnetic Resonance Cholangiopancreatography. The test can image the extra hepatic ducts and the pancreatic duct. It can evaluate the size of the ducts and if there are any stones present
A 40-year-old woman attends the Emergency Department with right upper quadrant pain associated with nausea and vomiting. On examination, she is pyrexial with tenderness and guarding in the right hypochondrium. She has an ultrasound scan which shows gallstones.
What is an ERCP?
Endoscopic retrograde cholangiopancreatography (ERCP) is a technique that combines the use of endoscopy and fluoroscopy to diagnose and treat conditions of the biliary or pancreatic ductal systems. Through the endoscope contrast medium is injected into the ducts in the biliary tree and pancreas so they can be seen on radiographs.
ERCP is used primarily to diagnose and treat conditions of the bile ducts and main pancreatic duct (including gallstones, strictures, leaks (from trauma and surgery), and cancer. ERCP can be performed for diagnostic and therapeutic reasons, although the development of safer and relatively non-invasive investigations such as magnetic resonance cholangiopancreatography (MRCP) and endoscopic ultrasound has meant that ERCP is now rarely performed without therapeutic intent.
ERCP can be used for diagnosis and for treatment. How can ERCP be used for treatment in gallstone disease?
Stones in the CBD can be removed by sphincterotomy and inserting a basket to withdraw the stones.
This abdominal x-ray is from a lady with gallstone disease that presented with colicky abdominal pain, vomiting and abdominal distension. X ray showed
- Air in biliary tree
- Small bowel obstruction
- Gallstone
Can you put it all together?
Fistula between fundus of gallbladder and duodenum. Stone passes through fistula and gets stuck in terminal ileum leading to small bowel obstruction.
Types of Hernias: A hernia that descends into the scrotum is likely to be…
indirect inguinal
Types of Hernias: A diffuse bulge medially over the inguinal canal is likely to be…
direct inguinal hernia
Types of Hernias: A hernia above and medial to the pubic tubercle is likely to be…
Inguinal
Types of Hernias: A hernia below and lateral to the pubic tubercle is likely to be…
Femoral
Types of Hernias: A hernia with digital pressure over the deep inguinal ring that appears medial to the point of pressure on coughing is likely to be…
Direct inguinal
Types of Hernias: A hernia with digital pressure over the deep inguinal ring that does not appear on coughing but appears on coughing with digital pressure removed is likely to be…
Indirect inguinal
Types of Hernias: A hernia that passes laterally to the inferior epigastric vessels is a…
Indirect inguinal
Types of Hernias: A hernia that passes medially to the inferior epigastric vessels is a…
Direct inguinal hernia
What are the relations of the inguinal canal anteriorly?
Anteriorly - Skin, superficial fascia, external oblique, internal oblique (lateral 1/3).
What are the relations of the inguinal canal posteriorly?
Posteriorly - Conjoint tendon (fused common insertion of internal oblique and transversus into pubic crest & pectineal line) medially and transversalis fascia laterally.
What are the relations of the inguinal canal above?
Above - arch of the lowest fibres of the internal oblique and transversus abdominis.
What are the relations of the inguinal canal below?
Below – inguinal ligament
Describe briefly an indirect inguinal hernia?
Congenital, persistent processus vaginalis, passes through deep ring, infancy early adult
Describe briefly a direct inguinal hernia?
Acquired, heavy lifting, coughing, straining, obesity, through posterior wall medial to inferior epigastric vessels.
borders of Hesselbach’s triangle
Inferior epigastric vessels, inguinal ligament, lateral rectus – direct hernia presents here
What are incarcerated, obstructed, and strangulated hernias?
Incarcerated – irreducible but not obstructed or strangulated,
obstructed – contents obstruction eg SBO,
strangulated – blood supply compromised – gangrene of contents.
Name the boundaries of the femoral ring?
Anteriorly – inguinal ligament
medially – lacunar ligament
posteriorly – pectineal ligament
laterally - femoral vein.
A 30-year-old man presents to the Emergency Department with haematemesis. He has a long history of epigastric pain radiating to the back. He is appropriately resuscitated and then taken to the endoscopy suite for an OGD which reveals a spurting vessel at the base of an ulcer crater in the posterior wall of the first part of the duodenum.
What anatomical structures has the endoscope traversed?
Oral cavity, oropharynx, pharynx, oesophagus, LOS, stomach (cardia, body, antrum, pylorus) duodenum.
A 30-year-old man presents to the Emergency Department with haematemesis. He has a long history of epigastric pain radiating to the back. He is appropriately resuscitated and then taken to the endoscopy suite for an OGD which reveals a spurting vessel at the base of an ulcer crater in the posterior wall of the first part of the duodenum.
What artery is likely to have been eroded in this case?
Posterior superior pancreaticoduodenal artery (branch of gastroduodenal) or gastroduodenal artery itself.
The lesser omentum extends from lesser curve of the stomach and the first part of the duodenum to the inferior surface of the liver. The free edge of the lesser omentum comprises the hepatoduodenal ligament. This lies anterior to the omental foramen.
What structures run in this free edge?
Portal vein, hepatic artery proper, bile duct.
What structure lies posterior to the omental foramen?
Inferior vena cava.
The omental foramen leads to what part of the peritoneal cavity?
Omental bursa (lesser sac).
A 65-year-old man presents to the Emergency Department with severe epigastric pain radiating through to the back. On examination, he was hypotensive and tender in the epigastrium. Blood tests revealed an elevated amylase and elevated bilirubin. A diagnosis of acute pancreatitis was made. An ultrasound scan of his showed gallstones.
Explain why gallstones may be a cause of acute pancreatitis?
One of the most common causes of acute pancreatitis in most developed countries (accounting for approximately 40% of cases) is gallstones passing into the bile duct and temporarily lodging at the sphincter of Oddi. It is thought that acinar cell injury occurs secondary to increasing pancreatic duct pressures caused by obstructive biliary stones at the ampulla of Vater.
A 65-year-old man presents to the Emergency Department with severe epigastric pain radiating through to the back. On examination, he was hypotensive and tender in the epigastrium. Blood tests revealed an elevated amylase and elevated bilirubin. A diagnosis of acute pancreatitis was made. An ultrasound scan of his showed gallstones.
Two days later he developed bruising around the umbilicus and in the flanks. i) what are these signs called ii) explain how and why the bruising occurs?
Periumbilical Cullen’s sign. Flank -Grey Turner’s sign.
Pancreas is a retroperitoneal structure. Bruising results from pancreatic enzymes causing fat necrosis and inflammation with retroperitoneal bleeding. Bleeding tracks from the retroperitoneum to the umbilicus
through the ligament teres / round ligament of the liver (Cullen’s sign) and from the retroperitoneum to the subcutaneous tissues of the flanks (Grey Turner’s sign). These signs are not specific but are associated with severe acute pancreatitis and high mortality.
A 40-year-old man is admitted to the emergency department following an episode of haematemesis. He admits to drinking at least half a bottle of vodka a day for many years. A diagnosis of bleeding oesophageal varices is considered.
What are oesophageal varices?
Swollen veins carrying excess blood flow as collateral drainage for schlerotic liver.
A 40-year-old man is admitted to the emergency department following an episode of haematemesis. He admits to drinking at least half a bottle of vodka a day for many years. A diagnosis of bleeding oesophageal varices is considered.
Why might the patient have portal hypertension?
Liver cirrhosis causes reduced blood flow to the liver raising in the portal pressure and blood drains into the systemic circulation via portosystemic anastomoses.
i) Where do portosystemic anastomoses occur?
ii) Which veins are involved? iii) What clinical signs occur in portal hypertension?
Distal 1/3 oesophagus.
Superficial veins lining mucosa -> left gastric vein -> portal vein and
tributaries of azygous (systemic).
Oesophageal varices.
Anus. Superior rectal vein (portal) with middle and inferior rectal (systemic).
Varices anorectal junction.
Anterior abdominal wall.
Para umbilical (portal) veins abdominal wall (systemic).
Caput medusa.
Using X-ray bony landmarks describe the course of the ureter.
Ureter descends retroperitoneally on the psoas major muscle which separates it from the tips of the transverse processes of the lumbar vertebrae. The ureter crosses into the pelvis anterior to the SIJ. Runs on the lateral wall of the pelvis in front of the ischial spine.
The ureter is constricted at three points in their course. i) Where are these? ii) What is their significance?
i) PUJ, where the ureter crosses the common iliac vessels at the pelvic brim, where the ureters enter obliquely into the bladder wall.
ii) Kidney stones can become lodged at these constrictions.
What is the blood supply to the ureter?
Upper end – renal arteries.
Middle part – abdominal aorta, testicular / ovarian arteries, common iliac.
Pelvic – branches of internal iliac.
Why does the pain of renal colic radiate to the scrotum / labia majora?
Visceral afferent fibres return to spinal cord at T11 – L2 levels. Therefore ureteric pain is referred to cutaneous areas supplied by T11 to L2.
What embryonic structure do the glomeruli and proximal duct system develop from?
Metanephros.
What embryonic structures do the collecting tubules, calyces, pelvis, ureter develop from?
Metanephric duct.
From your embryology knowledge, explain Congenital polycystic
kidneys
Failure of metanephric tissue to link up with metanephric collecting ducts.
From your embryology knowledge, explain: Horseshoe kidney.
Metanephric masses fused
From your embryology knowledge, explain: Pelvic kidney
Failure of ascent of kidney.
From your embryology knowledge, explain: Aberrant renal artery
Persistence of distally placed arteries (failure of artery involution as it ascends – starts in pelvis with blood supply from common iliac artery during migration a series of vessels supply it and then involute when renal artery takes over).
