Abdomen 9A Flashcards
Abdominal Cavity
A. Located between thoracic diaphragm & pelvic inlet
B. Lower ribs, muscular abdominal wall and pelvis protect viscera of abdomen
Two systems to describe location of structures in the Abdomen
9 Region System
Quadrant System
9 Region System
a. 2 horizontal planes
• transtubercular plane (level of iliac tubercles and body of L5)
• subcostal plane (level of inferior borders of 10th costal cartilage on each side)
b. 2 vertical planes
• R/L midclavicular plane
Naming the 9 Regions
• Center “column” (listed superior to inferior) (i) Epigastric (ii) Umbilical (iii) Hypogastric • Right and left lateral columns (listed superior to inferior) (i) Hypochondriac (R & L) (ii) Lumbar (R & L) (iii) Inguinal (R & L)
Quadrant System
a. horizontal plane
• transumbilical plane (level of umbilicus and L3-4 disc space)
b. vertical plane
• median plane
RUQ contains
(i) Liver/gallbladder,
(ii) pylorus of stomach, duodenum, large intestine – ascending & R ½ of transverse
(iii) head of pancreas
(iv) R kidney
LUQ contains
(i) L lobe of liver, jejunum & proximal ileum, large intestine – descending & L ½ of transverse
(ii) spleen
(iii) body & tail of pancreas
(iv) L kidney
RLQ contains
(i) Cecum, inferior portion of ascending LI, appendix
(ii) R ureter, bladder (if distended)
(iii) Some reproductive structures
1. Female: R ovary, R uterine tube, uterus if enlarged
2. Male: spermatic cord – abdominal part
LLQ contains
(i) Sigmoid colon, inferior portion of descending LI,
(ii) L ureter, bladder (if distended)
(iii) Some reproductive structures
1. Female: L ovary, L uterine tube, uterus if enlarged
2. Male: spermatic cord – abdominal part
Abdominal Wall
A. Technical divisions = anterior, lateral (flank) and posterior abdominal wall
B. However, for descriptive and functional purposes….anterolateral wall and posterior abdominal wall
Anterolateral Abdominal Wall (Clinical)
- patient presents with complaint of pain and noticeable bulge in the anterior groin region, increases with coughing and lifting …possible diagnosis?
a. Indirect inguinal hernia…bowel protrudes through inguinal canal into spermatic cord
b. Bowel pierces through weakened area of transverse fascia
2 Layers of Peritoneum
• Serous membrane that invests the abdominal structures
(i) Parietal layer - lines the wall of the abdominopelvic cavity
(ii) Visceral layer – covers the gastrointestinal structures
Transverse fascia
lines inner portion of the transverse abdominal muscle
• Continuous with linea alba
Superficial fascia composed of 2 layers of anterolateral wall
• Fatty layer = Camper’s fascia
• Membranous layer = Scarpa’s fascia….this is the inner layer & lacks fat
(i) This layer is continuous with other fascia layers in the perineum & reproductive organs (penis, clitoris & scrotum)
Multilayered wall of anterolateral wall of the abdomen
a. Skin
b. Superficial fascia composed of 2 layers
c. Deep fascia that invests the muscles of the abdominal wall
d. Muscles of the abdominal wall
e. Transverse fascia
f. Layer of extraperitoneal fat
g. 2 Layers of Peritoneum
external oblique (O,I,N,A)
(i) O: ribs 5-12 (external surfaces)
(ii) I: linea alba, pubic tubercle and anterior ½ of iliac crest
(iii) N: thoracic nerves (T5-12) Note: T12 is named the subcostal nerve
(iv) A: flex & rotate trunk, compress viscera (assists with expiration), support viscera/spine
(v) NOTE: inferior aponeuroses folds back on itself to form the inguinal ligament
Internal Oblique (O, I, N, A)
(i) O: thoracolumbar fascia, anterior 2/3 of iliac crest, lateral ½ of inguinal ligament
(ii) I: ribs 10- 12, linea alba, pectin pubis
(iii) N: thoracic nerves (T6-12) and first lumbar nerves
(iv) A: flex & rotate trunk, compress viscera (assists with expiration), support viscera/spine
transverse abdominal (O, I, N, A)
(i) O: costal cartilage of ribs 7 –12, thoracolumbar fascia, iliac crest, lateral 1/3 of inguinal ligament
(ii) I: linea alba, pectin pubis, pubic crest
(iii) N: thoracic nerves (T6-12) and first lumbar nerves
(iv) A: compress viscera (assists with expiration), support viscera/spine
rectus abdominis (O, I, N, A)
(i) O: costal cartilage of ribs 5 - 7, xiphoid process
(ii) I: pubic symphysis and pubic crest
(iii) N: thoracic nerves (T6-12)
(iv) A: flexes trunk, compress viscera (assists with expiration), support viscera/spine
3 Muscles of the Abdominal Wall
anterolateral wall
rectus sheath
linea alba
5 muscles of the Anterolateral wall
rectus abdominis transverse abdominal internal oblique external oblique pyramidalis
Rectus Sheath
• formed aponeuroses by the external oblique, internal oblique & transverse abdominal
• encloses rectus abdominis
• arcuate line (located between the level of the umbilicus & the pubic symphysis)
(i) above – posterior portion of rectus sheath covers the rectus abdominis
(ii) below – the rectus sheath travels anterior to rectus abdominis
Linea Alba
- Fibrous band of connective tissue located between the R/L rectus abdominis muscles
- Attachment for the oblique and transverse abdominal muscles
Inguinal Ligament
a. extends between ASIS (anterior superior iliac spine) and pubic tubercle
b. formed by the folded aponeurosis of external oblique
Clinical Implications of the Inguinal Canal
• Indirect inguinal hernia
(i) Bowel protrudes through deep ring and descends through canal
• Direct inguinal hernia
(i) Bowel protrudes through defect in anterior abdominal wall
(ii) Most common site of defect is Hesselbach’s triangle
(iii) Where is Hesselbach’s triangle?
1. Lateral border of rectus abdominis
2. Inguinal ligament
3. Inferior epigastric artery and vein
2 Openings to the Inguinal Canal
- Superficial (external) ring: formed by an arch in the external oblique aponeurosis
- Deep (internal) ring: formed by transverse fascia
Canal is formed by the connective tissue of the abdominal wall (4)
- Anterior: aponeurosis of external & internal oblique
- Posterior: transverse fascia
- Superior: fibers of the transverse abdominal and internal oblique arch over
- Inferior: inguinal ligament (remember formed by the inferior fold of external oblique)
Contents of the Inguinal Canal depending on Gender
- Males: spermatic cord and ilioinguinal nerve
* Female: round ligament of uterus and ilioinguinal nerve
Peritoneal cavity
- thin potential space between the visceral and parietal peritoneum
- NOTE: the peritoneal cavity is NOT same as the abdominal cavity the peritoneal cavity is within the abdominal cavity
Mesentery
- double layered fold of peritoneum d/t the organ invaginating on the peritoneum (again…visualize the pressing in on a balloon)
- “suspends” or connects the organ to the posterior abdominal wall
- Contains blood vessels, lymphatic vessels and nerves that supply structure suspended by the mesentery
Greater omentum
peritoneal fold that hangs down from the greater curvature of the abdomen and loops back up to attach to the transverse colon
Lesser omentum
double layer of peritoneum that attaches to the stomach (and proximal duodenum) and then attaches to the liver
Peritoneal ligament
doubled layer of peritoneum that attaches an organ to the abdominal wall or another organ…two examples are….
• Falciform ligament…attaches liver to anterior abdominal wall
• Gastrosplenic ligament…attaches spleen to the stomach
Peritoneum and Peritoneal Cavity
a. Parietal layer – lines internal walls of abdominopelvic cavity
b. Visceral layer – lines the abdominal viscera
c. Mesentery
d. Greater omentum
e. Lesser omentum
f. Peritoneal ligament
g. Peritoneal cavity
h. Retroperitoneal vs intraperitoneal space
3 Divisions of the Abdominal Viscera
Foregut
Hindgut
Midgut
Hindgut
a. distal 1/3 of transverse colon to anus
b. Blood supply - inferior mesenteric artery
Midgut
a. hepatopancreatic ampulla (of Vater) to distal approximately 1/3 of transverse colon
b. Blood supply - superior mesenteric artery
Foregut
a. oropharynx to hepatopancreatic ampulla (of Vater) located in duodenum
b. blood supply – celiac trunk
Esophagus (Clinical)
a. MC s/s of esophagus disease = heartburn
• Esophageal reflux
(i) Dysfunction of the lower esophageal sphincter (LES)
• Hiatal hernia…two types
(i) Sliding hiatal hernia – cardia of stomach and esophagus herniate through diaphragm
(ii) Paraesophageal hiatal hernia – fundus herniates through diaphragm..no heartburn…possible strangulation/obstruction may occur
Anatomy of the Esophagus
a. Muscular tube connects pharynx to the stomach
b. Descends in superior and posterior mediastinum
c. Passes through diaphragm in esophageal hiatus
d. Gastroesophageal junction is location where esophagus and stomach meet
e. Upper esophageal sphincter (UES)
f. Lower esophageal sphincter (LES)
Lower esophageal sphincter (LES)
- Junction of esophagus and stomach
* Smooth muscle…not easily identified
Upper esophageal sphincter (UES)
- junction of pharynx and esophagus
* inferior pharyngeal constrictor muscles and cricopharyngeus muscle
Stomach (Clinical)
a. MC s/s stomach disease = nausea/vomit
• Gastric ulcer
(i) Usually in body along lesser curvature
(ii) Caused by damage to mucosal barrier…d/t smoking, aspirin or NSAID’s
(iii) Helicobacter pylori infection in 70% of patients
Anatomy of the Stomach
a. Divisions – cardia, fundus, body & pylorus
b. greater and lesser curvatures
c. stomach wall
• 3 muscular layers…oblique, circular, longitudinal
d. rugae (gastric folds)
• large longitudinal in mucosal folds of stomach
• will flatten out with food in stomach
e. pyloric sphincter
• connects stomach to small intestine
Patient presents with severe pain in epigastric region that decreases after a meal…possible diagnosis?
• Duodenal ulcer (usually proximal portion)
• Caused by …
(i) hypersecretion of gastric acid
(ii) damage to mucosa
• Helicobacter pylori infection in100% of patients (he-lick-oh-back-ter pie-lorrie)
• worse on an empty stomach and relieved temporarily by food, antacids, or milk.
Patient presents with abdominal pain, fever, wt. loss, fatigue/weakness, intermittent diarrhea…what is possible diagnosis?
- Crohn’s disease
- Chronic inflammatory bowel disease…MC in the ileum
- Often will see “skip areas” in the small intestine
- Obstruction = colicky pain = smooth contractions of small intestine (ilium)
Duodenum
- Approximately 25 cm (approximately 10 inches)
- Proximal portion has mesenteric attachments and is “intraperitoneal”
- Then duodenum becomes “retroperitoneal”
Major landmark of internal surface = hepatopancreatic ampulla (of Vater)
(i) Common bile duct and the main pancreatic duct (of Wirsung) enter the SI along the descending portion of the duodenum via the heptopancreatic ampulla (of Vater) and the main duodenal ampulla
1. Pancreas…secrete digestive enzymes
2. Gall bladder…secrete bile
Jejunum
• Loops tend to be found in the LUQ
• Landmark of jejunum: Ligament of Treitz
(i) Peritoneal fold at junction of duodenum and jejunum
Ileum
- loops tend to be found in the RLQ
- terminates at ileocecal valve…connection to cecum of large intestine
- site of vitamin B12 absorption
Patient presents with abdominal pain, severe diarrhea, bloody stools…possible is diagnosis?
• Ulcerative colitis
(i) Ulcerations of colon and rectum, rectal bleeding, mucosal abcesses
(ii) Can cause anemia, electrolyte imbalances…potential for peritonitis, toxic megacolon (dilation of transverse colon and may perforate the wall of the intestine) and cancer
Patient presents with chronic diarrhea, flatulence, wt. loss and fatigue…possible diagnosis?
• Celiac disease (celiac sprue)
(i) Hypersensitivity to gluten found in wheat, barley, rye and other whole grains
(ii) When gluten is ingested causes excessive immune response (lymphocytes, plasma cells, eosinophils, macrophages accunulate in lamina of mucosa….end result = damage to mucosa)
Clinical for Large Intestine
a. MC s/s of colon disease = diarrhea
b. MC s/s of anorectal disease = bleeding
Patient presents with pain in epigastric or umbilical region…migrates to RLQ, nausea, vomit, severe tenderness to palpation….possible diagnosis?
• Appendicitis
(i) Appendix becomes obstructed (fecal matter or lymphoid hyperplasia) causing dilation of appendix (distention of causes pain)
(ii) McBurney’s Point – located midway between ASIS and umbilicus
(iii) Complication if rupture = Peritonitis
Divisions of the Large Intestine
• Appendix (vermiform appendix)…located in RLQ (will vary), McBurney’s point (approximately halfway between ASIS and umbilicus)
• Cecum….junction of ileum and large intestine….ileocecal valve separates
• Ascending colon….retroperitoneal
• Transverse colon….intraperitoneal
• Descending colon…retroperitoneal
• Sigmoid colon…becomes intraperitoneal again
(i) Diverticula = abnormal sacs or pouchs
(ii) Diverticulitis = inflammation or rupture (perforation) of the diverticula
(iii) Primary function = storage of feces
• Rectum
Anatomy of the Large Intestine
a. 1.5 meters long (approximately 4-5 feet)
b. external wall of large intestine
• taeniae coli - 3 bands of longitudinal muscle…converge at appendix
• haustra - sacculations of the LI formed by contractions of the taeniae coli
Patient presents with history of blunt trauma to left posterior ribs, diagnostic imaging reveals severe rib fractures of left ribs 9-10…what other structure would be at risk?
• Spleen
(i) Splenectomy might be appropriate
(ii) Complications of spleenctomy
1. atelactasis (collapse) of left lung
2. thrombocytosis (increased platelets in the blood)…thus increased risk of thrombus formation…anticoagulation therapy indicated
(iii) Bone marrow and liver remove RBCs after splenectomy
Anatomy of the Spleen
a. located in LUQ and is “protected” by lower ribs 9-12, difficult to palpate if WNL
b. located “intraperitoneal”
c. attached to stomach (gastrosplenic ligament) and left kidney (splenorenal ligament)
d. spleen located near tail of pancreas
e. if enlarged can be palpated with patient right lateral decubitus position
Function of the Spleen
a. Filter RBC’s – removes old or abnormal RBC’s
b. Storage of platelets
c. Lymphatic/immune functions…protect against infection, produce immunoglobulin M (IgM), etc..
Patient presents with epigatric pain that radiates to the back, nausea, vomiting, elevated amylase and lipase levels, history of alcoholism…what is a possible diagnosis?
- Acute pancreatitis
* Also caused by biliary tract disease…example stone lodged in ampulla
Patient presents with epigastric pain that radiates to the back, wt. loss and obstructive jaundice…what is a possible diagnosis?
Pancreatic cancer (pancreatic adenocarcinoma)
What is the role of the pancreas in insulin dependent diabetes?
- Beta Cells of Islets of Langerhans – damage to cells cause decrease in insulin
- Elevated blood glucose levels (prolonged GTT) and in urine…
- Chronic…neuropathies, retinopathy, nephropathy, degenerative changes in large and small blood vessels
4 divisions and location of the pancreas
a. 4 divisions of pancreas…..head, neck, body & tail
b. location of pancreas
• retroperitoneal space
• crosses midline of abdomen (clinical pain may cross midline…)
• head in close contact with duodenum
• tail in close contact with spleen
Ducts of the Pancreas
• Main pancreatic duct (of Wirsung)
(i) Joins with bile duct to form the hepatopancreatic ampulla (of Vater) and opens into the descending portion of the duodenum via the major duodenal papilla (see description below)
• Accessory duct (of Santorini)
(i) Also enters the duodenum
Function of the Pancreas
a. Endocrine…Islets of Langerhans release endocrine hormones (glucagons, insulin, somatostatin & pancreatic polypedtide)
b. Exocrine – digestive enzymes split carbohydrates, fats and proteins
Functional divisions of the liver
• Right and left portions of the lobe that operate independently of each other
• An imaginary line between the gall bladder and the IVC demarcate the functional divisions…this line is known as Cantlie’s Line
• Each division has it’s own blood supply, portal system and bile drainage system
• NOTE: 4 anatomical lobes = left lobe, caudate lobe, quadrate lobe & right lobe
(i) Functional right lobe = anatomical right lobe
(ii) Functional left lobe = anatomical left, quadrate and caudate lobes
Surface of the Liver
• Diaphragmatic surface– dome shaped to match the contour of the diaphragm
(i) Anterior, superior, posterior portion of the liver
• Visceral surface – primarily posterior and inferior
Anatomy of the Liver
a. Located in right and left upper quadrants
b. Located in “intraperitonel” space
c. “Suspended or attached” in peritoneal cavity via…
• Falciform ligament – peritoneal fold attaches to the anterior abdominal wall
• Lessor omentum – peritoneal fold attaches to lesser curvature of the stomach
• Hepatic veins that connect to the IVC
Functions of the Liver
- Filter circulating toxins, drugs, hormones, old blood cells, etc…
- Active role in metabolism of carbohydrate, protein and fat
- Endocrine functions
- Plays role in activation of Vitamin D
- Synthesis and secretion of bile
Pathway of Bile from the Liver
- bile secreted from liver via R/L hepatic ducts…
- these ducts merge into the common hepatic duct which…
- drains into bile duct which…
- merges with the main pancreatic duct and forms the hepatopancreatic ampulla (of Vater)…
- opens into the small intestine via the major duodenal papilla
- NOTE: bile will be stored in & released from the gallbladder via the cystic duct
What is Bile?
- composed of H2O, electrolytes, bilirubin (bile pigment), cholesterol, calcium and cholic/chenodeoxycholic acids conjugated to glycine or taurine to form bile salts
- Bile salts function is to
a. emulsify fats (breaks down fats into smaller globules)
b. assist in transporting fats across small intestine membrane - The bilirubin in the bile is the remainder of the broken down RBC and can be excreted
a. RBC breaksdown – HAEM is converted to bilirubin and attaches to albumin in the blood (this known as unconjugated bilirubin)
b. It travels to the liver where it becomes conjugated bilirubin
What is pathway of bile after it enters GI tract?
- bile enters SI
a. some of the bile salts and bilirubin are reabsorbed and returns to the liver
b. some of the bile salts breakdown fats
c. the remaining unconjugated bile salts will follow two pathways
i. the unconjugated bile salts are reabsorbed and return to the liver
ii. the unconjugated bile salts are excreted in the feces
d. the remaining bilirubin is excreted in the feces
What is hyperbilirubinemia?
- excessive unconjugated bilrubin in the bloodstream if liver is damaged…pigment causes yellow discoloration of sclera (icterus) and the skin (jaundice)…may see also bilirubinuria – gold/brown discoloration in the urine
How does the Liver receive Oxygen?
- The liver also has a direct arterial supply from the heart via the hepatic artery
- 30% of the blood flow to the liver is from the direct arterial (oxygen rich) supply of the hepatic artery
- 70% of the blood flow to the liver is via the oxygen-poor blood from portal vein
What is the porta hepatis?
- It is the exit/entrance for the portal vein, hepatic ducts (drain bile) & hepatic artery
- Located on the visceral surface of the liver
Hepatic portal system
a. “Portal” refers to a vein located between two capillary beds
b. In this case…the capillary beds are those of the gastrointestinal tract and the liver
c. So how does it work?
• Blood travels from the heart to the GI tract
• There it delivers O2 to the GI structures and picks up the nutrients from the GI tract
• It takes the nutrients directly to the liver via the portal vein
• After filtering through the liver the blood leaves the liver via the hepatic veins and eventually drain into the IVC
What is ascites?
(i) Accumulation of fluid within the peritoneal cavity d/t portal hypertension
What is portal hypertension?
• Cirrhosis (destruction of hepatocytes and replacement with fibrous tissue) and other pathologies will impair the flow of blood through the liver
• The blood flow will “reverse” and flow into the IVC system via 3 anastomoses
• Where are the 3 anastomoses that provide reversed blood flow in portal hypertension?
(i) Esophagus…forms esophageal varices, can bleed causing blood in vomit
(ii) Rectum…forms hemorrhoids
(iii) Epigastric veins in anterior abdominal wall…forms “caput medusae”
1. caput medusae = dilated superficial veins of abdomen
(iv) sometimes the 3 pathways memorized as “gut, butt and caput”
Patient presents with acute epigastric pain, migrates to RUQ (or right hypochondriac region)…possible diagnosis? (gallbladder)
• Gallstone obstruction in cystic duct
(i) Initial epigastric pain…obstruction of cystic duct (biliary colic)
(ii) Gallbladder itself becomes inflamed (acute cholecystitis)
(iii) No jaundice…bile flow from the liver okay
• Obstruction within common bile duct
(i) Stone will obstruct bile flow from gallbladder and liver (jaundice)
(ii) Rarely obstructs whole duct…moderate jaundice (fluctuates)
(iii) Obstruction causes inflammation of gall bladder and liver
• Obstruction at hepatopancreatic ampulla
(i) Stone will obstruct bile flow from gallbladder and liver (jaundice)
(ii) Stone may also obstruct pancreatic duct (pancreatitis)
Note: 3 types of stones…
Cholesterol stones- obesity, CF, wt loss, Crohn’s, estrogen use
MOST COMMON form of gallstones
Bile is the only way to excrete cholesterol so if too much cholesterol it will form stones
Bilirubin stones – chronic RBC hemolysis, alcoholic cirrhosis, biliary infection
Calcium stones – infection or inflammation of biliary tree
Anatomy of the Gallbladder
• Located in gallbladder fossa of visceral surface of the liver
• Also in close proximity with the proximal duodenum
• Cystic duct – leaves gall bladder to merge with common hepatic duct
(i) Bile travels to and from the gallbladder via cystic duct
(ii) As bile leaves the cystic duct it merges with the bile duct which in turn merges with the main pancreatic duct to form the hepatopancreatic ampulla (of Vater)…
(iii) which opens into the duodenum via the main duodenal papilla
(iv) sphincter of the bile duct is located at the distal end if the bile duct
1. if contracted – bile is unable to flow to SI and backs up into the gallbladder for storage
Retroperitoneal (9)
a. Duodenum except proximal portion
b. Ascending colon
c. Descending colon
d. Rectum
e. Pancreas except the tail
f. Suprarenal glands
g. Kidneys
h. Ureter
i. Abdominal Aorta and IVC
Intraperitoneal (9)
a. Stomach
b. Proximal duodenum
c. Jejunum
d. Ileum
e. Transverse colon
f. Sigmoid colon
g. Liver & gallbladder
h. Tail of pancreas
i. Spleen
Patient presents with sudden onset of severe central abdominal pain, may radiate to the back, pulsing mass may be palpated or auscultated…what is possible diagnosis?
(Blood Supply to Viscera of Abdominal Cavity)
- Triple “A”…AAA = abdominal aortic aneurysm
- Common sites = just inferior to renal arteries or just proximal to bifurcation into common carotid arteries
- Inferior mesenteric artery often part of the balloon of the aneurysm
- If patient survives rupture…potential surgery risks = ischemic colitis…what part of the gut?..hindgut supplied by inferior mesenteric artery, spinal cord ischemia also risk if great radicular artery is damaged during surgery = anterior spinal cord syndrome
Celiac Trunk (Abdominal Aorta descending branches)
(i) Which part of the gut does it supply?
1. Foregut (oropharynx to hepatopancreatic ampulla (of Vater) located in duodenum)
(ii) So which structures are supplied by celiac trunk?
1. Esophagus, stomach, proximal duodenum, liver/gall bladder, pancreas and spleen
(iii) 3 branches of celiac trunk…common hepatic artery, splenic artery, left gastric artery
So which structures are supplied by superior mesenteric artery?
Small intestine (distal to heptopancreatic ampulla), large intestine (cecum, appendix, ascending colon, proximal 2/3 of transverse colon)
Which part of the gut does it supply?
superior mesenteric artery
Midgut …hepatopancreatic ampulla (of Vater) to distal approximately 1/3 of transverse colon
How does the superior mesenteric artery supply these structures?
- via the mesentery
- mesentery provides route for artery, vein, nerves and lymphatics (lacteals “drain” ingested fats from small intestine)
Renal and Gonadal Arteries
- Right/left renal arteries – supply kidneys
- Right/left gonadal arteries – supply testes or ovaries (also passes through inguinal canal with ductus deferens or round ligament of the uterus)
Which part of the gut does it supply?
Inferior mesenteric artery
- Hindgut….distal 1/3 of transverse colon to anus
Common iliac arteries
(i) terminal branches of abdominal aorta
(ii) bifurcation at L4
