L4.2+4.3 Ab viscera

Question 1

How is the abdominal quadrants divided?

Answer 1

• Horizontal line through umbilicus
• Vert line from sternum to pubic symphysis

Question 2

Esophagus

Answer 2

• Muscular tube, 25cm
• Conduct food from pharynx to stomhac via peristalsis
• Enters stomach from the L of side, into R side of somtach

Question 3

Esophogastric junction (Z-line)

Answer 3

• Changes from esophageal mucosa to gastric mucosa
  
  • Stratified squamous epithelium → simple columnar epithelium)

Question 4

Esophageal narrowings

Answer 4

• Cervical: Upper esophageal sphincter
• Thoracic: Aortic arch & LMB
• Abdomen: Diaphragmatic orifice

Question 5

BS of the esophagus (ab part only)

Answer 5

• L gastric branch from aorta

Question 6

Venous drainage of the esophagus (ab part only)

Answer 6

• L gastric portal

Question 7

Herniation of the stomach

Answer 7

• Sliding hiatal hernia: Through esophagus
• Paraesophageal hernia: Next to esophagus

Question 8

Stomach

Answer 8

• LUQ, intraperitoneal
• J-shaped → have greater & lesser curvature
• Cardiac orifice (Prox opening of R border)
• Pyloric orifice (distal opening)
• Fundus (part that projects upwards above the cardio orifice - usually full of gas)
• Body
• Angular notch (on lesser surface where body ends - begins to funnel down)
• Pyloric antrum (funnel bit)
• Pylorus (converges on the most tubular & distal part)
  
  • Has a pyloric sphincter - controls gastric outflow into duodenum
• Rugae (gastric folds in stomach - more predominant twd pylorus)

Question 9

Mesentery of the stomach

Answer 9

• Lesser omentum: Connected to under surface of liver on the lesser curvature of stomach
• Greater omentum: connects stomach to POS wall

Question 10

BS to the stomach

Answer 10

• Gastroepiploic vessels running along curvatures

Question 11

Duodenum

Answer 11

• Retroperitoneal (but 1st inch is intraperitoneal → hasn’t made it back to POS wall), 25cm
• C-shaped loop surrounding head of pancreas
• Site of digestion & absorption of digestive products
  
  • Villi → ↑SA → ↑Abs

Question 12

Duodenum 1) Duodenal cap

Answer 12

• 5cm
• Upwards & backwards (adjacent to R.crus, overlying hilum of R. kidney)
• Ulcers tend to form (due to imbalance of gastric contents & acid)

Question 13

Duodenum 2) Descending vertical part

Answer 13

• 7.5cm
• Vertical descent on R.psoas next to head of pancreas
• Has transverse mesocolon (surrounds the transverse colon)
• Have pailla

Question 14

Duodenum 3) Horizontal part

Answer 14

• 10cm
• Has root of mesentery of SI
• R to L.psoas in front of IVC & aorta, at level of L3

Question 15

Duodenum 4) Ascending part

Answer 15

• DJ flexure
• Curves forward

Question 16

Duodenal papilla

Answer 16

• On P-M wall 1/2 down of 2nd part of duodenum
• Major: where common bile duct & pancreatic duct enters
• Minor: position is higher than maj, where accessory pancreatic duct enters

Question 17

Jejunum + Ileum

Answer 17

• 4-6m
• Starts at DJ flexure
• 2/5 jejenum, 3/5 ileum

Question 18

Differences b/w jejunum & ileum

Answer 18

• Jejunum has ↑abs
  
  • ∴↑mucosal folds, thicker walls…
• Jejunum (LUQ), Ileum (RLQ)
• Jejunum has long vasa recta, few arcades
• Ileum has short vasa recta, lots of arcades

Question 19

BS to SI

Answer 19

• Arcades: Mesenteric A arranged in loops
• Vasa recta: long projections twd intestines

Question 20

LI

Answer 20

• Frames the central coils of the SI
• Muscle coats:
  
  • Inner circular coats
  • Outer longitudinal muscle coats
    
    • Forms 3 discrete muscle bands → Teniae Coli
    • Bands are shorter than mucosal tubes → creates Haustra (sacs of LI)
• Epiploic appendices (fat tags) → unique to LI

Question 21

Caecum

Answer 21

• Retroperitoneal
• Begins with ileum ends
• Blind pouch behind ileocaecal valves

Question 22

Ileocecal junction

Answer 22

• Has ileocaecal valve (mucosa covering anatomical sphincter)

Question 23

Appendix

Answer 23

• Hangs off base of caecum, where 3 teniae coli meet (fixed)
• Variable length
• Contains modules of lymphoids
• Tips of appendix is variable
  
  • Pelvic appendix (~25%) → hangs twd pelvis
  • Retrocaecal appendix (~65%) → tucked up behind A.colon

Question 24

Rectum

Answer 24

• No teniae along rectum
• Longitudinal fibres becomes continuous

Question 25

Liver

Answer 25

• RUQ, Intraperitoneum
• 2 surfaces: diaphragmatic (smooth) & visceral (has adjacent structure impressions)

Question 26

Liver: Diaphragmatic surface

Answer 26

• Has sharp INF edge of liver
• Falciform ligament → divides into 2 functionally equal lobe (but R anatomically larger than L)

Question 27

Falciform ligament

Answer 27

• Double fold mesentery
• Connects to ANT wall
• Down to level of umbilicus → becomes the ligamentum teres (round ligament) → obliterated after birth → Remnant umbilical V in fetus

Question 28

Liver: Visceral surface

Answer 28

• Hilum of liver (creates H-shape fissure → creates 2 more lobes)
  
  • Quadrate (INF)
  • Caudate (SUP)
• Quadrate + Caudate + L lobe → functional L lobe
• Gallbladder b/w R lobe & quadrate lobe
• IVC embedded into V surface b/w R lobe & caudate lobe

Question 29

Ligamentum venosum

Answer 29

• Remnant of ductus venosus
• Connects portal V & directly drains into IVC
• Used by bypassing liver in fetus

Question 30

Hilum (porta hepatis)

Answer 30

• Structures all divide into R/L
• Left of hilum: Proper hepatic A
• Right of hilum: Hepatic duct → brings bile out (R+L = common hepatic duct)
• Back of hilum: Portal V → venous drainage from GI tract (all the products from GI presented to liver)

Question 31

Venous drainage of the liver

Answer 31

• IVC embedded in visceral surface (doesn’t come out of hilum)
• Hepativ veins drain directly into IVC

Question 32

Epiploic foramen

Answer 32

• Able to see hilum structures

Question 33

Gallbladder

Answer 33

• Stores & concentrate bile prod. From liver
• Sits in groove of visceral surface of liver
• Fundus of gallbladder hangs below INF margin of liver, corresponding with R.costal margin & with R. Rectus abdominus
  
  • Able to palpate if gallbladder is infected (i.e. from gallstones etc…)

Question 34

Pathway of the gallbladder

Answer 34

• Fundus → Body (narrows) → Neck (narrowed further) → Cystic duct → joins common hepatic duct → becomes common bile duct → along edge of L.omentum → behind 1st of part duodenum → groove b/w head of pancreas of 2nd part of duodenum → maj papilla

Question 35

Hepatopancreatic sphincter

Answer 35

• At the terminal portion of pancreatic & bile duct
• Closed in resting state, relaxes only in the presence of fatty meals

Question 36

How is bile stored in the gallbladder

Answer 36

• Bile comes from liver → sphincter closed → bile moves back into cystic duct → gallbladder

Question 37

How is bile released from the gallbladder

Answer 37

• Fatty meal → gallbladder contracts → bile out

Question 38

Pancreas

Answer 38

• Has exocrine functions (using ducts) & Endocrine functions (released into bloodstream ∴ rich BS)
• Head:
  
  • Within C-shaped duodenum
  • Uncinate process (landmark to identifying SUP mesenteric vessels)
• Neck
  
  • Deep to pylorus of stomach
• Body
  
  • Above DJ flexure
• Tail
  
  • Leads directly to hilum of spleen

Question 39

Ducts of pancreas

Answer 39

• Begins at tails → joins common bile duct → maj duodenal papilla
• Accessory pancreatic duct:
  
  • Drains uncinate process

Question 40

Spleen

Answer 40

• Oval shaped, variation in size
• Atrophy with age

Question 41

Spleen: Diaphragmatic surface

Answer 41

• Smooth & characterised by notches

Question 42

Spleen: Visceral surface

Answer 42

• Colic (colon impressions), Gastric, Renal surfaces
• Hilum → splenic A & V (VERY VASCULAR)
  
  • A travels along SUP border of pancreas into hilum

Question 43

Position of the spleen

Answer 43

• LUQ, above L. splenic flexure
• Beneath diaphragm

Question 44

Relationship of the spleen with the ribs

Answer 44

• Directly related to ribs 9-11
• Axis along shaft of 10th rib
• Fractured ribs → pierces spleen