BIO 335 Cross Sectional Anatomy Bio 335 An

BIO 335: Cross Sectional Anatomy Bio 335 An unfortunate fact of the practice of modern medicine is that more hospitalized patients die of medical mistakes than any other single cause. Accuracy is of the utmost importance, especially in the communication of information and instructions. For this reason, for testing purposes, bilateral parts must be labeled right or left. Parts of organs must be fully identified. The upper pole of the left kidney can not be called the upper pole. The only abbreviations allowed are Rt or Lt for right or left. A for artery, V for vein, B for bone and M for muscle. Finally, spelling counts.

Unit 1 15 Transaxial CT Images of the Abdomen On campus students must draw and identify the anatomy on the linedrawings on the next slide. Students in the degree completion course should have an understanding of basic anatomy that makes testing on the drawings unnecessary. But if you need a refresher try the drawings. The ability to visualize is important to the study of cross sectional anatomy. These images of the abdomen start just below the diaphragm. They Continue in 1 cm increments through the abdominal cavity, ending just above the pelvis. First set of parenthesis, in bold, is page number for 3 rd edition Second set of parenthesis, not bold, is page number for 4 rd edition

Biliiary & Portal Drawings Can you draw & label (or visualize) these anatomical structures: An exercise in abdominal cross sectional anatomy recognition See plate 299, 302 (309, 312) Rt & Lt Hepatic ducts Common hepatic duct Cystic duct with spiral valves Common bile duct Pancreatic duct Hepatopancreatic ampulla (Ampulla of Vater) Sphincter of hepatopancreatic ampulla (Sphincter of Oddi) (287) Major duodenal papilla (Papilla of Vater) See plate 285 (294) Portal Circulation Inferior mesenteric vein Splenic vein Superior mesenteric vein Portal vein Rt & Lt branch of the portal vein Biliary Tree Liver sinusoids (283, 284) Hepatic veins (three) Inferior vena cava

7 10 2 8 1 4 3 9 5 6 12 15 13 11 14 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. Liver Reference Falciform ligament (279) (287) Thoracic aorta Abdominal essophagus* (267, 268) (275, 276) Rt. lung Lt. lung Images 1 & 2 Lt. rib Lt rib** Azygos vein (234) (238) Area Immediately below Lt. hemidiaphragm, containing the fundus of the stomach anterior to the spleen 11. Rt. lobe of liver 12. Lt. lobe of liver 13. Barium in haustra of splenic (Lt. colic) flexure (276) (284) 14. Spleen 15. Body of stomach with barium (white) and air (black)*** * Proximal to gastroesophageal (esophagogastric) junction (faintly seen as it approaches the stomach) ** Ribs are difficult to identify by number on axial scans, but when a rib is posterior to another it is also inferior: the rib numbered 8 is inferior to the one numbered 7 ***Typically the stomach is filled with barium, but this patient was unable to tolerate the full dose.

Images 1 -4

Reference Images 3 & 4 All anatomy seen in images 1 & 2 is also visible in 3 & 4, plus: 2 1 1. Branches of the Lt. branch of the portal vein* (282) (290) 2. CT artifacts 3. 4. 5. 6. 7. 8. 9. Transverse colon with air and barium contrast Descending colon with air and barium contrast Splenic vessel** (289) (299) Rt. & Lt. crus of diaphragm (262) (270) bottom Rt. & Lt. adrenal (suprarenal) glands Lt. branch of the portal vein Intrahepatic inferior vena cava*** (279) (287) 3 * On image 3 these branches of the portal vein have just bifurcated off the left branch of the portal vein (#8). Iodine contrast IV drip infused is increasing the density of the blood as the scan progresses. ** Veins and arteries cannot be differentiated at the highly vascularized hilum of the spleen. On later images it will be possible to identify major splenic vessels by their origins. ***The intrahepatic inferior vena cava has been in this position since image #1. The concentration of iodine contrast has just made it visible. Other white streaks throughout the liver are either branches of the portal vein or hepatic veins. 8 6 9 7 4 5

5 1 Images 5 & 6 1. 2. 3. 4. 5. 6. Ligamentum teres (fissure for) (279) (287) Lt. branch of the portal vein Caudate lobe of the liver Cystic duct of the gallbladder* Gas in the body of the stomach Rt adrenal (suprarenal gland) (322, 332 bottom) (332, 342 bottom) 7. Lt. adrenal (suprarenal) gland 2 3 4 Reference 7 6 8. Rt. branch of the portal vein 9. Lt. branch of the portal vein** 10. Intrahepatic inferior vena cava*** 11. Splenic vessels at the hilum of the spleen 12 Quadrate lobe of the liver (279) (287) 13. Upper pole of the Lt. kidney**** 12 10 8 11 9 13 * First appears in image 5, seen in 6, best seen in 7. ** This is the level of the bifurcation of the Lt. and Rt. branches of the portal vein. They persist on image 7. Image 8 is portal vein. *** At this level the vena cava is still intrahepatic, but will soon be out of the liver. ****The Rt. is also seen

Images 5 -8

Reference Images 7 & 8 1. Neck of gallbladder 2. Hepatic artery proper in the porta hepatis* (290) (300) 3. Quadrate lobe of liver (279) (287) 4. Caudate lobe of liver 2 3 1 4 5. Body of gallbladder 6. Portal vein 7. Inferior vena cava 8. Celiac axis (trunk) (290) (300) 9. Common hepatic artery 10. Splenic artery 11. Splenic vein 12. Atherosclerotic plaque in the abdominal aorta 13. Pyloric part of stomach** (267) (275) 14. Tail of pancreas * From the common hepatic artery (#9). Also, note Netter’s plate # 282 (290) which illustrates the portal triads, the three structures that follow each other through the liver: bile ducts, hepatic artery proper, and portal vein. All three are seen in the porta hepatis (hilum of the liver) in this section. **As the body of the stomach crosses midline and heads for the duodenum it becomes the pyloric antrum and then the pyloric canal just before the sphincter. 13 9 10 6 5 11 14 7 8 12

1 4 6 7 2 1. 2. Images 9 & 10 3. 4. 5. 6. 7. 8. 8 5 11 12 10 Fundus of the gallbladder Rt. Kidney* Rt. pararenal fat capsule (332) (342) First part of duodenum (cap, or bulb) Celiac axis (trunk)** Head of the pancreas Splenic vein*** Body of the pancreas (288) (298) 9. Superior mesenteric vein (289, 291, 292) (299, 301, deleted from 4 th) 10. Superior mesenteric artery 11. Gas and barium in the transverse colon 12. Barium in the descending colon 3 9 Reference * The kidneys, seen in images 6 -18, are bright (white) due to the IV iodine contrast saturating the nephrons and collecting tubules. ** The celiac axis seen here is the origin off the abdominal aorta. On image 8 (item 8) it continued to the bifurcation of the splenic and common hepatic. From this we conclude that on this patient the celiac axis turns upward after it leaves the aorta. ***The splenic vein seen here is a continuation of #11 on image #8. It is heading toward the pancreatic notch where it will anastomose with the superior mesenteric vein (#9 on image 10)

Images 9 -12

Reference 1. 2. 3. 4. 5. 6. Hepatic (Rt. colic) flexure Images 11 & 12 Lt. renal artery Superior mesenteric vein Superior mesenteric artery* Uncinate process of pancreas (288) (298) Lt. renal vein 1 6 7. Minor calicies (calyces) of Rt. kidney (321) (334) 8. Major calyx of Rt. kidney 9. Rt. renal vein** 10. Rt. renal artery 11. Lt. renal artery 12. Third part (transverse) of duodenum***(271) (280) 13 13. Rt. lobe of the liver 14. Transverse colon (with gas and barium) 2 14 12 * After the superior mesenteric artery and vein emerge from the pancreatic notch, the pair descends through the abdomen, diminishing in size. ** On image 10, the renal veins are first seen as small points off the inferior vena cava. On image 12 both renal veins are seen running through the inferior vena cava ***The second part of the duodenum (descending) is seen with gas in it on image 11 & 12. 3 4 5 9 10 7 8 11

1 2 4 5 3 Images 13 & 14 Reference 1. Transversus abdominus muscle (245) (253) 2. Lt. Internal abdominal oblique muscle 3. Lt. external abdominal oblique muscle 4. Lt. Renal pelvis* (321, 322) (334, 332) 5. Accessory Rt. renal vein** (324) (333) 6. Small bowel filled with barium 7. Inferior vena cava 8. Abdominal aorta 6 7 8 * Based on the size and position (emerging from the hilum) clearly defines the renal pelvis on both kidneys. **Like the first renal vein identified it leads to the inferior vena cava.

Images 13 -16

Reference 1. 2. 3. 4. 5. 6. 4 Transverse colon Ascending colon Loops of small bowel without barium Mesenteric vessels (arteries or veins)* Psoas major muscles (255) (263) Rt ureter (with iodine contrast) * Seen throughout the abdominal cavity Images 15 &16 1 3 2 6 5

Reference 1. 2. 3. 4. 1 Inferior mesenteric artery Lt. ureter Cecum of colon Lower pole of the Lt. kidney 2 Images 17 & 18 1 3 4

Images 17 & 18