The Abdomen

1. The Abdomen Surface Anatomy, Vessels, Muscles, and Peritoneum

2. Anterior abdominal wall extends from costal margin to inferior boundaries: Iliac crest Anterior superior iliac spine Inguinal ligament Pubic crest Superior boundary Diaphragm Central landmark Umbilicus Linea alba (white line) Tendinous line Extends from xiphoid process to pubic symphysis Surface Anatomy

3. 9 regions 4 quadrants Draw “line” through navel Right upper quadrant Left upper quadrant Left lower quadrant Right lower quadrant Abdominal Quadrants

4. Function: Help contain abdominal organs Move trunk Forced breathing Increase intra-abdominal pressure Abdominal wall Anterior (4) Innervated by intercostal nerves Continuous with layers of intercostal muscles Fibers of layers run in different directions for strength Ends in aponeurosis which contains rectus abdominis muscle Posterior (3) Muscles

5. Rectus Abdominis Origin Pubic crest, symphysis Insertion Xiphoid process, costal cartilages of ribs 5-7 Function Flex, rotate trunk, fix and depress ribs, stabilize pelvis, compress abdomen Internal oblique Origin Lumbar fascia, iliac crest, inguinal ligament Insertion Linea alba, pubic crest, last 3-4 ribs, costal margin Function Same for external obliques Anterior Abdominal Wall Muscles

6. External oblique Origin Lower 8 ribs Insertion Aponeurosis to linea alba, pubic and iliac crest Function Flex trunk, compress abdominal wall (together), Rotate trunk (separate sides) Transversus abdominis Origin Inguinal ligament, lumbar fascia, cartilage of last 6 ribs, iliac crest Insertion Linea alba, pubic crest Function Compress abdominal contents Anterior Abdominal Wall

7. Iliopsoas Psoas major Origin Lumbar vertebrae, T12 Insertion Lesser trochanter of femur via iliopsoas tendon Function Thigh flexion, trunk flexion, lateral flexion Innervation Ventral rami L1-L3 Iliacus Origin Iliac fossa, ala of sacrum Insertion Lesser trochanter of femur via iliopsoas tendon Function Thigh flexion, trunk flexion Innervation Femoral nerve (L2 and L3) Psoas minor – variable (40-60% do not have) Posterior Abdominal Wall

8. Quadratus lumborum Origin Iliac crest and lumbar fascia Insertion Transverse process of upper lumbar vertebrae, lower margin of rib 12 Function Flex vertebral column, maintains upright posture, assists in inspiration Innervation: T12 and upper lumbar spinal nerves (ventral rami) Posterior Abdominal Wall

9. Ventral body cavity Thoracic Abdominopelvic Abdominopelvic Abdominal Liver Stomach Kidneys Pelvic cavity Bladder Some reproductive organs Rectum Abdominopelvic Cavity

10. Abdominal cavity The space bounded by: • Anterolateral abdominal wall • Posterior abdominal wall • Diaphragm • Pelvic walls and pelvic floor. Subdivided into: • True abdominal cavity (from diaphragm tolinea terminalis) • Pelvic cavity (belowlinea terminalis).

11. Peritoneum and peritoneal compartment Peritoneumis a continuous serous membrane, composed of two layers: • Parietal peritoneum, lines abdominal and pelvic wall • Visceral peritoneum, lines abdominal and pelvic organs. Peritoneal compartmentis part of the abdominal cavity enclosed within theparietal peritoneum. Contains organs covered with peritoneum and peritoneal structures. Outside the parietal peritoneum is the extraperitoneal compartment of the abdominal cavity.

12. Peritoneal cavity Peritoneal cavity(PC) - the spacebetween the two peritoneal layers, is a potential space, into whichthe organs are tightly packed against each other. • PCcontainsthin layer of fluid, which lubricates the peritoneal surfacesand allows movement of the organs without friction. • PCisclosed in males, butcommunicates with the external environment in femalesthrough the uterine tubes, uterus and vagina. • Peritoneum, peritoneal cavityand all the organs are situated in the abdominal cavity.

13. Development of the peritoneum

14. Relationship between the organs and peritoneum Due to intraembryonal processes the organs have different relationship with the peritoneum. 1. Intraperitoneal organsare entirely covered with peritoneum. They are connected to the abdominal wall withligaments or meso, which ensures greater mobility. 2. Extraperitoneal organsare partially or entirely devoid of peritoneum. They areslightly movableor immovable. According to their position these are: а) retroperitoneal – on the posterior abdominal wall b) subperitoneal – in the lesser pelvis c) preperitoneal – at the anterior abdominal wall.

15. Vertical layout of the peritoneum

16. Horizontal layout of the peritoneum

17. Passage of the parietal into visceral peritoneum

18. Peritoneal structures 1. Mesentery –double peritoneal layer, representing elongation of the visceral peritoneum. • М. connects the corresponding organ with the abdominal wall (e.g.,mesentery of the small intestine). • М. contains connective tissue in which are embedded blood vessels, nerves and lymph nodes. • М. ensures mobility of the organs.

19. 2. Omentum – double layered structure of visceral peritoneal, extending from the stomach to neighbouring organs. • Lesser omentum (оmentum minus) connects the lesser curvature of the stomach and intitial portion of pars superior duodeni with liver. • Greater omentum (оmentum majus) descends from the greater curvature of the stomach and intitial portion of pars superior duodeni, covers the intestines, and then ascends back to attache to the transverse colon. Contains great amount of fat tissue.

20. 3. Peritoneal ligaments – double layered structures of visceral peritoneum, between neighbouring organs or between organ and abdominal wall(e.g., lig. falciforme, lig. gastrophrenicum, lig. gastrolienale, lig. gastrocolicum). 4. Peritoneal folds (plicae) formed over underlying structures (e.g., plica iliocecalis superior, plica umbilicalis mediana). 5. Peritoneal recessuses – spaces in the peritoneal cavity заградени between peritoneal structures and abdominal organs or abdominal wall (e.g., bursa omentalis, recessus subphrenicus, fossa retrocecalis).

21. Divisions of the peritoneal cavity By mesocolon transversum the peritoneal compartment divites into: 1. Supracolic compartment – between diaphragmand mesocolon transversum with its mesentery. 2. Infracolic compartment - between mesocolon transversum and linea terminalis. 3. Pelvic compartment - below linea terminalis in the pelvi cavity.

22. Supracolic compartment Organs: 1. Esophagus, pars abdominalis - intraperitoneal 2. Stomach - intraperitoneal 3. Liver - intraperitoneal 4. Gall bladder - intraperitoneal 5. Spleen - intraperitoneal

23. Supracolic compartment. Projections of organs

24. Supracolic compartment Peritoneal structures: 1. Lig. falciforme hepatis • lig. teres hepatis 2. Lig. coronarium hepatis (dextum et sinistrum) • area nuda 3. Lig. triangulare (dextum et sinistrum)

25. Supracolic compartment 4. Omentum minus • lig. hepatogastricum • lig. hepatoduodenale 5. Omentum majus • lig. gastrocolicum • lig. gastrolienale • lig. gastrophrenicum 6. Lig. phrenicolienale

26. Supracolic compartment Peritoneal spaces: 1. Recessus subphrenicus dexter - bursa hepatica 2. Recessus subphrenicus sinister - bursa pregastrica 3. Perilienal space 4. Recessus subhepaticus а) anterior part b) posterior part - recessus hepatorenalis 5. Bursa omentalis

27. Supracolic compartment Bursa omentalis. Opened thru lig. hepatogastricum Bursa omentalis. Opened thru lig. gastrocolicum

28. Infracolic compartment Organs: 1. Small intestine • duodenum (pars superior, descendens, horizontalis, ascendens) - retroperitoneal, pars superior intraperitoneal • Jejunum and ileum - intraperitoneal 2. Large intestine • cecum - intraperitoneal • appendix vermiformis - intraperitoneal • colon (ascendens, transversum, descendens, sigmoideum) - intraperitoneal /mesoperitoneal • rectum – most extraperitoneal

29. Organs and projections

30. Peritoneal structures 1. Omentum majus - pars libera 2. Mesenterium 3. Mesocolon transversum 4. Mesocolon sigmoideum 5. Mesoappendix

31. Peritoneal structures 1. Plicae duodenalis superior/inferior - recessus duodenalis superior/inferior 2. Plicae ileocecalis superior/inferior - recessus ileocecalis superior/inferior

32. Peritoneal spaces 1. Canalis lateralis dexter 2. Sinus mesentericus dexter 3. Sinus mesentericus sinister 4. Canalis lateralis sinister 5. Recessus intersigmoideus 6. Recessus retrocecalis

33. Appendix vermiformis

34. Supracolic compartment. Blood supply Truncus celiacus 1. A. gastrica sisnistra - r. esophageus 2. A. hepatica communis - a. hepatica propria - a. hepatica dextra/sinistra - a. gastroduodenalis - a. gastroepiploica dextra - aa. pancreaticoduodenales superiores (anterior/posterior) - a. gastrica dextra 3. A. lienalis - aa. gastricae breves - a. gastroepiploica sinistra

35. Supracolic compartment. Blood supply

36. Arteriogram of truncus celiacus

37. Infracolic compartment. Blood supply A. mesenterica superior 1. A. pancreaticoduodenalis inferior 2. Aa. intestinales (15-18) 3. A. iliocolica 4. A. colica dextra 5. A. colica media

38. Infracolic compartment. Blood supply A. mesenterica inferior 1. A. colica sinistra 2. Aa. sigmoideae (3-4) 3. A. rectalis superior