SURFACE ANATOMY OF THE ABDOMENAbdominal Planes and Regions1. Divided by a number of imaginary horizontal vertical lines1. Also of value in defining approximate vertebral levels and the positions of some relatively fixed intra-abdominal structuresVertical Planes of the Abdomen1. Midline, which passes through the xiphisternal process and the pubic symphysis 1. Two Paramedian Planes, projected from the midclavicular line (lateral or mammary line)1. Approximates to, but does not exactly correspond to the lateral border of the rectus abdominisHorizontal Planes of the Abdomen1. Subcostal and transtubercular planes are common in clinical use1. Xiphisternal Plane runs horizontally through the xiphoid processes 1. It is at the level of the ninth thoracic vertebra1. Demacates the level of the cardiac plateau on the central part of the upper border of the liver1. Transpyloric Plane lies midway between the suprasternal notch of the manubrium and the upper border of the pubic symphysis 2. It is at the level of the body of the first lumbar vertebra2. Meets the costal margins at the tips of the ninth costal cartilage2. The Linea Semilunaris crosses the costal margin on the transpyloric plane1. Subcostal Plane is a line joining the lowest point of the costal margins3. Formed by the tenth costal cartilage on each side 3. Usually lies at the level of the body of the third lumbar vertebra1. Supracristal Plane joins the highest point of the iliac crest on each side4. lies at the level of the body of the fourth lumbar vertebra4. Marks the level of the bifurcation of the abdominal aorta4. Common level for the identification of the fourth lumbar vertebra4. Used to perform lumbar puncture at the L4 L5 or L5 S1 intervertebral level, safely below the termination of the spinal cord1. Transtubercular Plane joins the tubercles of the iliac crests5. Lies at the level of the body of the fifth lumbar vertebra5. Indicates or is just above the confluence of the common iliac veins 5. Marks origin of the inferior vena cava1. Interspinous Plane joins the centers of the anterior superior spines of the iliac crests 6. Passes through either the lumbrosacral disc or the sacral promontory6. Depends on the degree of lumbar lordosis, sacral inclination and curvature1. Plane of the Pubic Crest lies at the level of the inferior end of the sacrum or part of the coccyx Abdominal Regions 1. Can be divided into nine arbitrary regions by the subcostal or transtubercular planes and the two midclavicular planes projected onto the surface of the body1. Used for descriptive localization of the position of the mass or localization of a patients pain1. Nine regions formed are:2. Epigastrium2. Right and left hypochondrium2. Central or umbilical2. Right and left lumbar2. Hypogastrium or suprapubic2. Right and left iliac fossaTHE ANTERIOR ABDOMINAL WALLGeneral Characteristics of the Anterior Abdominal Wall1. Extends from the costal margins and xiphoid process superiorly to the iliac crest, pubis and pubic symphysis inferiorly1. Forms a continuous but flexible sheet of tissue across the anterior and lateral aspects of the of the abdomen1. Important role in maintaining the form of the abdomen 1. Form the inguinal canal that connects the abdominal cavity to the scrotumSkin and Soft Tissues of the Anterior Abdominal Wall1. Integument comprises skin, soft tissues, lymphatic and vascular structures and segmental nerves 1. Non-specialized and hirsute, depending on sex and race1. Subcutaneous fat is highly variable and is one of the areas where excess fat is stored during periods of obesity, particularly malesVascular Supply and Lymphatic Drainage1. Arterial Supply0. Superior Epigastric Artery0. Inferior Epigastric Artery0. Posterior Intercostal Artery0. Subcostal Artery0. Lumbar vessels1. Venous Drainage1. Follows the general course of the arteries1. Lymphatic Drainage2. Superficial Vessels0. Accompany the subcutaneous blood vessels2. Deep Vessels1. Accompany the deep arteriesStructures Associated with the Anterior Abdominal Wall1. Superficial Fascia0. Single layer0. Variable amount of fat0. Lies between skin and muscles 0. Differentiates into the superficial and deep layers1. Superficial Layer1. Thick, areolar in texture1. Contains variable amount of fat 1. Often greatly thickened in obese individuals1. Superficial to the inguinal ligament1. Continuous with the superficial fascia of the thigh1. In males, it continues over the penis and outer surface of the spermatic cord1. In females, it continues from the suprapubic skin of the abdomen into the labia major and perineum1. Deep (Membranous) Layer2. More membranous2. Contains elastic fibers2. Loosely connected by areolar tissue to the aponeurosis of the external oblique2. In midline, intimately adherent to the linea alba and symphysis pubis2. Continuous with the superficial fascia over the remainder of the trunk2. In males, it continues inferiorly and medially over the penis and spermatic cord to the scrotum2. In females, it continues into the labia majora and is continuous with the fascia of the perineum1. Transversalis Fascia3. Thin layer of connective tissue lying between the inner surface of transversus abdominis and the extraperitoneal fat3. It is part of the general layer of fascia between the peritoneum and the abdominal wall3. Attached to the entire length of the iliac crest 3. In the inguinal region it is thick and dense, augmentued by the aponeurosis of the transversus abdominis1. Extraperitoneal Connective Tissue4. Layer of areolar tissue lying between the peritoneum and the fascia lining the abdominal and pelvic cavities 4. Amount of tissue varies1. Most abundant on the posterior wall of the abdomen1. Particularly around the kidneys1. Often thickened in obese individuals4. Continuous with the epimysium of the muscles of the abdominal wall1. Rectus Sheath5. Encloses the rectus abdominis5. Anterior portion extends the entire length of the muscle1. Fuses with the periosteum of the muscle attachement5. Posteriorly, it is complete in the upper two thirds of the muscle, in the lower one third, it stops approximately midway between the umbilicus and the pelvis5. It is a clearly defined line, although transition may not always be clear5. Lower border of the posterior sheath is the Arcuate Line5. It is formed from decussating fibers from all three lateral abdominal muscles 5. All three anterior leaves run obliquely upwards5. Posteriorly leaves run obliquely downwards at right angles to the anterior leaves5. At midline, the anterior and posterior layers are closely approximated 5. Fibers of each layer decussate to the opposite side 9. It also decussates anteroposteriorly5. The dense fibrous line caused by this decussation is called the Linea Alba 1. Linea Alba6. Tendinous raphe 6. Extending from the xiphoid process to the symphysis pubis and pubic crest6. Lies between two recti 6. Formed by the interlacing and decussating aponeurotic fibers of the:3. External oblique3. Internal oblique3. Transversus abdominis6. Visible only in leand and muscular individuals4. Slight groove in the anterior abdominal wall6. A fibrous cicatrix, the Umbilicus, lies a little below the midpoint of the linea alba6. Covered by adherent area of skin6. Below the level of the umbilicus, it narrows progressively as the rectus muscles lie closer together6. It has two attachments at its lower end:8. Superficial fibers are attached to the symphysis pubis8. Deeper fibers form a triangular lamella that is attached behind the rectus abdominis to the posterior surface of the pubic crest on each side8. This posterior attachment is called the Adminiculum Linea Albae8. In the fetus, the umbilicus transmits the:3. Umbilical vessels 3. Urachus3. Vitelline or yolk stalk1. Conjoint Tendon7. Formed from the lower fibers of internal oblique and the lower part of the aponeurosis of transversus abdominis 7. Attached to the pubic crest and pectineal line 7. Acts to strengthen the medial portion of the posterior wall of the inguinal canal1. Inguinal Canal8. Natural hiatus in the tissues of the anterior abdominal wall8. Formed from the various layers of the wall in the region of the groin 8. Size and form vary with age8. Most well developed in males8. Contains the following structures:4. Spermatic cord in males4. Round ligament of the uterus in females4. Ilioinguinal nerve in both sexes1. Superficial Inguinal Ring9. Hiatus in the aponeurosis of the external oblique9. It is triangular, with its apex pointing along the line of the deep fibers of the aponeurosis 9. Varies in size 2. Does not usually extend laterally beyond the medial one third of the inguinal ligament2. Smaller in females9. The base lies along the crest of the pubis 9. It is only a distinct aperture when the continuity of this fascia with the aponeurosis is interrupted1. Deep Inguinal Ring10. Situated in the transverasis fascia10. Midway between the anterior superior iliac spine and the symphysis pubis, approximately 125 cm above the inguinal ligament10. Oval in shape10. Thin and with an almost vertical long axis10. Size varies among individuals10. Always much larger in males10. Traction on the ring exerted by the internal oblique may constitute a valve-like safety mechanism when intra-abdominal pressure is increasedMuscles of the Anterior Abdominal WallNote: Please see Table 1.5 They act together to perform a range of functions Generation of positive pressure within one or more body cavities Activities such as expiration, defecation and micturition may be aided Parturition, coughing and vomiting always require positive pressure Under resting conditions, the tone developed within the muscles provides support for the abdominal viscera and retains the normal contour of the abdomen Consequence of lack of muscular support can be seen in Prune Belly Syndrome Congenital absence of these muscles Active contractionnn of the muscles provide an important role in the maintenance of abdominal wall tone when the intra-abdominal pressure is increased

Muscles of the Anterolateral Abdominal WallMuscleOriginInsertionInnervationFunction

External obliqueMuscular slips from the outer surfaces of the lower eight ribs (ribs V to XII)Lateral lip of iliac crestAponeurosis ending in midline raphe (linea alba)Anterior rami of lower six thoracic spinal nerves (T7 to T12)Compress and protects abdominal contentsFlex trunk and bends trunk to same side, turning anterior part of abdomen to opposite side

Internal obliqueThoracolumbar fascia; iliac crest between origins of external and transversus; lateral two-thirds of inguinal ligamentInferior border of the lower three or four ribsAponeurosis ending in linea albaPubic crest and pectineal lineAnterior rami of lower six thoracic spinal nerves (T7 to T12) and L1Compress and protects abdominal contentsFlex trunk and bends trunk to opposite side, turning anterior part of abdomen to same side

Transversus abdominisThoracolumbar fascia; medial lip of iliac crest; lateral one-third of inguinal ligament; costal cartilages lower six ribs (ribs VII to XII)Aponeurosis ending in linea albaPubic crest and pectineal lineAnterior rami of lower six thoracic spinal nerves (T7 to T12) and L1Compress abdominal contents

Rectus abdominisPubic crest, pubic tubercle, and pubic symphysisCostal cartilages of ribs V to VIIXiphoid processAnterior rami of lower seven thoracic spinal nerves (T7 to T12)Compress abdominal contentsFlex vertebral columnTenses abdominal wall

PyramidalisAnterior surface of the pubis and pubic symphysisLinea albaAnterior ramus of T12Tenses the linea alba

Pathological Conditions Associated with the Anterior Abdominal Wall1. Divarication of the Recti0. Thinning and widening of the upper linea alba0. Result of obesity or chronic straining0. Increased intra-abdominal pressure causes the abdominal viscera to protrude beneath the thinned tissue as broad midline bulge0. Recti becomes widely separated0. Not a true herniation4. All layers of the abdominal wall in that region are intact1. Umbilical Hernia1. True Congenital Herniation0. Defect is present from birth0. Result of failure of closure of the umbilicus after retraction of the umbilical gut loop1. Infantile Umbilical Hernia1. Stretching of the umbical scar tissue1. Associated with intra-abdominal pressure1. Acquired Umbilical or Paraumbilical Hernia2. Occurs through small areas of weakness in the linea alba2. Above or below the umbilical scar1. Inguinal Hernia 2. Indirect Inguinal Hernia0. Arising lateral to the inferior epigastric vessels 0. Related to the congenital abnormal persistence of the vaginal process0. Others are required as a result of progressive weakening of the lateral and posterior walls of the canal0. May pass through the deep ring or may expand the deep ring0. Actual herniation into the potential sac may not occur until adult life0. It usually happens as a consequence of increased intra-abdominal pressure or sudden muscular strain2. Direct Inguinal Hernia1. Arising medial to the inferior epigastric 1. Caused by acquired weakeness of the inguinal triangle in the medial posterior wall of the canal1. May protrude through the transversalis muscle1. May closely resemble an indirect hernia1. Femoral Hernia3. Protrudes through the femoral ring3. The pubic tubercle is an important landmark in distinguishing inguinal from femoral hernias 1. If the neck is superomedial to it, it is inguinal1. But if it is inferolateral, it is femoral1. Lesions of the Intercostal Nerves4. Injury to a single nerve will not reduce the tone of the muscle wall4. Overlap between sequential dermatomes means that significant cutaneous anesthesia is appreciated only after sectioning of at least two sequential nerves

THE POSTERIOR ABDOMINAL WALLGeneral Structure of the Posterior Abdominal Wall1. Consists of fascia, muscles and their vessels and spinal nerves1. The overlying skin is continuous with that of the back1. It is not easily defined1. Best described as part of the abdominal wall lying between the two mid-dorsal lines, below the posterior attachments of the diaphragm and above the pelvis1. Continuous laterally with the anterolateral abdominal wall1. Spinal column forms part of its structure1. The major vessels and lymphatic channels, in addition to the peripheral nervous systems of the abdomen lie on the posterior abdominal wall6. Lie beneath the posterior parietal peritoneum6. Collectively referred to as the RetroperitoneumSkin and Soft Tissues of the Posterior Abdominal Wall1. Skin is similar to the rest of trunk1. Soft tissues are composed of several distinct layers of fascia1. Divides them into anatomically distinct compartmentsStructures Associated with the Posterior Abdominal Wall1. Thoracolumbar Fascia0. Three layers 0. Posterior layer is attached to the spines of the lumbar and sacral vertebra and to the supraspinous ligaments0. Middle layer is attached medially to the tips of the transverse processes of the lumbar vertebrae and the intertransverse ligaments 2. Inferiorly to the iliac crest 2. Superiorly to the lower border of the 12th rib and lumbocostal ligament0. Anterior layer covers the quadratus lumborum and is attached medially to the anterior surfaces of the transverse processes of the lumbar vertebrae 1. Psoas Fascia1. Enclosed within a layer of fascia over its anterior surface1. Medial border is continuous with the attachments of the muscle to the transverse process of the lumbar vertebrae1. Superiorly, the fascia forms part of the medial arcuate ligament1. Laterally, the fascia blends with the fascia over the quadrates lumborum in the upper part of the muscle and is continuous with the iliac fascia lower down1. It separates the mass of psoas major from the retroperitoneal structures lying on it1. Extends down into the thigh1. Thinnest in the groin1. Iliac Fascia2. Continuous with and indistinguishable from the psoas fascia2. Blends with the anterior layer of the thoracolumbar fascia over the quadrates lumborum in the upper retroperitoneum2. Attached firmly to the inner aspect of the iliac crest2. Attached in the abdomen to the iliopectineal eminence1. Perirenal Fascia3. Multilaminated fascial layer that surround s the kidney, suprarenal glands, upper ureter and associated fat0. All lie within the Perirenal Space3. Continuous with each other laterally and give rise to the lateroconal fascia at this point1. Lateroconal Fascia4. Formed from the lateral aspect of the perirenal fascia4. Extends anterolaterally to fuse with the fascia over the transversus abdominis4. Divides the anterior and posterior pararenal spaces from each other 4. Thinnest in the inferior part of the retroperitoneum1. Posterior Extraperitoneal Connective Tissues5. Contains loose connective tissue between fascial layers5. In all but the thinnest individuals, there is some adipose tissue present in these areas, and in obese, these are markedly thickened1. Bones6. Vertebral column and bony pelvis supports the posterior abdominal wall6. These include:1. Lower two ribs 1. 12th thoracic and five lumbar vertebrae1. Sacrum1. IliumMuscles of the Posterior Abdominal WallNote: Please see Table 1.61. Majority are functionally part of the lower limb or vertebral column1. Provide the surface against which the neurovascular structures of the retroperitoneum lie1. Supported and separated from the majority of the retroperitoneal structures by fascial layersPosterior Muscles (also the muscles of the iliac region)MuscleOriginInsertionNerve SupplyAction

IliacusIliac fossaLesser trochanter of femurFemoral nerveFlexes thigh on trunkIf thigh is fixed, it flexes trunk on thigh, as in sitting up from lying position

Psoas(Major and Minor)Transverse processes, bodies, and intervertebral discs of 12th thoracic and five lumbar vertebrae

Lumbar plexus

Quadratus lumborumIliolumbar ligament, iliac crest, tips of transverse processes of lower lumbar vertebrae12th ribFixes 12th rib during inspirationDepresses 12th rib during forced expirationLaterally flexes vertebral column same side

Pathological Conditions Associated with the Posterior Abdominal Wall1. Posterior Abdominal Wall Hernias 0. Extremely rare0. Because fascial layers usually provide an excellent protection against protrusion of the viscera1. The viscera are relatively immobile0. The posterior free border of external oblique and the inferior free border of the lattisimus dorsi create and area of potential weakness 2. This is referred to as the Lumbar TriangleVascular Supply, Lymphatic Drainage and Innervation of the Posterior Abdominal WallNote: Please see Table 1.7 for Arterial Supply 1. Venous Drainage0. Inferior Vena Cava conveys blood from all structure below the diaphragm0. Majority of its course is below the diaphragm0. Tributaries of the abdominal inferior vena cava include:2. Common iliac vein 2. Lumbar vein2. Right gonadal vein2. Renal vein2. Right suprarenal vein2. Inferior phrenic vein 2. Hepatic vein1. Lymphatic Drainage0. Divided into four regions0. The small upper left and upper right regions drain to the Lateral Aortic Nodes and the Ipsilateral Axillary Nodes0. The larger lower left and lower right portions drain to the Lateral Nodes and Retro-aortic Lymph Nodes0. Lymphatic drainage occurs exclusively through the Cisterna Chyli and the Thoracic Duct1. Innervation1. Mainly through the Lumbar Plexus1. The posterior abdominal wall contains its origins and numerous auntonomic plexuses and ganglia1. Lies close to the abdominal aorta and its branches

THE PERITONEUMGeneral Characteristics of the Peritoneum1. Largest serous membrane in the body1. In males it forms a closed sac1. In females it is open at the lateral ends of the uterine tubes1. The peritoneal cavity is a potential space between the parietal peritoneum1. It contains a small amount of serous fluid, but is otherwise empty 1. The fluid lubricates the visceral peritoneum and allows the mobile viscera to glide freely on the abdominal wall 1. It contains water, proteins, electrolytes and solutes derived from interstitial fluid 1. The peritoneal cavity never contains gas in normal circumstances7. Amount of fluid may be increased in inflammatory conditions of the viscera1. Extraperitoneal connective tissue separates the parietal peritoneum from the muscular layers of the abdominal walls1. The visceral peritoneum is firmly adherent to the underlying tissues and cannot be easily detached

THE LESSER OMENTUMGeneral Characteristics of the Lesser Omentum1. Formed of two layers of peritoneum separated by a variable amount of connective tissue 1. Derived from the ventral mesogastrium1. It runs from the inferior visceral surface of the liver to the abdominal oesophagus, stomach, pylorus and first part of the duodenum

THE GREATER OMENTUMGeneral Characteristics of the Greater Omentum1. Largest peritoneal fold 1. Hangs inferiorly from the greater curvature of the stomach1. It is a double sheet, with each sheet consists of two layers of peritoneum separated by a scant amount of connective tissue1. The two sheets are folded back on themselves and are firmly adherent to each other1. When the undisturbed abdomen is opened, the greater omentum is frequently wrapped around the upper abdominal organs4. Only rarely is it evenly dependent anterior to the coils of the small intestine1. It is usually thin and cribriform, but it always contains some adipose tissue and is a common site for storage of fat in obese individuals, particularly males1. The greater omentum is highly mobile and frequently becomes adherent to inflamed viscera within the abdominal cavity6. This action may help to limit the spread of infection 6. Provides a source of well-vascularized tissue to take part in the early reparative process6. It contains numerous fixed macrophages, that accumulate into dense, oval or round visible milky-spots'

Vascular Supply, Lymphatic Drainage and Innervation of the Peritoneum1. Arterial Supply0. Somatic blood vessels of the abdominal and pelvic walls1. Venous Drainage1. Follows the general course of the arterial supply1. Lymphatic Drainage2. Lymphatics join those in the body wall and drain to parietal lymph nodes1. Innervation3. The parietal peritoneum is innervated by branches from somatic efferent and afferent nerves that also supply the muscles and skin respectively of the overlying body wall3. The visceral peritoneum is innervated by branches of visceral afferent nerves which travel with the autonomic supply to the underlying viscera

ABDOMINAL AORTA begins at the median aortic hiatus of the diaphragm, anterior to the twelfth thoracic vertebras inferior border and the thoracolumbar intervertebral symphysis (disk), descending anterior to the vertebrae to end at the fourth lumbar, a little left of the midline divides into two common iliac arteries diminishes rapidly in caliber, since its branches are large Relations: Surface Anatomy When the abdominal wall is relaxed the aorta may be felt pulsating just above its bifurcation and its pulsation may be visible An easily palpable aorta in someone who is obese should raise the suspicion of an aneurysm Branches- may be described as ventral, lateral, dorsal and terminal; ventral and lateral distributed to the viscera, dorsal branches supplying the body wall, vertebral column, canal and its contents Ventral: celiac, superior and inferior mesenteric (MC) Dorsal: lumbar and median sacral (LS) Lateral: inferior phrenic, middle suprarenal, renal ovarian or testicular (PRO) Terminal: common iliac (CI)

VISCERAL BRANCHES

VENTRAL

Celiac TrunkRelations:Anterior omental bursa (lesser wall) celiac plexus surrounds the trunkRight Lateral right celiac ganglion right crus hepatic caudate processLeft Lateral: left celiac ganglion left crus cardiac end of the stomach right crus may compress the origin of the celiac trunk, giving the appearance of a stricture (celiac axis compression syndrome)Inferior pancreas and splenic vein duodenums suspensory muscle may encircle the celiac artery but is usually on its left Wide ventral branch, about 1.25 cm long, just below the aortic hiatus Passes almost horizontally forwards and slightlt right above the pancreas and splenic vein dividing into: left gastric, common hepatic, splenic arteries May also give off one or both inferior phrenic arteries BRANCHES (GaHaSa) Left Gastric Artery Smallest celiac branch Ascend to the left, posterior to the omental bursa, to the cardiac end of the stomach Near the stomach, two or three, oesophageal branches, ascend through the oesophageal opening to anastomose with the aortic oesophageal branches others supply the cardiac part of the stomach and anastomose with the splenic branches artery then turns antero-inferiorly into the left gastropancreatic fold to run (often doubled) curving to the right near the gastric lesser curvature to the pylorus supplies both gastric surfaces and anastomoses with the right gastric artery an accessory left gastric artery may arise from the left branch of the hepatic, also reaching the lesser curvature through the lesser omentum Hepatic Artery Intermediate in size between the left gastric and splenic arteries; but in later fetal and early postnatal life it is the largest celiac branch It first passes forwards and right, below the epiploic foramen Ascends between layers of the lesser omentum, anterior to the epiploic foramen, to the porta hepatic, where it divides into right and left branches to the hepatic lobes Artery may be subdivided into: Common hepatic artery- from the celiac trunk to the origin of the gastroduodenal artery Hepatic artery proper- from that point to its bifurcation Hepatic artery has right gastric, gastroduodenal and cystic branches, branches to the bile duct from the right hepatic and sometimes the supraduodenal artery Right Gastric Artery Arises above the duodenums superior part Passes left along the lesser gastric curvature, supplying the upper parts of the anterior and posterior gastric surfaces Ends by anastomosing with the left gastric Supraduodenal artery may be a branch Variable May arise from the gastroduodenal, hepatic (common, proper or latters branches) Supplies the superior half circumference of the proximal half or more of the duodenums superior part Gastroduodenal Artery Arises behind, sometimes above, the superior part of the duodenum It is short and wide Is usually left of the bile duct but sometimes anterior supplies small branches to the pyloric end of the stomach and to the pancreas, retroduodenal branches to the superior part of the duodenum and sometimes providing the supradoudenal artery At the lower border of the duodenums superior part it divides into right gastro-epiploic artery and superior pancreaticoduodenal arteries Most invariable feature is its intermediate position between the neck of the pancreas and the duodenum clinically important due to its frequent involvement in duodenal ulceration Right Gastro-Epiploic Artery Larger terminal branch of the gastroduodenal Skirts the right margin of the omental bursa and then turns left along the greater survature Ends in direct anastomosis with the left gastro-epiploic branch of the splenic; except at the pylorus, where it adjoins the stomach Also supplies the inferior aspect of the duodenums superior part Superior pancreaticoduodenal arteries Usually double: anterior descends anteriorly between the duodenum and head of the pancreas, supplying both Posterior superior pancreaticoduodenal artery Usually a separate branch of the gastroduodenal arising at the upper border of the duodenum Supplies the head of the pancreas and the duodenum Crosses posterior to the bile duct, piercing the duodenal wall Supplies several branches to the lower part of the common bile duct Cystic Artery Usually from the right branch of the hepatic proper Passes behind the common hepatic and over the cystic duct to the superior aspect of the gallbladders neck, on which it descends to divide into superficial and deep branches Accessory cystic artery may arise from the common hepatic or one of its branches Supplies the hepatic ducts and upper part of the common bile duct Reaches the gallbladder at its neck but is not in contact with the cystic duct Anteriorly: Two to five ascending vessels arise from the retrodoudenal branch of the gastroduodenal artery Three to four descending branches of the right hepatic and cystic arteries arise from them as these vesels pass close to the lower common hepatic duct Described as three oclock and nine oclock vessels Posteriorly: The retroportal artery arises from the celiac axis or superior mesenteric artery (or one of their major branches) close to the origin of the aorta can end in two different ways: in 20% = passes up behind the bile duct to join the right hepatic artery in majority = ends by joining the retroduodenal artery when present, plays a definite role in the blood supply of the supreduodenal duct system Terminal, interhepatic Branches Display a pattern of branching relatively constant in its major details, which justifies a segmental description of the liver Splenic Artery Largest branch of the celiac axis and remarkably torturous Ascends to the left, behind the stomach and omental burse, along the superior border of the pancreas Nearing the spleen it divides into five or more segmental branches which enters its hilum Pancreatic Branches They supply the neck, body and tail of the pancreas, leaving the splenic artery as it runs along its superior border A dorsal branch descends posterior to the pancreas dividing into: Right branch- runs between the neck and uncinate process to form a prepancreatic arterial arch Left branch- runs along the inferior border to the pancreatic tail Short Gastric Artery Five to seven, these arise terminally from the splenic and its final divisions or from the left gastro-epiploic artery Supply the gastric fundus Posterior Gastric Artery Arises from any part of the splenic but most commonly its middle section Ascends behind the peritoneum of the omental bursa towards the gastric fundud to reach the posterior gastric wall in the gastrophrenic fols Usually about 2 mm in diameter Left gastro-epiploic artery Splenics largest branch Arises near the splenic hilum and runs antero-inferiorly and right, sending branches through the gastrosplenic ligament to supply the proximal third of the greater curvature Longer than the gastric branches of the right gastro-epiploic artery and may be 8-10 cm long In partial gastrectomy, the greater omentum survives because its supply from this large omental branch of left gastro-epiploic artery usually escapes damage Terminal Splenic Branches Enter the hiulm in the lienorenal ligament

Superior Mesenteric Artery By far the most important of the arteries to the alimentary tract Supplies the whole of the small intestine from the superior part of the duodenum to the midtransverse colon, and functionally an end artery Leaves the front of the aorta about 1 cm below the celiac trunk, at the level of L1-L2 vertebral disk Runs downwards and forwards, anterior to the uncinate process, and passes in front of the transverse part of the duodenum Can sometimes be seen on a radiograph as an area of translucency, running across the duodenum, and was at one time thought to represent a sphincter (the sphincter of Ochsner) Fibrous strand from the region of its last branch runs to the umbilicus, and represents a vestige of the embryonic artery which originally connected it to the yolk sac Inferior Pancreaticoduodenal Artery Leaves the superior mesenteric artery, or it first jujenal branch, near the superior border of the horizontal part of the duodenum, usually dividing at once into anterior branch- passes to the right, anterior to the head of the pancreas, and ascends to anastomose with the anterior pancreaticoduodenal artery posterior branch- ascend to the right, posterior to the head of the pancreas supply the pancreatic head, its uncinate process and the adjoining duodenum Jejunal and Ileal Branches Arise from the left side of the superior mesenteric Usually 12-15 are distributed to the jejunum and ileum, except in the latters terminal par, which is supplied by the ileocolic artery From the terminal arches numerous straight vessels supply the intestine, distributed alternately to opposite aspects of its wall Jejunal arteries are longer and fewer in number Ileocolic Artery Last branch from the right side of the superior mesenteric Descend to the right under the parietal peritoneum to the right iliac fossa where it divides superior branch- anastomoses with the right colic inferior branch- approaches the superior border of the ileocolic junction and branches as follows: ascending (colic) passinf up on the ascending colon anterior and posterior caecal an appendicular artery, descending behind the terminal ileum to enter the mesoappendix an ileal branch ascending to the left on the lower ileum, supplying it and anastomosing with a terminal twig of the superior mesenteric artery Right Colic Artery Small vessel that may be absent Arises near the middle of the superior mesenteric or common with the ileocolic Near the colon, it divides into a descending branch which anastomoses with ileocolic, and an ascending branch ansatomosing with the middle colic Form arches, from which vessels are distributed to the ascending colon, supplying upper two-thirds and the right colic flexure Middle Colic Artery Leaves the superior mesenteric just inferior to the pancreas Divides into a right (anastomoses with the right colic artery) and left branches (anastomoses with the left colic artery which is a branch of inferior mesenteric artery)

Inferior Mesenteric ArteryRelations: divides into two or three branches, the uppermost of which (the left colic) almost always reaches the splenic flexure bifurcate: slender outer branch joins the left branch of the middle colic; the inner branch runs back into the trunk of the middle colic artery to form an additional arcade, the arc of Riolan there exists a critical area of anastomotic supply, so that impairment of flow either in the superior mesenteric or inferior mesenteris artery will not be compensated ischaemic damage may insue ( ischemic lesions at the region of the splenic flexure is relatively frequent

Supplies the left third of the transverse colon, all the descending colon, sigmoid colon and most of the rectum Smaller than the superior mesenteric, arising 3 or 4 cm above the aortic bifurcation, posterior to the horizontal part of the duodenum Descends behind the peritoneum, at first anterior to the aorta Enters and continues in the sigmoid mesocolon into the lesser pelvis as the superior rectal artery Has left colic, sigmoid and superior rectal branches Left Colic Artery Ascends subperitoneally to the left, anterior to the psoas major, and divides into ascending and descending branches Ascending branches passes anterior to the left kidney into the transverse mesocolon, where it anastomoses with the middle colic artery Descending branch anastomoses with the highest sigmoid artery Branches supply the left half of the transverse and the descending colon Sigmoid (Inferior Left Colic) Artery Two or three in number, they descend obliquely to the left under the peritoneum, anterior to the left psoas major, ureter and testicular or ovarian vessels Supply the lower descending colon and sigmoid colon Anastomoses above with the left colic artery, below with the superior rectal artery Superior Rectal Artery Continuation of the inferior mesenteric Descends into the pelvis in the sigmoid mesocolon, crossing the let common iliac vessels Divides, near the third sacral vertebra into two branches descending one on each side of the rectum About halfway they divide into smaller branches, which pierce the muscular rectal wall to the sphincter ani internus then communicates with the middle rectal aartery Marginal artery of the colon Formed by the union of the three main colonic branches which arise from the right side of the superior mesenteric artery Important vessel from the clinical point of view because in the event of an occlusion of the 2 upper vessels (celiac trunk, and the superior mesenteric artery) it represents the only surviving route of supply to the alimentary tract Arrangement of vessels along the right colon is fairly constant, there being one marginal artery giving of vasa recta and vasa brevia Clinical Anatomy superior mesenteric is occluded marginal artery to the colon is enormously dilated as it is required to supply the whole midgut loop occlusion to the aorta or common iliac arteries greatly dilates the marginal artery which then becomes an important source of collateral supply to the legs

LATERAL BRANCHES

Middle Suprarenal Arteries two small vessels arise laterally from each side of the aorta, level with the superior mesenteric its right branch passes behind the inferior vena cava and near the right celiac ganglion the left branch is related to the left celiac ganglion, splenic artery and superior border of the pancreas

Renal Arteries two large veins branch laterally from the aorta just below the inferior mesenteric, both cross the corresponding crus at right angles at the aorta right is longer and often higher, passing posterior to the inferior vena cava, right renal vein, head of the pancreas and descending part of the duodenum the left is a little lower, it passes behind the left renal vein, the body of the pancreas and splenic vein nearing its renal hilum, each divides into four or five branches each renal artery supplies small inferior suprarenal branches and also the ureter, surrounding cellular tissue and muscles

Gonadal Arteries

Testicular Arteries two, long, slender vessels that arise from the aorta a little inferio to the renal arteries the right lies anterior to the inferior vena cava and posterior to the horizontal part of the duodenum, right colic and ileocolic arteries, root of the mesentery and terminal ileum the left testicular artery lies posterior to the inferior mesenteric vein, left colic artery and lower part of the descending aorta crosses anterior to the genitofemoral nerve passes to the deep inguinal ring enters the spermatic cors with other constituents traverses the inguinal canal to the scrotum at the posterosuperior aspect of the testis it divides into two branches on its medial and lateral surface which passes through its tunica albuginea to ramify in the tunica vasculosa Clinical Anatomy: Testicular artery is not the sole supply to the testis, which also receives some blood from the cremasteric branch of the inferior epigastric artery Interruption in the region of the spermatic cord involves both sets of vessels leads to infarction

Ovarian Arteries Correspond to the testicular arteries but enter the pelvis to supply the ovaries At ovarian level it passes back in the mesovarium and divides into branches to the ovary Small branches supply the ureter and uterine tube and one passes to the side of the uterus to unite with the uterine artery

Inferio Phrenic Arteries(the competency says its a parietal branch but according to Mama Greys its a lateral branch and lateral branches supply the viscera (//_-) Two small vessels help to supply the diaphragm May arise separately from the aorta, just above its celiac trunk, by a common aortic stem or from the celiac trunk Left passes behind the oesophagus and forwards on the left side of its diaphragmatic opening the right phrenic passes posterior to the inferior vena cava then along right of its opening near the posterior border of the diaphragms central tendon each divides into medial and lateral branches lateral branch of the right artery supplies the inferior vena cava the left send ascending branches to the oesophagus each has two or three small superior suprarenal branches the liver and spleen also receive small branches from the phrenic arteries

PARIETAL BRANCHES (SILI)

DORSAL BRANCHES

Lumbar Arteries in series with the posterior intercostal arteries usually four on each side, they arise posterolaterally from the aorta, opposite the lumbar vertebrae run posterolaterally on the four upper lumbar vertebral bodies, behind the sympathetic trunk BRANCHES Has a dorsal branch passing back between the adjacent transverse process to supply the dorsal muscles, joints and skin Also supply the adjacent muscles, fasciae, bones, red marrow, ligaments and joints (symphyses, sundesmoses and synovial joint) Has a spinal branch that enters the vertebral canal to supply its contents and adjacent vertebra Spinal branches of the first lumbar supplies the terminal and spinal cord itself; the remainder supply the cauda equine, meninges and vertebral canal

Median Sacral Artery Small posterior branch that leaves the aorta a little above its bifurcation Descends in the midline, anterior to the fourth and fifth lumbar vertebrae, sacrum and coccyx, ending in the coccygeal body Often gives off a small artery (arteria lumbaris ima) , minute branch of which reach the rectum It anastomoses with the lateral sacral arteries and sends branches into the anterior sacral foramina

TERMINAL BRANCHES

Common Iliac Arteries abdominal aorta bifurcates, anterolateral to the left side of the fourth lumbar vertebral body, into the right and left common iliac arteries diverge as they descend to divide near the level of the lumbosacral interverteberal disc into external (supplies most of the lower limb) and internal iliac arteries (supplies the pelvic viscera and walls, perineum and gluteal regions

Right Common Iliac Artery 5cm long and passes obliquely across part of the fourth and fifth lumbar vertebral body Anteriorly it is crossed by the sympathetic rami of the pelvic plexus It is covered by the parietal peritoneum, which separates it from the coils of the small intestine Posteriorly Separated from the fourth and fifth lumbar vertebral bodies and their intervening disc by the sympathetic trunk, the terminal parts of the common iliac vein, the inferior vena cava, the obturator nerve, lumbosacral trunk and iliolumbar artery Lateral: inferior vena cava and right common iliac vein Medial: left common iliac vein

Left Common Iliac Artery About 4cm long Anterior: peritoneum, ileum, the sympathetic rami to the pelvic plexus, the superior rectal artery and its terminal bifurcation, the ureter the left common iliac vein is medial partly posterior to the artery; lateral and closely related is the left psoas major BRANCHES: each common iliac artery gives small branches to the peritoneum, psoas major, ureter, adjacent nerves and surrounding areolar tissue, occasionally it has the iliolumbar and accessory renal arteries as branches

VEINS OF THE ABDOMEN lumbar, renal, gonadal and suprarenal are described under the inferior vena cavaHepatic Vein drain the liver, commencing as intralobular veins, draining the sinusoid of liver lobules lead to sublobular veins united into hepatic veins emerges from the posterior hepatic surface to open at once into the inferior vena cava

Hepatic Portal System includes all the veins draining the abdominal part of the digestive tube with the exception of the lower anal canal, but including the abdominal part of the oesophagus also drains the spleen, pancreas and gallbladder portal vein and its tributaries have no valves blood passes through two set exchange vessels capillaries of the digestive tube, spleen, pancreas and gallbladder hepatic sinusoids

Portal Vein begins at the level of the second lumbar vertebra and is formed from the convergence of the superior mesenteric and splenic veins It is about 8 cm long and lies anterior to the inferior vena cava and posterior to the neck of the pancreas enters the right border of the lesser omentum, and ascends anterior to the epiploic foramen to reach the right end of the porta hepatic divides into right and left main branches which accompany the corresponding branches of the hepatic artery into the liver as it enters the left lobe it is joined by para-umbilical veins and the ligamentum teres, which contains the functionless and partly obliterated left umbilical vein connected to the inferio vena cava by the ligamentum venosuma vestige of an obliterated ductus venosus TRIBUTARIES

Splenic Vein formed by five or six tributaries emerging from the hilum of the spleen actually formed within the splenorenal ligament close to the tip of the tail of the pancreas thin walled and often spread over several centimetres as the hilum is long and thin ends behind the neck of the pancreas, where it joins the superior mesenteric vein to form the portal vein short gastric and left gastro-epiploic veins drain into the splenic vein through the folds of the gastrosplenic ligament near its origin TRIBUTARIES Short Gastric Veins Four or five short gastric veins drain the gastric fundus and the upper part of the greater curvature. drain into the splenic vein or one of its large tributaries Left Gastro-epiploic Veins drains both anterior and posterior gastric surfaces and the adjacent greater omentum receives multiple tributaries from the anterior and posterior surfaces of the body of the stomach and the greater omentum, and drains into the splenic vein within the gastrosplenic ligament Pancreatic Veins Drain the body and tail of the pancreas Inferior Mesenteric Vein Drains the rectum, and sigmoid and descending parts of the colon Begins as the superior rectal vein Passes above or behind the duodenal flexure, opening into the splenic vein

Superior Mesenteric Vein Drains the small intestine, caecum and ascending and transverse parts of the colon Ascends in the mesentery on the right of the superior mesenteric artery Joins the splenic vein behind its neck to form the portal vein TRIBUTARIES Right Gastro-Epiploic Vein drains the greater omentum, distal body and antrum of the stomach passes medially, inferior to the greater curvature, in the upper portion of the gastrocolic omentum may receive the superior pancreaticoduodenal vein close to its entry into the superior mesenteric vein Pancrestico-duodenal vein Accompany their corresponding arteries Left Gastric Vein drains the upper body and fundus of the stomach ascends along the lesser curvature to the oesophageal opening where it receives several lower oesophageal veins drains into the portal vein directly at the level of the upper border of the first part of the duodenum Right Gastric Vein typically small and runs along the medial end of the lesser curvature drains directly into the portal vein at the level of the first part of the duodenum receives the prepyloric vein as it ascends anterior to the pylorus at the level of the pyloric opening. Para-Umbilical Vein Connecting veins of the anterior abdominal wall and portal vein Extend along the ligamentum teres and median umbilical ligament End in the left branch of the portal vein Cystic Vein Drain the gallbladder

INFERIOR VENA CAVA conveys blood to the right atrium from all structures below the diaphragm formed by the junction of the common iliac veins anterior to the fifth lumbar vertebral body, a little to its right ascends anterior to the vertebral column, to the right of the aorta contained in a deep groove on the posterior surface of the liver, or sometimes in a tunnel completed by a band of liver tissue Relations of the Abdominal Part of the Inferior Vena Cava related to the right common iliac artery at its origin lies behind the peritoneum of the posterior abdominal wall and the third part of the duodenum lower three lumbar vertebral bodies, their intervertebral discs and the anterior longitudinal ligament and right psoas major, sympathetic trunk and third and fourth lumbar arteries are all posterior to the inferior vena cava the right ureter, the second part of the duodenum, medial border of the right kidney and the right lobe of the liver are all lateral to the right side of the inferior vena cava devoid of valves

Relation of the thoracic part very short partly inside and partly outside the pericardial sac the extrapericardial part is separated from the right pleura by the right phrenic nerve the intrepericardial part is covered, except posteriorly, by the inflected serous pericardium TRIBUTARIES

Lumbar Veins Four pairs of lumbar veins collect blood by dorsal tributaries from the lumbar muscles and skin first lumbar vein may drain directly into the ascending lumbar vein or pass forward over the first lumbar vertebral body to the lumbar azygos vein abdominal tributaries to the lumbar veins drain blood from the posterior, lateral and anterior abdominal walls, including the parietal peritoneum Near the vertebral column, the lumbar veins drain the vertebral plexuses and are connected by the ascending lumbar vein, which is a vessel running longitudinally anterior to the roots of the transverse processes of the lumbar vertebrae

Ascending Lumbar Vein connects the common iliac, iliolumbar and lumbar veins between psoas major and the roots of the lumbar transverse processes run forward over the twelfth thoracic vertebral body, and pass deep to the crura of the diaphragm and into the thorax ascending lumbar vein is usually joined by a small vessel from the back of the of the inferior vena cava or left renal vein on the left represents the azygos line and is referred to as the lumbar azygos vein

Gonadal Veins

Tesiticular Veins emerge posteriorly from the testis, drain the epididymis and unite to form the pampiniform plexus, which is a major component of the spermatic cord, and ascends anterior to the vas deferens In the inguinal canal the plexus is drained by three or four veins which run into the abdomen through the deep inguinal ring veins join to form single right or left testicular vein the right testicular vein opens into the inferior vena cava at an acute angle just inferior to the level of the renal veins left testicular vein opens into the left renal vein at a right angle contain valves Clinical Anatomy: Testicular vein in the scrotum and inguinal canal are frequently varicose, which is almost always on the left due to the orthogonal junction of the left testicular vein and renal veins raises temperature impairs fertility

Ovarian Veins emerge from the ovary as a plexus (pampiniform plexus) in the mesovarium and suspensory ligament usually merge into a single vessel before entering either the inferior vena cava on the right side, or the renal vein on the left side may contain valves much enlarged during pregnancy

Renal Veins large calibre vessels, which lie anterior to the renal arteries and open into the inferior vena cava almost at right angles left is three times longer than the right in length (7.5 cm and 2.5 cm, respectively) left vein lies on the posterior abdominal wall posterior to the splenic vein and body of the pancreas right renal vein lies posterior to the second part of the duodenum and sometimes the lateral part of the head of the pancreas Clinical Anatomy due to its close relationship with the aorta it may have to ligated in the course of, for example, operation for aneurysm

Suprarenal Vein right suprarenal vein drains directly into the inferior vena cava at the level of the twelfth thoracic vertebra

Inferior Phrenic Vein run on the inferior surface of the central tendon of the diaphragm drain into the posterolateral aspect of the inferior vena cava around the level of the tenth thoracic vertebra

Common Iliac Veins will be described under deep veins of the lower extremity

Hepatic Vein will be described under veins of the abdomen