1.ABDOMEN AND ITS LAYERS WITH BOTH .pptx

Anatomy of the abdomen

1. THE ABDOMEN BY TERRY

2. Why study the abdomen Abdominal pains, abdominal swellings, and blunt and penetrating trauma to the abdominal wall are common problems that face the clinicians. Abdominal problems are complicated by the fact that the abdomen contains multiple organ systems, and knowing the spatial relationships of these organs to one another and to the anterior abdominal wall is essential In making accurate and complete diagnosis. The abdominal wall is a flexible structure through which the physician, surgeon and gynecologist can often feel diseased organs that lie within the abdominal cavity. A defect or malfunction of the wall can allow the abdominal contents to bulge forward and form a hernia.

3. Surface markings

4. Viscera of the anterior part of the abdominal cavity

5. Viscera of the posterior part of abdominal cavity

6. I ntroduction A bdomen :part of the trunk that lie between the thorax and the pelvis. It is important to know what organs are located in each abdominal region or quadrant so that one knows where to auscultate , percuss , and palpate them normally, in cases of pains , or pathologies. The four quadrants and 9 regions

7. ABDOMINAL PLANES 1.Transpyloric Plane It is an imaginary horizontal plane which lies about one hand’s breadth below the xiphisternal joint. Anteriorly it passes through the tip of the 9th costal cartilage and posteriorly through the lower border of the body of L1 vertebra. Is the key plane of the abdomen as it corresponds to the pylorus of stomach

8. 2. Subcostal Plane It is an imaginary horizontal plane, which passes immediately below the costal margins. It passes anteriorly through the lowest borders of costal cartilages of the 10th rib, and posteriorly through the body of L3 vertebra. 3 . Trans-umbilical Plane It is a transverse plane that passes through the umbilicus and lies at the level of intervertebral disc between the L3 and L4 vertebrae.

9. 4. Intertubercular Plane It is an imaginary horizontal plane which joins the iliac tubercles. It passes through the upper part of the body of L5 vertebra. 5. Right and Left Vertical/lateral Planes (also called Midclavicular Planes) They pass from the midpoint of the clavicle superiorly to the point midway between the anterior superior iliac spine and the pubic symphysis inferiorly, i.e., mid-inguinal point.

10. Regions of the abdomen

11. Cont …. The abdominal cavity is divided into 4 quadrants by transumbilical plane and vertical median plane. The abdominal cavity is divided into 9 regions by: Two transverse (horizontal) planes- transpyloric plane and intertubercular plane(most commonly ) or subcostal and interspinous planes(plane thro’ ASIS )- less common Two sagittal planes -midclavicular planes

12. Abdominal regions and their main contents

13. ANTERIOR ABDOMINAL WALL Is a musculo -aponeurotic structure confined to the anterior and lateral aspects of the abdomen. BOUNDERIES . SUPERIORLY- xiphoid process and the costal margin. INFERIORLY-ASIS, inguinal ligament ,pubic symphysis. LATERALY-sides of the abdomen ( i.e a line adjoining the lowest point of the thoracic cage and the highest point of the iliac crest ). Nb / • The anterior abdominal wall is firm and elastic. Its firmness protects the abdominal viscera and its elasticity allows the expansion of the abdominal viscera. • The posterior abdominal wall is osteomuscular and rigid and its rigidity provides support to the abdominal organs.

14. Boundaries of the abdominal wall

15. cont . .. It consists of 9 layers. From superficial to deep, these are: 1. Skin. 2. Superficial fascia. 3. Deep fascia 4 . External oblique muscle. 5 . Internal oblique muscle. 6 . Transversus abdominis muscle. 7 . Fascia transversalis. 8 . Extra peritoneal fat tissue. 9 . Parietal layer of peritoneum. N.B. The deep fascia is very thin (almost absent) in the anterior abdominal wall to allow the bulging/distension of the abdominal wall as after taking meals, during pregnancy, etc. It is also absent in the penis, scrotum, and perineum.

16. Fascial organization of the anterior abdominal wall

17. Umbilicus The umbilicus is the most obvious feature of the anterior abdominal wall. It is in fact a normal puckered scar in the anterior abdominal wall representing the site of attachment of the umbilical cord in the fetus.

18. Umbilicus cont… Position The position of umbilicus is variable: 1. In adult, it lies at the level of intervertebral disc between L3 and L4 vertebrae. 2. In newborn, it is slightly at a lower level due to poorly developed pelvic region. 3. In old age, it comes down to lower level due to diminished tone of the abdominal muscles.

19. Umbilicus cont… Anatomical Significance 1. The level of umbilicus serves as water-shed line for venous and lymphatic drainage. The venous blood and lymph, flow upward above the level of the umbilicus and downward below the level of the umbilicus. 2. It indicates the level of T10 dermatome, i.e., skin around the umbilicus is supplied by the 10th spinal segment. 3. It is one of the important sites of porto-caval anastomosis. 4.Site of attachment of umbilical cord during fetal life 5.Iits posterior surface is the meeting point of four peritoneal ligaments

20. Umbilicus cont… Although the umbilicus is a scar in the anterior abdominal wall, it is of immense cosmetic value particularly in the females. Therefore, the surgical incision should never be given across it. • The skin around the umbilicus is supplied by T10 spinal segment. Therefore, visceral pain of appendicitis is referred to the umbilicus (note the appendix is supplied b y T10 spinal segment).

21. McBurney’s Point It is a point at the junction of medial 2/3rd and lateral 1/3 rd of the line extending from the umbilicus to the anterior superior iliac spine . The base of appendix lies deep to this point. Murphy’s Point It is a point where linea semilunaris meets the right subcostal margin. It corresponds to the tip of the 9 th costal cartilage. The fundus of gall bladder lies deep to this point.

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23. Superficial fascia it is formed of a single layer of fatty tissue above the umbilicus and extends upwards. At the level of the umbilicus it has two layers The campers’ fascia ( superficial fatty layer) is the external layer that extends downward to bled with superficial fascia of the thighs. In the middle line it forms dartos fascia /muscle covering the scrotum and labia majora. NB/Over the penis, it is devoid of fat, and in the scrotum, it is replaced by an involuntary dartos muscle. The scarpa’s fascia ( deep membranous layer ) the internal layer that extends downwards and laterally into both lower limbs and in the middle to the perineum. -In the lower limbs it fuses with the fascia lata one inch below and parallel to the inguinal ligament. -it is prolonged over the penis to enclose it up to the base of the glans and forms the fascia of the penis (Buck’s fascia).

24. -it covers the scrotum where it is replaced by Colles ’ fascia -The Colles ’ fascia stretches across the margins of pubic arch and is attached to the posterior edge of posterior border of the perineal membrane, which also stretches across the pubic arch. -The space between the perineal membrane(superiorly) and Colles ’ fascia(inferiorly) is known as superficial perineal pouch. -The deep perineal pouch (A.K.A the deep perineal space) is an anatomical compartment within the pelvis.  It is located superior to perineal membrane and inferior to the pelvic diaphragm

25. Superficil fascia

26. Perineum in male and female Perineal membrane (in female)

27. Superior view of the pelvic diaphragm

28. Pelvic Diaphragm, Inferior View

29. Perineal membrane

30. Cut perineal membrane

31. Urogenital diaphragm (in male)

32. In the clinic…scarpas fascia (a) It serves as a firm unit for suturing the superficial fascia during closure of the anterior abdomen/perineum after abdominal or pelvic surgery. (b) The attachments of Scarpa’s and Colles ’ fasciae are such that they prevent the passage of extravasated urine due to urethral rupture backward into the ischiorectal fossae and downward into the thighs.

33. Spread of extravasated urine following rupture of membranous urethra

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35. ANTERIOR ABDOMINAL WALL MUSCLES

36. Anterior abdominal wall muscles Midline group: Rectus abdominis Piramidalis A nterolateral group: External oblique Internal oblique Transversus abdominis

37. Functions of the anterior abdominal muscles 1. To provide strong and expandable support for the abdominal viscera against gravity and protect them from injury. 2. To compress the abdominal contents to increase the intra-abdominal pressure and thus help in expulsive and expiratory acts. 3. To move the trunk to maintain the posture

38. External oblique: B -aponeurosis, A -fleshy part

39. Internal oblique

40. Rectus abdominis

41. MUSCLES OF ANTERIOR ABD. WALL SUPERFICIAL TO DEEP ; Ext.oblique ; origin: outer surfaces and lower borders of lower 8 ribs. Interdigitate with those of serratus ant. a nd lattismus dorsi . Insertion : posterior fibers to the anterior 2/3 of the iliac crest, middle fibers form the inguinal ligament while anterior ones meet those of the other side at the midline . Internal oblique ; Origin : Lateral 2/3 of the inguinal ligament, ant 2/3 of the iliac crest, thoracolumbar fascia. Insertion : lower 3 ribs, linear alba, conjoined tendon with the transversus abdominis. Transversus abdominis ; Origin: Lateral 1/3 of inguinal ligament ,anterior 2/3 of the inner lips of the iliac crest, thoracolumbar fascia. Internal aspects of the lower 6 costal cartilages Insertion : xiphoid process , linear alba, conjoint tendon

42. Structures derived from flat muscles The structures derived from flat muscles are as follows: Inguinal ligament. Conjoint tendon. Cremaster muscle . Inguinal Ligament It is the lower-free border of external oblique aponeurosis stretching between ASIS and pubic tubercle.

43. Cremaster Muscle : consists of a series of loops of skeletal muscle fibers joined by loose areolar tissue, the cremaster fascia. form the covering around the spermatic cord and testis. These muscle loops are derived from lower arched fibers of internal oblique. Function The contraction of cremaster muscle pulls the testis up toward the superficial inguinal ring, helps to plug the superficial inguinal ring . It also helps in controlling the temperature of the testis

44. Conjoint Tendon ( Falx Inguinalis ) It is formed by the fusion of lower aponeurotic fibers of internal oblique and transversus abdominis muscles which arches over the spermatic cord and is attached on to the pubic crest and medial part of the pectineal line. N.B. The weakening of conjoint tendon due to old age or injury of iliohypogastric and ilioinguinal nerves predisposes the occurrence of direct inguinal hernia.

45. Rectus sheath :Formation, ftns , contents The rectus sheath is an aponeurotic sheath enclosing the rectus abdominis muscle (and pyramidalis muscle if present)on either side of the linea alba. It is derived from the aponeuroses of flat muscles of the anterior abdominal wall.

46. Function of the rectus sheath (a) Checking the bowing of rectus abdominis muscle during its contraction and hence increasing its efficiency. (b) Maintaining the strength of the anterior abdominal wall.

47. Formation of the rectus sheath The formation of rectus sheath differs from above d ownward as follows: 1. Above the level of costal margin: (a) Anterior wall is formed by the aponeurosis of external oblique only. b)Posterior wall costal cartilages

48. 2. Between costal margin and arcuate line: (a) Anterior wall is formed by the fusion of aponeurosis of external oblique with the anterior lamina of aponeurosis of internal oblique. (b) Posterior wall is formed by the fusion of aponeurosis of transversus abdominis with the posterior lamina of aponeurosis of internal oblique.

49. 3. Below the level of arcuate line: (a) Anterior wall is formed by the aponeuroses of all the three flat muscles (the aponeuroses of transversus abdominis and internal oblique are fused but the aponeurosis of external oblique remains separate) (b) Posterior wall is deficient.

50. Transverse section showing formation of rectus sheath

51. Sagittal section of the anterior abdominal wall

52. Posterior wall of rectus sheath

53. Contents of rectus sheath 1. Two muscles: Rectus abdominis and pyramidalis (if present). 2. Two arteries: Superior epigastric and inferior epigastric. 3. Two veins: Superior epigastric and inferior epigastric. 4. Six nerves: Terminal parts of lower six thoracic nerves, including lower five intercostal nerves and subcostal nerve. (They are accompanied by terminal parts of posterior intercostal vessels.)

54. Contents of the rectus sheath

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56. Innervation of the anterior ab.wall - Nerves of the anterior abdominal wall can be divided into two groups lateral and anterior groups : The lateral group includes : the lower three intercostal nerves , the subcostal nerve , the iliohypogastric nerve (L1) and the ilioinguinal nerve (L1). The anterior group includes is the lower five intercostals nerves the subcostal nerve only. The 10 th nerve supplies the area around the umbilicus while the suprapubic area is supplied by the 12 th ( subcostal ) nerve NERVES SUMMARY Lower 5 intercostals. Sub costal Iliohypogastric (LI) Ilioinguinal .(L1)

57. Cutaneous innervation of the anterior abdominal wall Sourced from the lower five intercostal nerves(T7-T11 and subcostal nerve-T12) and the L1( iliohypogastric and ilioinguinal nerves)

58. Schematic arrangement of a typical abdominal nerve

59. Lower intercostal nerves and abdominal nerves

60. Nerve blocs in lower abdomen

61. Dermatomes of the anterior abdominal wall

62. Course of ilioinguinal and iliohypogastric nerve

63. Blood supply and lymphatics . BLOOD VESSELS; From up Superior epigastric arteries & musculophrenic a. Lower 5 posterior intercostal arteries Sub costal artery. From below i )External iliac artery gives Inferior epigastric artery which anastomoses with superior epigastric A. in mid abd . deep circumflex iliac vessels ii)Superficial branches of femoral artery( superficial inferior epigastric artery, superficial external pudendal , superficial circumflex iliac vessels ). Ascend superficial to the inguinal ring to supply the ant. Abd wall iii)Deep branch of femoral artery- deep external pudendal artery

64. Arterial supply to the anterior abdominal wall

65. VEINS Above umbilicus superficial epigastric drains into internal thoracic vein – brachio - cephalic vein . The posterior intercostal veins accompany the arteries and terminate superiorly into the azygos vein which ends in the superior vena cava . Umbilical level Para umbilical veins drains into liver Below umbilicus Inferiorly superficial veins drain into the great saphenous vein and femoral vein ending finally into the inferior vena cava. So, they connect the superior with inferior vena cava while deep veins drain in to external iliac vein.

66. LYMPHATIC DRAINAGE: Superficial lymphatics Above umbilicus - into axillary lymph nodes(anterior group). Below umbilicus- superficial inguinal lymph nodes. Around umbilicus-to LN of porta hepatis of liver along the ligamentum teres hepatis Deep lympatics Above umbilicus : parasternal LN (lie along internal thoracic a.) Below umbilicus : drain into external iliac LN

67. Lymphatic drainage of the anterior abdominal wall

68. INGUINAL CANAL

69. The Inguinal Canal This is an oblique passage through the lower part of the anterior abdominal wall. In the males , it allows structures to pass to and from the testis to the abdomen and in females it allows the round ligament of the uterus to pass from the uterus to the labium majus . It is about 1.5 in. (4 cm) long in the adult and extends from the deep inguinal ring , a hole in the fascia transversalis , downward and medially to the superficial inguinal ring, a hole in the aponeurosis of the external oblique muscle It lies parallel to and immediately above the inguinal ligament. In the newborn child , the deep ring lies almost directly posterior to the superficial ring so that the canal is considerably shorter at this age. Later, as the result of growth, the deep ring moves laterally.

70. The deep and superficial rings The deep inguinal ring: is an oval opening in the fascia transversalis, lies about 0.5 in. (1.3 cm) above the inguinal ligament midway between the anterior superior iliac spine and the symphysis pubis Related to it medially are the inferior epigastric vessels. The margins of the ring give attachment to the internal spermatic fascia (or the internal covering of the round ligament of the uterus). The superficial inguinal ring: is a triangular-shaped defect in the aponeurosis of the external oblique muscle and lies immediately above and medial to the pubic tubercle NB> The margins of the ring, sometimes called the crura , give attachment to the external spermatic fascia

71. Wall of the inguinal canal Anterior wall : External oblique aponeurosis , reinforced laterally by the origin of the internal oblique from the inguinal ligament. This wall is strongest where it lies opposite the weakest part of the posterior wall, namely, the deep inguinal ring. Posterior wall: Conjoint tendon medially, fascia transversalis laterally . This wall is strongest where it lies opposite the weakest part of the anterior wall, namely, the superficial inguinal ring. Roof or superior wall: Arching lowest fibers of the internal oblique and transversus abdominis muscles Floor or inferior wall: Upturned lower edge of the inguinal ligament and at its medial end, the lacunar ligament

72. The Inguinal canal

73. Scrotal layers

74. Mechanisms of maintaining the canal the canal is an oblique passage with the weakest areas, namely, the superficial and deep rings, lying some distance apart except in the newborn infant, therefore when intra- abd pressure increases the ant. & post. wall of the canal approximate obliterating the passage(flap valve mechanism). The anterior wall of the canal is reinforced by the fibers of the internal oblique muscle immediately in front of the deep ring. The posterior wall of the canal is reinforced by the strong conjoint tendon immediately behind the superficial ring. On coughing and straining, as in micturition, defecation, and parturition, the arching lowest fibers of the internal oblique and transversus abdominis muscles contract, flattening out the arched roof so that it is lowered toward the floor .(shutter mechanism). When great straining efforts may be necessary, as in defecation and parturition, the person naturally tends to assume the squatting position ; the hip joints are flexed, and the anterior surfaces of the thighs are brought up against the anterior abdominal wall. By this means, the lower part of the anterior abdominal wall is protected by the thighs

75. Spermatic Cord collection of structures that pass to and from testis through the inguinal canal . It extends from the deep inguinal ring to the posterior border of the testis and is covered by three fascial layers. Consists of the following six groups of structures: 1. Ductus deferens 2 . Three arteries: Testicular artery Cremasteric artery , from inferior epigastric artery. Artery to ductus deferens(artery of vas) from inferior vesical artery. 3. Veins- the pampiniform venous plexus, testicular vein. 4 . Lymphatics 5 . Nerves: genital branch of genitofemoral nerve( cremasteric n.) and sympathetic fibres which accompany the arteries . 6. Remains of processus vaginalis

76. Coverings of the spermatic cord is covered by three fascial layers from within outward, these are: Internal spermatic fascia -derived from fascia transversalis. Cremasteric fascia- The muscle fibers are derived from internal oblique muscle. External spermatic fascia -derived from aponeurosis of external oblique muscle.

77. Structures passing through the deep and superficial inguinal rings

78. Fascia transversalis Lines transversus abdominis m. Opening: - the deep inguinal ring lies 1/2in above mid inguinal point - it lies just lateral to the inf. Epigastric a. & below the arching fibres of transversus abdominis m. Prolongations of the fascia: Internal spermatic fascia & anterior wall of the femoral sheath

79. Extensions of the fascia transversalis Anteriorly : Continuous with the fellow of the opposite side & adherent to linear alba Superiorly: continuous with the diaphragmatic fascia lining the lower surface of the diaphragm Posteriorly: Continuous with the renal fascia Inferiorly: attached to inner lip of the iliac crest & inguinal lig . (laterally), over the external surface of the external iliac vessels, it sends a downward prolongation into the thigh forming the ant. wall of the rectus sheath, medial to the external iliac vessels its attached to the pectineal line & pubic crest

80. Folds in the internal surface of abdominal wall The median umbilical fold : it extends from the apex of the urinary bladder to the umbilicus and covers the median umbilical ligament, the remnant of the urachus , which joined the apex of the fetal bladder to the umbilicus. Two medial umbilical folds , lateral to the median umbilical fold, cover the medial umbilical ligaments, formed by occluded parts of the umbilical arteries. Two lateral umbilical folds : they are lateral to the medial umbilical folds, cover the inferior epigastric vessels and therefore bleed if cut.

81. The fossa on the abdominal wall Supravesical fossae :- lies between the median and the medial umbilical folds, formed as the peritoneum reflects from the anterior abdominal wall onto the bladder. The level of the supravesical fossae rises and falls with filling and emptying of the bladder. Medial inguinal fossae :- between the medial and the lateral umbilical folds, areas also commonly called inguinal triangles ( Hesselbach triangles), which are potential sites for the less common direct inguinal hernias. Lateral inguinal fossae :- lateral to the lateral umbilical folds, include the deep inguinal rings and are potential sites for the most common type of hernia in the lower abdominal wall, the indirect inguinal hernia.

82. Boundaries of hesselbach’s triangle Inferior : inguinal ligament Medially : lateral border of rectus abdominis Laterally : inferior epigastric vessels

83. Application

84. Hernia Defn : an abnormal protrusion of any abdominal viscera thro’ a weak part of the abd.wall e.g loop of the small intestine, greater omentum …… Two conditions must exist for it to occur: presence of defect in the abd . Wall & increase in intra abd . Pressure Structure : sac, covering & content Parts : neck, body & fundus

85. Direct-vs-Indirect Leaves the abdominal cavity through the deep inguinal ring with structures of the spermatic cord Often extends in to scrotum/ labia majus Some may be due to patent processus vaginalis Enters lateral to ’ Hasselbach's triangle Neck is usually small Lateral to inferior epigastric artery Occurs in young age Sometimes reducible Piriform(elongated) in shape Enters inguinal canal directly through a weakness/defect in the posterior wall Rarely extends to scrotum Due to weakness of anterior abd . wall Enter through thro’ Hasselbach's triangle Neck is usually large. The hernia is globular Medial to inferior epigastric artery Occurs in middle and old age Always reducible Globular in shape Direct Indirect

86. Inguinal vs femoral hernias

87. Inguinal vs femoral hernia

88. Umbilical hernia

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