1. STUDY OF HUMAN ANATOMY

2. ANATOMY OF THE ABDOMEN

3. A region of the body bounded by the following regions:-
DEFINITION OF ABDOMEN
A region of the body bounded by the following regions:-
Superiorly – thorax
Inferiorly – pelvis/perineum
Posteroinferiorly – back
Inferolaterally – lower limbs

4. BONY LANDMARKS OF THE ABDOMEN
Xiphoid process
Costal margin – 7th – 11th costal cartilages
Pelvic bones
L1 – L5 Lumbar vertebrae

5. ABDOMINAL CAVITY
extends btw thoracic diaphragm & pelvic diaphragm – abdominopelvic cavity
upper part is under cover of the osteocartilagenous thoracic cage
occupied by organs of the digestive, urogenital, endocrine & vascular structures.

6. CONTENTS OF THE ABDOMINAL CAVITY

7. CONTENTS OF THE ABDOMINAL CAVITY

8. ABDOMINAL WALL

9. PLANES OF THE ABDOMEN
4 planes divide the abdominal cavity into 9 regions
2 vertical (midclavicular), midclavicular to midinguinal
2 transverse – ( subcostal & transtubercular)
Subcostal – pass through 10th costal cartilage
Transtubercular – pass through iliac tubercle

10. REGIONS OF THE ABDOMEN

11. REGIONS OF THE ABDOMEN

12. QUADRANTS OF THE ABDOMEN
2 planes delineate the abdominal cavity into 4 quadrants
1 vertical – median
1 transverse – transumbilical

13. POSITIONS OF THE ABDOMINAL ORGANS

14. ANTEROLATERAL ABDOMINAL WALL
Anterior & lateral walls extending from the thorax to pelvis
Consists of the
(1) Skin
(2) Fascia - Subcutaneous & deep
(3) Muscles
(4) Transversalis fascia
(5) Extraperitoenal fat
(6) Peritoneum

15. ANTEROLATERAL ABDOMINAL WALL
Anterior & lateral walls extending from the thorax to pelvis
Consists of the
(1) Skin
(2) Fascia - Subcutaneous & deep
(3) Muscles
(4) Transversalis fascia
(5) Extraperitoenal fat
(6) Peritoneum

16. SKIN
Loosely attaches to the superficial fascia, except at the umbilicus.
Varies in texture - wrinkle, rough, smooth, scars.
Thin in front and thick at the back
Distribution of hair varies with sex, age and race.
Natural tension lines run horizontally around the body wall.

17. FASCIA
(L. panniculi – apron)
Composed of fatty tissues and fibrous connective tissue
Divided into two layers
(1) Superficial
(2) Deep – covers abdominal muscles
(1) Same as elsewhere and varies in amount of fat.
(1) Major site of fat storage.
(1) Excessive fat deposition in the lower anterior abdominal wall – morbid obesity

18. SUPERFICILA FASCIA/TISSUE
Superior to umbilicus
Consistent with other regions
Inferior to umbilicus
Reinforced by collagen and elastic fibers
Thus 2 layers –
(1) Superficial fatty layer (Camper’s fascia)
Same elsewhere
(2) Deep membranous layer (Scarpa’s fascia)
Membranous continues to the perineum – Colles’s fascia, not to the thigh.

19. SUPERFICIAL FASCIA

20. SUPERFICIAL FASCIA

21. MUSCLES OF THE ANTEROLATERAL ABDOMINAL WALL
5 pairs of muscles bilaterally – 3 flat, 2 vertical
(1) External oblique
(2) Internal oblique
(3) Transversus abdominis
(4) Rectus abdominis
(5) Pyramidalis

22. EXTERNAL OBLIQUE MUSCLE
O: external surfaces of 5th – 12th ribs
I: linea alba, pubic tubercle, ant ½ of iliac crest
N: thoracoabdominal nerves (T7-T11 spinal nerves), subcostal nerve.
A: compresses the abdomen to provide support for abdominal organs.

23. INTERNAL OBLIQUE MUSCLE
O: thoracolumbar fascia, ant 2/3 of iliac crest, lat 1/3 of inguinal ligament.
I: inferior borders of 10th – 12th ribs, linea alba, pecten pubis, conjoint tendon.
N: thoracoabdominal nerves (T6-T12 spinal nerves), L1 nerve
A: compresses and supports abdominal viscera

24. TRANSVERSUS ABDOMINIS MUSCLE
O: thoracolumbar fascia, internal surfaces of 7th-12th costal cartilages, iliac crest, lat 1/3 of inguinal ligament.
I: linea alba, pubic crest, pecten pubis, conjoint tendon.
N: thoracoabdominal nerves (T6-T12 anterior rami of spinal nerves), L1 nerve
A: compresses and supports abdominal viscera

25. RECTUS ABDOMINIS MUSCLE
O: pubic symphysis & pubic crest
I: xiphoid process & 5th-7th costal cartilages
N: thoracoabdominal nerves (T6-T12 spinal nerves)
A: flexes trunk, compresses and supports abdominal organs, prevents pelvic tilting

26. ABDOMINAL MUSCLES

27. ABDOMINAL MUSCLES

28. DEEP FASCIA
Dense connective tissue layer , devoid of fat, that covers the muscles and their aponeurosis.
3 layers – superficial, intermediate & deep.

29. DEEP FASCIA

30. PYRAMIDALIS MUSCLE
Small, insignificant muscle.
Absent in 20% of people
O: pubic crest, pubic symphysis
I: linea alba
N: subcostal nerve (T12)
A: tenses the abdomen

31. RECTUS SHEATH
A strong incomplete fibrous compartment
Formed by decussation and interweaving of the flat abdominal muscles.
Internal oblique aponeurosis splits into two layers: anterior & posterior and invest the rectus abdominis muscle.

32. RECTUS SHEATH
Anterior wall – external oblique, anterior layer of internal oblique
Posterior wall – transversus abdominis and posterior layer of internal oblique.
All aponeuroses fuse in the midline – linea alba.
In the midline, it contains the umbilical ring. A defect where fetal umbilical vessels pass to the placenta.
Splitting of internal oblique, lateral to rectus abdominis – semilunar line.

33. RECTUS SHEATH
Posterior wall ends slightly below the umbilicus – arcuate line of Douglas.
The rectus abdominis is covered by the transversalis fascia posteriorly.

35. CONTENTS OF THE RECTUS SHEATH
Rectus abdominis muscle
Pyramidalis
Superior & inferior epigastric vessels
Intercostal nerves (T7-T11)

36. RECTUS SHEATH

37. ENDOABDOMINAL FASCIA
A membranous and areolar sheets.
Named according to muscle or aponeurosis it lines.
Transversalis fascia as it lines the transversus abdominis muscle.
A variable amount of fat separates the fascia above from the peritoneum – extraperitoneal fat.
Peritoneum – a single layer of epithelial cells and connective tissue.

38. NERVES OF THE ANTEROLATERAL ABDOMINAL WALL
(1) thoracoabdominal nerves (T7 – T11)
(2) Subcostal nerve (anterior ramus of T12)
(3) Iliohypogastric
(4) Ilioinguinal

39. VESSELS OF THE ANTEROLATERAL ABDOMINAL WALL
(1) superior epigastric artery
(2) musculophrenic artery
(3) 10th & 11th post intercostal arteries
(4) subcostal artery
(5) inferior epigastric
(6) deep circumflex iliac
(7) superficial circumflex iliac
(8) superficial epigastric

40. VEINS & LYMPHATICS OF THE ANTEROLATERAL ABDOMINAL WALL
(1) Subcutaneous venous plexus
(2) Paraumbilical veins
(3) Lateral thoracic vein
(4) Superficial epigastric veins
(5) superficial circumflex iliac
(6) superior & inferior epigastric
(7) deep circumflex iliac
(8) posterior interocstal (11th) & subcostal veins

41. FUNCTIONS OF THE ABDOMINAL MUSCLES
Form a strong expandible support for the wall
Support organs from injuries
Compress to increase intraabdominal pressure to facilitate expulsion
Move trunk to maintain posture
Assists in breathing

42. FINIS