The abdomen is a cylindrical cavity bounded superiorly by the thoracic aperture and inferiorly by the pelvic inlet. It houses the major organs of the gastrointestinal system, spleen, and urinary organs. The abdominal wall consists of bone (lumbar vertebrae and pelvic bones) and muscles. It has four quadrants divided by a horizontal plane through the umbilicus and a vertical midline plane. The abdominal cavity is lined by two layers of peritoneum and contains both intraperitoneal and retroperitoneal organs. The abdominal muscles assist with breathing by relaxing on inspiration and contracting on expiration.

1. Abdomen

2. Coceptual overview
• Cylendrical
• Inferior thoracic aperture is the superior opening of the abdomen
• Inferiorly it is continuous with pelvic inlet
• Chamber enclosed by peritoneal cavity
• Inferior limit of abdomen is superficial margin of lower limb

3. function
• Houses major elements of gastrointestinal system , spleen,and
urinary etc
• Protection by wall
• Kidney superior poles are protected in lower ribs
• Vicera is supported by the muscles of the abdomen
• Liver, stomach, spleen, gallbladder comes in dome of the diaphragm

5. Breathing
• Imp role of abdominal wall is to assist in breathing
• In inspiration abdmenal muscles is relaxed and diaphragm is
contracted
• In expiration abdominal muscles contracted and diaphragm relaxes
• Forceful expiration like coughing and sneezing is due to the abd
muscles
• Intra abdominal pressure assist in voiding the contents of bladder and
rectum and in giving child birth

7. Components of abd
WALL
• The abd wall consist partly of bone and mainly of muscles
The skeletal elements are,,
• Five lumbar vertebra and their intervertebral discs
• Superior part of the pelvic bones
• Bony component of inferior thoracic wall including costal margin
• Muscles makes the rest of the walls

9. Abdominal cavity
• Abdominal cavity is lined by peritoneum
having 2 parts
parietal peritoneum > covers the abdominal walls
visceral peritoneum > covers the suspended organs
• Abdomenal vicera are either intraperitoneal or retroperitoneal
• Intraperitoneal >
• Retro peritoneal >

11. Four qujadrant
• A horizontal transumbilical plane passing through the umbilicusand
the intervertebral disc between the intervertebral l3 and l4
• A vertical intersection divides it in right and left parts
• 4 quadrants are made
• Right upper, left upper, right lower , left lower

12. Nine regions
• Two horizontal and two vertical
• Superior horizpntal (plane subcostal) is inferior to the 10th rib
• Posterior > l3
• Inferior horizontal plane ( intertubercal plane) connects the iliac crest

14. Abdominal wall
• Covers large area
• Superiorly by xiphoid process, costal margins
• Inferiorly by upper parts of the pelvic bone
• Layers consists of skin, super facial facia ( subcutaneous facia), deep
facia,muscle , extra peritoneal facia and parietal peritoneum

16. skin
• Loosely attached except umbilicus
• Lines of cleavage runs downwards
• Umbilicus present in the linia alba
• Incisions along the cleavage line heal as a narrow scar

18. Super facial fascia
• Divided into
• Superficial fatty layer and
• Deep membranous layer
• Fatty layer is extreem;ly thick up to 3 inches or 8 cm
• Inferior it fuses with thigh belwo the inguinal ligament
• Inferiorly passed through the wall of scrotum , each side of the pubic
arch and make colles fascia
• Superficial fascia in scrotum is a thin smooth muscle dartos muscle