Flashcards in Anatomy of the Abdominal Wall, Inguinal Region and Hernias Deck (61)
What are the bony landmarks of the abdomen?
Sternum and xiphoid process
Costal margin, costal cartilages and ribs
Iliac crest, iliac fossa and anterior superior iliac spine (ASIS)
Pubic symphysis, pubic tubercle and pubic ramus
Thoracic and lumbar vertebrae, sacrum and pelvic bones
What visceral structures are found in the abdomen?
Stomach, duodenum and small intestines
Liver, pancreas and spleen
Kidneys, ureters and urinary bladder
What are the 9 regions that the abdomen can be divided into (from top right to bottom left)?
Right hypochondriac, epigastric, left hypochondriac
Right lumbar, umbilical, left lumbar
Right iliac, hypogastric/suprapubic, left iliac
What are the two fascia found immediately below the skin and what are their characteristics?
Camper's Fascia - fatty fascia
Scarpa's Fascia - membranous layer
What muscles make up the posterior wall of the abdomen?
Quadratus lumborum, psoas major and iliacus muscles
Post-vertebral muscles (erector spinae group)
What muscles make up the lateral wall of the abdomen?
What muscles make up the anterior wall of the abdomen?
The paired vertical rectus abdominal muscles within the rectus sheath.
What is an aponeurosis?
Thin but strong fibrous sheet of tissue that replaces a tendon in muscles that are flat and sheet-like and have a wide area of attachment.
What are some functions of the three sheet-like muscles?
Compresses the abdomen and increases intra-abdominal pressure to aid expiration and evacuation of faeces, urine and parturition, heavy lifting.
Supports viscera - guards the intestines
Flex and rotate the trunk
What are the attachments of the external oblique?
External surfaces of the bottom 8 ribs
Free posterior border
Xiphoid process, linea alba, pubic crest and tubercle, anterior 1/2 of the iliac crest
State the direction of the external oblique muscle fibres.
How is the inguinal ligament made and where does it attach?
Formed by the rolling inwards of the lower aponeurotic border of the external oblique. It extends from the anterior superior iliac spine (ASIS) to the pubic tubercle
What are the attachments of the internal oblique?
Laterally: thoracolumbar fascia, anterior 2/3 of iliac crest, lateral 1/2 of inguinal ligament
Medially: lower 3 ribs and costal cartilages, xiphoid process, rectus sheath and conjoint tendon
State the direction of the muscle fibres of the internal oblique.
What are the attachments of the transversus abdominis?
Laterally: bottom 6 costal cartilages, thoracolumbar fascia, anterior 2/3 of the iliac crest, lateral 1/3 of the inguinal ligament
Medially: xiphoid process, linea alba, pubic symphysis, conjoint tendon
State the direction of the muscle fibres of the transversus abdominis.
Where does the neurovascular layer lie?
Between the internal oblique and the transversus abdominis
What are the points of attachment of the rectus abdominis?
5-7 costal cartilages, xiphoid process
Pubic symphysis, pubic crest
What structures divide the rectus abdominis into segments?
Transverse tendinous intersections
What is the rectus sheath formed by?
The aponeuroses of the three flat muscles.
Describe the arrangement of the rectus sheath above and below the arcuate line.
Above the arcuate line - the internal oblique splits to encase the rectus abdominis. The external oblique is anterior to the rectus sheath and the transversus abdominis is posterior to the rectus abdominis.
Below the arcuate line - all three sheet muscles are anterior to the rectus abdominis. The posterior surface of rectus abdominis is in contact with the transversalis fascia.
What is the function of the rectus abdominis?
It is a powerful flexor of the vertebral column.
What are the points of attachment of quadratus lumborum?
Lower border of the 12th rib
Transverse process of lumbar vertebra 5
Adjacent iliac crest
What are the points of attachment of psoas major?
Bodies of all five lumbar vertebra
Lesser trochanter of the femur
What plane carries the nervous and blood supply to the abdominal wall?
Neurovascular plane - found in between the internal oblique and the transversus abdominis
Describe the blood supply to the rectus sheath.
Superiorly, blood supply comes from the superior epigastric artery, which is the terminal branch of the internal thoracic artery.
Inferiorly, blood supply comes from the inferior epigastric artery, which is a branch of the external iliac artery.
The two vessels anastomose providing a potential by-pass of the abdominal aorta.
Which vessels supply the flank muscles?
Intercostal arteries 7-11
Deep circumflex iliac artery
What nerves supply the abdominal wall?
What nerves supply the external oblique, internal oblique and transversus abdominis?
External Oblique - T7-T11
Internal Oblique - T7-L1
Transversus Abdominis - T7-L1