Abdomen and peritoneal anatomy

Question 1

What are the boundaries of the abdomen?

Answer 1

Superior- Diaphragm, inferior thoracic aperture
Inferior- Iliac crest, inguinal ligament, pelvic inlet.
Posterior- Lumbar vertebral column, Psoas major, quadrates lamborum, abdominal wall muscles
Lateral and anterior- abdominal wall

Question 2

Nine divisions of the abdomen

Answer 2

Left and right hypochondrium
Epigastric
Left and right flank
Umbilical
Left and right groin
Pubic region

Question 3

Layers of the abdomen from most superficial.

Answer 3

Epidermis
Superficial fascia: Campers and scarpas (only below umbilicus)
Muscles: External oblique, internal oblique, transverse abdominis
Trasversalis fascia
Extraperitoneal fascia
Parietal peritoneum

Question 4

Rectus abdominas: Name origin, insertion, action and nerve

Answer 4

Origin- pubic symphysis, pubic tubercle, pubic crest
Insertion, xiphoid process, lower cartilage of ribs
Action: Flex trunk, Support abdo cavity
Nerve: Anterior rami of thoracic spinal nerves

Question 5

External oblique: Name origin, insertion, action, nerve and fibre direction

Answer 5

Origin: Ribs 5-12
Insertion: Iliac crest and linea alba
Action: turn to opposite side
Nerve: anterior rami of thoracic spinal nerves
Fibre direction: Inferior-medial

Question 6

Internal oblique: Name origin, insertion, action, nerve and fibre direction

Answer 6

Origin: Inguinal ligament, iliac crest, thoracolumbar fascia
Insertion: Ribs 9-12
Action: turn to same side
Fibre direction: Supero medial
Nerve: Anterior rami of thoracic spinal nerves

Question 7

Transverse abdominas: Name origin, insertion, action, nerve and fibre direction

Answer 7

Origin: Thoracolumbar fascia, iliac crest, inguinal ligament
Insertion: linea alba, pectineal line, pubic crest
Action: supports abdominal wall
Nerve:Anterior rami of thoracic spinal nerves
Fibre direction: transverse

Question 8

Rectus sheath- describe.

Answer 8

Aponeurosis of three abdominal wall layers, completely enclose the rectus abdominas to the level of the arcuate line where it covers the superficial surface only.

Question 9

Abdominal muscle blood supply

Answer 9

Inferior and superior epigastric arteries. They enastamose and run over the top of the transversalis fascia.

Question 10

Venous drainage

Answer 10

Thoracoepigastic- drains to axillary

Superficial epigastric- drains to femoral

Question 11

Nerve supply and pathway

Answer 11

Skin, muscle and parietal peritoneum all supplied by lower 6 (T7-12) intercostal nerve and iliohypogastric/ ilioinguinal (L1). All from anterior rami
Nerves travel between internal oblique and transversus abdominal

Question 12

Abdomen dermatomes start, middle finish

Answer 12

T6 at xiphoid proces, T7, T8, T9, T10 at umbilicus, T11, T12, L1 at anterior rami of pubic symphysis

Question 13

Lymphatic drainage

Answer 13

Above bellybutton anterior and posterior auxiliary

Belo bellybutton the superficial inguinal

Question 14

Describe the nerve supply of the parietal peritoneum

Answer 14

SOMATIC
Sensitive to touch, pain, pressure, temperature.
Body wall- thoracic and lumbar nerves
Superior- phrenic nerve
Inferior- obturator nerve

Question 15

Describe the neve supply to the visceral peritoneum

Answer 15

AUTONOMIC
Sensitive to stretch/ distension
Afferent fibres