Part 1: Body Wall

Question 1

Describe the role of scarpa’s fascia in the body wall and ts margins in the thorax

Answer 1

Superficial membranous fascia that allows fatty subcut layer to slide freely over thoracic wall. Fades out over upper thoracic wall and along mid axillary lines. Below thighs it is attached to fascia lata at hip flexor crease

Question 2

What is the blood supply to the thoracic wall?

Answer 2

Intercostals and lumbar arteries pass forward in neurovascular (Between middle and innermost muscle layers) plane to supply flanks.
Ventral midline tissue is supplied by internal thoracic, superior epigastric and inferior epigastric with cutaneous branches

Question 3

What is the venous drainage of the body wall?

Answer 3

Does not follow arteries. Network veins radiating away from umbilicus. Below umbilicus they run to great saphenous in groin, above to lateral thoracic vein and to axillary vein. Some drain to ligamentum teres which drains into portal vein

Question 4

Describe the lymph drainage of the body wall

Answer 4

Above umbilicus - anterior to pectoral nodes, posterior to scapular nodes
Below umbilicus - anterior to medial superficial inguinal, lateral to lateral inguinal nodes

Question 5

What is the nerve supply of the body wall

Answer 5

Above 2nd rib is by supraclavicular branches of cervical plexus.
Below this - midline - anterior cutaneous nerve (spinal nerves T2-L1)
Broad lateral strip by lateral cutaneous nerves (T2/3-L1)
Posterior strip - posterior rami of spinal nerves - medial fibres upper part, lateral fibres lower part

Question 6

What are the muscles layers of the body wall?

Answer 6

Outer
Middle/Inner
Innermost

All derived from mesoderm, dorsal becomes erector spinae and anterior develops the 3 layers

Question 7

What muscles make up outer layer?

Answer 7

External intercostals, serratus posterior, external obliques, scalenus posterior

Question 8

What are the muscles of the inner/middle layer?

Answer 8

Internal intercostals, internal obliques, scalenus medius

Question 9

What are the muscles of the innermost layer?

Answer 9

Transversus thoracis group (Innermost intercostals, transversus thoracis, subcostals, diaphragm)
Transversus abdominus, quadratus lumborum, lavator ani