127. Abd Wall, Hernia

Question 1

What are the 4 layers of the superficial body wall and the 5 layers of the deep body wall?

Answer 1

Epidermis, Dermis, Superficial Fascia, Scarpa’s Fascia (only lower abd wall to handle extra pressure)

Deep/Investing Fascia, Muscle, Bone, Transversalis Fascia (only lower abd wall), Parietal Peritoneum

Question 2

What are the connections of the inguinal ligament? What features run above and below the inguinal ligament?

Answer 2

From ASIS to pubic tubercle

Below: femoral vessels
Above: inguinal region

Question 3

What are the muscles, their fiber arrangement, and functions of the anterior abdominal wall? (Four muscles)

Answer 3

1. Rectus abdominus - vertical fibers - flex trunk
2. External Oblique - inf/medial fibers - flex trunk, ipsi lat bend, contra rotation
3. Internal Oblique - inf/lateral fibers - flex trunk, ipsi lat bend, ipsi rotation
4. Transversus Abdominus - horizontal fibers (no movement)

All muscle fx: increase intra-abd pressure (posture, vomit, childbirth, cough, laugh, defecation), stabilize pelvis for leg muscle fx, lower rib cage and raise diaphragm for exhaling

Question 4

What is the difference between the upper and lower parts of the sheath of rectus abdominus? What feature marks the switch between upper and lower sheath?

Answer 4

Upper: External Oblique aponeurosis anterior to rectus abdominus, Internal Oblique apo divides around rectus abd, Transversus abd posterior to rectus abd

Lower: All 3 pass anterior to rectus abd

Arcuate Line: termination of posterior sheath (below line, rectus abd runs on transversalis fascia and parietal peritoneum), deep inferior epigastric artery enders deep abd wall passing below arcuate line under rectus abd

Question 5

Formation of the Inguinal Canal (male)

Describe the derivates of abd wall layers that make up parts of the scrotum

Answer 5

Development: testes must pass through deep body wall to scrotum, forming inguinal canal during descent
Gubernaculum: connects testes to scrotum
Spermatic Cord: ductus deferens and testicular vessels/nerves/lymphatics

Parietal Peritoneum - Processus Vaginalis (obliterates)
Transversalis Fascia - Deep inguinal ring, internal spermatic fascia
Transversus Abdominus (no component, conjoint tendon)
Internal Oblique - cremaster muscle (elevates testes)
External Oblique - superficial inguinal ring and external spermatic fascia
Scarpa’s fascia - Colle’s Fascia lining scrotal sac
Superficial (Camper’s) Fascia - dartos muscle/fascia (thin smooth muscle too keep testes uninsulated/cool)

Question 6

Inguinal Canal in females
How does the gubernaculum persist?
What is filled in the inguinal canal?

What is the start and end of the inguinal canal?
What is the conjoint tendon?

Answer 6

Ovary descends from deep abd wall but stops at pelvis
Gubernaculum - 1. Ovarian Ligament (ovary to uterus), 2. Round ligament of uterus (connects uterus to inguinal canal)
inguinal canal full of “finger of fat”

Start: deep ring (evagination of transversalis fascia)
End: superficial ring (from external oblique)

Conjoint tendon: internal oblique and transversus muscle combine, attach to inguinal ligament

Question 7

What 3 landmarks make up the inguinal triangle?

What is the difference between indirect inguinal hernia and direct inguinal hernia?

Answer 7

Triangle: lateral edge of rectus m., inferior epigastric artery, inguinal ligament

Indirect: most congenital, through inguinal canal and deep ring (in spermatic cord), LATERAL to inf epigastric artery (newborn: patent processus vaginalis)

Direct: NOT through inguinal canal, medial to inferior epigastic artery, origin: under conjoint tendon, medial to inguinal canal