1: Anterior Abdominal Wall Flashcards
Two boundaries of the abdominopelvic cavities
Thoracic diaphragm + pelvic diaphragm
Pelvic inlet
Separates abdomen + pelvis
Direction the EO, IO, and TA run
EO: downward and medial
IO: 90 degrees from EO
TA: transverse and medial, some runs towards pubic crest
EO O and I
O: outer lower 7 ribs
I: aponeuroses, linea alba, anterior iliac crest, pubic tubercle
EO N
Ventral rami T7-12 of intercostal N’s
EO action
Compresses abdomen to increase intra-abdominal pressure, moves trunk, retains posture
Three things formed by the external oblique
- Inguinal ligament: from lower portion
- Inguinal ring
- Lacunae ligament
What does the EO interdigitate with?
Serratus anterior
Internal Oblique O and I
O; iliac crest, thoracolumbar fascia
I: lower 10-12 ribs, aponeuroses, linea alba, pubic crest
IO N
T7-12, L1
Internal Oblique action
Compresses and supports viscera, lateral flexion, rotation
Two things formed by the IO
Inguinal falx, cremasteric muscle (part of it)
Transversus Abdominis O and I
O: lower 7-12 ribs, thoracolumbar fascia, iliac crest, upper inguinal lig
I: linea alba, pubic crest
Transversus abdominis N
T7-L1
Transversus abdominis action
Compresses and supports viscera
What does the transversus abdominis contribute to in the inguinal region?
Inguinal falx
Rectus abdominis O and I
O: pubic symphysis, pubic crest
I: xiphoid process, outer surface of intercostal cartilages 5-7
Rectus abdominis N
Ventral rami T7-12
Rectus abdominis action
Flexes and compresses abdomen
Linea semilunaris
Lateral border of rectus abdominis
Pyramidis M
Quite small in pubic region, missing in 20% of people
Rectus sheath
Fascia and aponeuroses of the abdominal muscles that encompasses the rectus abdominis M
Where are RA tendinous intersections? Three levels
Umbilical, xiphoid, and midway levels
Which aponeurosis is always anterior?
EO
IO aponeurosis
Splits to encompass rectus muscle in upper 3/4ths, lower 1/4 is all anterior
Arcuate line
Sharp transition between where all EO, IO and TA aponeuroses become anterior to rectus abdominis
Three folds on the internal anterior abdominal surface and what they form from
- Median umbilical fold: obliterated urachus
- Medial umbilical fold: obliterated umbilical A’s
- Lateral umbilical fold: inferior epigastric A
2 nerves that traverse the inguinal canal
Ilioinguinal, genitofemoral N
What arteries runs along the inguinal lig
Superficial circumflex iliac A, deep circumflex iliac A
What muscle does the inferior epigastric A run posterior to?
Rectus abdominis
Superficial lymph vessels: superior and inferior to umbilicus drain into what?
Superior -> axillary nodes
Inferior -> superficial inguinal nodes
Where are deep lymph vessels in the anterior abdomen
Accompany deep veins of abdominal wall (external and internal iliacs)
Iliopubic tract
Thickened transversalis fascia posterior to inguinal lig, reinforces floor of inguinal canal
Direct vs indirect hernia location
Direct: through inguinal canal
Indirect: through deep inguinal ring
What herniates in an inguinal hernia?
Peritoneum/transversalis fascia, spermatic cord
Femoral hernia location
Below inguinal ligament
Demographics of femoral hernias
More common in women, 40% present as emergencies
What level do gonads form at?
T10
Gubernaculum
Connects gonads to future scrotal swelling (or uterus in females)
Processus vaginalis
Evagination of peritoneal cavity
Spermatic cord contents
- Vas deferens
- Testicular A/V
- Pampiniform plexus
- Gonadal N’s
- LNs
Scrotum and testes lymph drainage
Scrotum -> superficial inguinal LNs
Testes -> lumbar and pre-aortic LNs
Cryptorchid testis
Undescended testis -> increased risk of testicular CA
Persistent processus vaginalis
Patent connection between tunica vaginalis and abdomen
Hydrocele
Peritoneal fluid accumulation within tunica vaginalis
How to detect a hydrocele
Transillumination: if light passes thru -> hydrocele instead of hematocele
Hematocele
Blood accumulation in tunica vaginalis
