Chapter 1 - Anterior Abdominal Wall(from pyramidalis) Flashcards
Deep N of AAW
lower 6 thoracic N, iliohypogastric and ilioinguinal N
they finally emerge as cutaneous N
Deep arteries of AAW
2 from above - superior epigastric, musculophrenic
2 from below - inferior epigastric, deep circumflex iliac
Branches of intercostal, subcostal and lumbar
Superior epigastric A
- from internal thoracic A
- begins in 6th intercostal space
- enters rectus sheath
- runs vertically down
- supplies rectus
- ends by anastamosing with inferior epigastric A
- gives muscular, cutaneous banches
- gives hepatic branch for falciform ligament
- gives anastamotic branch at level of xiphoid process
Musculophrenic A
- from internal thoracic A
- runs downwards and laterally
- pierces diaphragm b/w 7th-8th cartilages
- gives branches to diaphragm, AAW and 7, 8, 9 intercostal spaces
Inferior epigastric A
- from external iliac A
- arises from just above inguinal ligament
- passes medial to deep inguinal ring
- pierces fascia transversalis
- enters rectus sheath
- supplies rectus muscle
- anastamoses with sup. epigastric A
- gives:
cremasteric branch
pubic branch
muscular branch
cutaneous branch
Deep circumflex iliac A
- from external iliac A
- runs behind inguinal ligament
- continues along iliac crest
- pierces transversus abdominis
- anastamoses with superior gluteal, lateral circumflex femoral and superficial circumflex iliac A
Definition of rectus sheath
Aponeurotic sheath covering rectus abdominis
Features of rectus sheath
ANTERIOR WALL
- complete
- adherent to tendinous intersections of muscle
POSTERIOR WALL
- incomplete
- deficient above costal margin and below arcuate line
- free from muscle
Both walls extend till linea semilunaris
Formation of rectus sheath
ABOVE COSTAL MARGIN
AW: ext. oblique aponeurosis
PW: deficient
B/W COSTAL MARGIN, ARCUATE LINE
AW: ext. oblique aponeurosis + anterior lamina of int. oblique aponeurosis
PW: posterior lamina of int. oblique aponeurosis + aponeurosis of transversus
BELOW ARCUATE LINE
AW: Aponeurosis of all 3 flat muscles
PW: deficient
Contents of rectus sheath
- Rectus abdominis
- Pyramidalis
- Sup. epigastric A
- Inf. epigastric A
- Sup., Inf. epigastric venae comittantes
- Terminal parts of lower 6 thoracic N
Functions of rectus sheath
- Checks bowing of rectus muscle
- Increases efficiency of muscle
- Maintains strength of AAW
Define fascia transversalis
Part of fascia that lines inner surface of transversus abdominis
Extent of fascia transversalis
A: adheres to linea alba
P: merges with anterior layer of thoracolumbar fascia. continues with renal fascia
Sup: continuous with diaphragmatic fascia
Inf: attached to inner lip of iliac crest and inguinal ligament
Med: attached to pubic tubercle
Deep inguinal ring
- oval opening in fascia transversalis 1.2cm above midinguinal point
- lies lateral to inferior epigastric A
- transmits spermatic cord/round ligament of uterus
Prolongations of fascia transversalis
- Tubular prolongation surrounds spermatic cord - internal spermatic fascia
- Forms anterior wall of femoral sheath
Definition of spermatic cord
- oblique intermuscular passage in lower part of abdominal wall
- directed downwards, forwards, medially
- extends from deep inguinal ring to superficial inguinal ring
Anterior boundaries of inguinal canal
Whole extent: 1. Skin 2. Superficial fascia 3. Ext. oblique aponeurosis Lat 1/3: 1. Int. oblique muscle
Posterior boundaries of inguinal canal
Whole extent: 1. Fascia transversalis 2. Extraperitoneal tissue 3. Parietal peritoneum Medial 2/3 1. Conjoint tendon 2. Reflected part of inguinal ligament
Roof and floor of inguinal canal
Roof: int. oblique, transversus abdominis
Floor: inguinal, lacunar ligament
Structures passing through inguinal canal
- Spermatic cord/round ligament of uterus. It enters through deep IR and goes out through SIR
- Ilioinguinal N. It enters b/w ext. and int. oblique and passes out through SIR.
Constituents of spermatic cord
- Testicular A
- Cremasteric A
- A to ductus deferens
- Genital branch of genitofemoral N
- Ilioinguinal N
- Autonomic N
- Ductus deferens
- Pampiniform plexus
- Remains of processus vaginalis
Coverings of spermatic cord
- Internal spermatic fascia from fascia transversalis
- Cremasteric fascia from muscle loops of cremaster M. Derived from int. oblique and transversus abdominis
- External spermatic fascia from ext. oblique
Describe hernia
- protrusion of abdominal contents through any of its walls or into ‘no entry’ zone within abdominal cavity
- consists of sac, contents, and coverings.
- sac consists of neck and body.
Complications of hernia
- Irreducibility - loop goes out but does not return
- Obstruction - loop may get narrowed in parts and contents cannot move forward.
- Strangulation - arterial supply is blocked and loop gets necrosed
Internal hernia
- protrusion of loop of intestine within ‘no entry’ zone of abdominal cavity
- usually in epiploic foramen/lesser sac/foramen of Winslow
- mostly gets strangulated
Congenital umbilical hernia
due to non-return of midgut loop into abdominal cavity
Acquired infantile umbilical hernia
due to weakness of umbilical scar, a part of gut protrudes out.
disappears as infant grows
Paraumbilical hernia
loop of intestine protrudes through linea alba around umbilicus
Femoral hernia
- seen more in females due to large pelvis, smaller blood vessels and larger femoral canal
- neck lies below and lateral to pubic tubercle
Inguinal hernia
- protrusion of loop of intestine through inguinal canal
Indirect/Oblique - protrudes through DIR, inguinal canal, SIR, into scrotum.
Direct - protrudes through posterior abdominal wall/ Hesselbachs triangle
Coverings of indirect inguinal hernia
- Extraperitoneal tissue
- Internal spermatic fascia
- Cremasteric fascia
- External spermatic fascia
- Skin
Boundaries of Hesselbach’s triangle
Inferior epigastric A
Lateral border of rectus abdominis
Inguinal ligament
Coverings of lateral direct inguinal hernia
- Extraperitoneal tissue
- Fascia transversalis
- Cremasteric fascia
- External spermatic fascia
- Skin
Coverings of medial direct inguinal hernia
- Extraperitoneal tissue
- Fascia transversalis
- Conjoint tendon
- External spermatic fascia
- Skin
Epigastric hernia
occurs through upper part of linea alba
Divarication of recti
- occurs in multiparous females with weak anterolateral abdominal muscles
- loops of intestine protrude during coughing but return back
Lumbar hernia
protrudes through lumbar triangle in posterior abdominal wall
Boundaries of lumbar triangle
Iliac creat
Anterior border of latissimus dorsi
Posterior border of ext. oblique
