90 - Anterior Abdominal Wall Flashcards
Layers encountered if cutting into anterior abdominal wall 1 2 3 4 5 6 7
1) Skin 2) Superficial fascia (fatty layer) 3) Superficial fascia (membranous layer) 4) External oblique muscle 5) Internal oblique muscle 6) Transversus abdominus 7) Extraperitoneal fascia
Tissue layout of obliques and transversalis abdominis
Fleshy laterally, aponeurotic medially
Muscle with a free inferior edge
External oblique
Inguinal ligament
Free inferior edge of the external oblique. Is thickened, curls inwards.
Attachments of inguinal ligament
Lateral border attaches to iliac crest. Attachment at anterior superior iliac spine, public tubercule, with a free edge between.
Attachments of the internal oblique
1) Attaches to costal margin superiorly 2) Attaches to lateral 2/3 inguinal ligament, anterior iliac crest laterally. 3) Upper fibres join at linea alba. 4) Lower fibres arch upwards, over, downwards, join public crest.
Attachments of the internal oblique 1 2 3 4
1) Attaches to costal margin superiorly 2) Attaches to lateral 2/3 inguinal ligament, anterior iliac crest laterally. 3) Upper fibres join at linea alba. 4) Lower fibres arch upwards, over, downwards, join public crest.
Where on the posterior abdominal wall do the obliques and transversalis abdominis join?
Thoracolumbar fascia
Where do the lowermost fibres of the internal obliques arise from?
Lateral 1/3 of inguinal ligament
Muscles sharing a conjoined tendon inserting into the pubic crest
Internal and external oblique
*Configuration of rectus abdominis sheath above umbilicus
*Configuration of rectus abdominis sheath below umbilicus
Where does rectus abdominis arise from?
Pubic crest
What does rectus abdominis attach to?
Costal cartilages 5, 6, 7
What creates the ‘six pack’ shape?
Tendinous disruptions to vertical ascent of muscle fibres (3x).
What forms the rectus abdominis sheath?
Aponeuroses from three muscles (internal, external obliques, transversus abdominis)
Muscle whose aponeurosis encloses rectus abdominis from both anterior and posterior
Internal oblique
Level at which all aponeuroses of internal, external obliques and transversus abdominis travel superficial to rectus abdominis?
Inferior to umbilicus
Name for where the posterior rectus abdominis sheath ends
Arcurate line
Where does the abdominal neurovascular plane lie?
Between the internal obliques and transverse abdominis
Main arterial supplies of anterior abdominal wall 1 2
1) Superior epigastric artery (branches from internal thoracic) 2) Inferior epigastric artery (branches from external iliac artery)
Venous drainage of anterior abdominal wall
Dual drainage. Portal and systemic drainage.
Between which two points does the inguinal ligament stretch?
BEtween iliac spine and public tubercle
What marks the pelvic inlet?
Pectineal line of pelvic bone
What is the lacunar ligament?
Extension of inguinal ligament to the pectineal line
Layers through which developing testes needed to descend. 1 2 3 4 5
1) Peritoneum 2) Extraperitoneal fat 3) Transversalis fascia 4) Transversus abdominis 5) Internal, external obliques
How do the testes get past the transversalis fascia in development?
Deficiency in fascia transversalis through which testes descned is halfway between anterior superior iliac spine (ASIS) and public tubercle. A finger’s breadth above the inguinal ligament.
ASIS
Anterior superior iliac spine
Where do the testes descend, relative to the inguinal ligament?
Descend underneath inguinal ligament
How do the testes get past the internal obliques in development?
Internal oblique, transversus abdominis form a tunnel at the inguinal ligament. They then arch upwards, around, downwards to join the pubic tubercle.
How do the testes get past the internal obliques in development?
Internal oblique, transversus abdominis form a tunnel at the inguinal ligament. They then arch upwards, around, downwards to join the pubic tubercle. Testes don’t have to penetrate. Travel through the tunnel, go through triangular deficiency between public tubercle and public crest
What forms the fascia surrounding the testes?
Each layer the testes pass through in development gives the testes another layer of fascia
Layers of fascia around testes 1 2 3
1) Internal spermatic fascia 2) Cremasteric fascia 3) External spermatic fascia
Where does the internal spermatic fascia come from?
Fascia transversalis
Where does the cremastic fascia come from?
From transversus abdominis and internal oblique
Fascia responsible for the contraction of the scrotum
Cremastic fascia
Where does the external spermatic fascia come from?
External oblique
Abdominal hernia
Unusual protrusion of abdominal contents through the abdominal wall
Inguinal hernia
Herniation through the inguinal canal
*How do the femoral artery and vein pass from the abdomen to the lower limb?
Superficial ring
Medial opening in external oblique aponeurosis (in the inguinal canal)
Deep ring
Deficiency (“outpouching”) in fascia transversalis (in the inguinal canal)
Inguinal canal
Slit-like passage extending downwards and medially above and parallel to medial half of inguinal ligament
Floor of inguinal canal
Inguinal ligament
Roof of inguinal canal
Arching fibres of internal oblique and transversus abdominus
Anterior wall of inguinal canal
External oblique aponeurosis, internal oblique muscle(lat)
Posterior wall of inguinal canal
Transversalis fascia, Conjoined tendon (medially)
Indirect inguinal hernia
A protrusion through the deep ring into the inguinal canal
Superficial ring
Medial opening in external oblique aponeurosis (into the inguinal canal)
Deep ring
Deficiency (“outpouching”) in fascia transversalis (into the inguinal canal)
Indirect inguinal hernia
A protrusion through the deep ring into the inguinal canal
Indirect herniae
Herniae that arise from incomplete closure of the processus vaginalis, hence the herniated peritoneal contents extend into the scrotum (or labia)
Direct herniae
A protrusion forwards into the inguinal canal through an area of weakness in its posterior wall
