Anatomy of Anterior Abdomen Wall Flashcards
what are the 3 lateral layers of abdominal wall muscles?
- external oblique:
- internal oblique
- transversus abdominis
what are the 3 lateral layers of abdominal wall muscles? & rectus abdominus
which direction do they run?
what do they attach to superioly and inferiorly?
1. external oblique:
- fibres run anterior-inferior direction
- insert superiorly on lower ribs and inferiorly on iliac crest
- run to mid-clavicular line - where get aponeurosis: essentially the same as a normal tendon but instead is a thin, flat sheet. Muscle is attached to bone by tendon, yet because abdominal muscles are like a sheath they have a very thin and flat tendon known as an aponeurosis.
2. internal oblique
- run anterior-superior direction
- insert superiorly on lower ribs and inferiorly on iliac crest
- ends on mid-clavicular line and becomes aponeurotic.
3. transversus abdominis
- deep layer that runs transverse across
- aponeurotic at the mid-clavicular line.
4. rectus abdominis
- 6 pack muscle
- runs from xiphoid proceess to pubic symphysis
- have tenionus intersections (which make 6 pack shape)
blue and purple muscles?
blue: pectoralis major
purple: serratus minor
which is this muscle?
external oblique
describe the structure of the rectus sheath
a) above arcuate line
b) below arcuate line
rectus sheath:
- surrounds rectus abdominis muscle
- made from: aponeuroses of external oblique, internal oblique and transverse abdominis
-
structure:
a) above arcuate line
i) external oblique aponeuroses runs anterior to rectus abdmonis & inserts into the midline: forms linea alba
ii) internal oblique aponeuroses splits in half: half goes anterior of rectus abdominis, other half goes posterior. again insets onto linea alba
iii) transversus abdominis runs posterior to rectus abdominis
iv) transversalid fascia runs posterior to rectus abdominis
b) below arcuate line:
i) all of aponeuroses run anterior to rectus abdominis
ii) transveralis fascia runs posterior to rectus abdominis
what muscle is this?
transversus abdominis
what is the blood supply to the abdominal wall like? (3) where from?
internal thoracic artery –> superior epigastric artery
external iliac artery –> inferior epigastric artery
lower intercost and lumbar arteries - blood to lateral aspect of ab wall.
where do you find the inguinal ligament?
attachment site of the external oblique? (3)
what is the inguinal ligament? - between which two points does it lie? (2)
what lies underneath the inguinal ligament? (2)
attachment site of external oblique
- *- lower part of ribs
- the anterior superior iliac spine (ASIS for short)
- external pubic tubercle.**
The muscle will not attach in-between these two points.
inguinal ligament:
- the inferior border of the external oblique’s aponeurosis (between ASIS & pubic tubercle) and it rolls under itself to create the inguinal ligament.
- under inguinal ligament:
a) passageway for the femoral artery, vein and nerve pass & enter thigh.
b) spermatic cord:
label xox
describe the path of inguinal canal & how made
inguinal canal:
- passageway through ab. wall and runs along inferior aspect of inguinal ligament
- created during descent of testes until reach the scrotum.
describe the pathway of femoral artery and vein & spermatic cord, as seen in this diagram
- femoral artery and vein are below inguinal ligament
- spermatic cord goes through the abdominal wall and inguinal canal (which is inside inguinal ligament) and towards scrotum
what is a hernia?
what is an inguinal hernia and femoral hernia?
hernia: protrusion of abdominal contents through a weakness in abdominal wall (e.g peritoneum or viscera)
inguinal hernia:
- 75% of hernias.
- contents of the abdomen protrude through the inguinal canal. They can be varyingly serious.
femoral hernias:
- abdominal contents protude in area that goes underneath the inguinal ligament, where femoral vasculature is
how is the abdomen divided up in 9 regions?
how do we divide the gut ? (3) - which bits of gut make each part?
which arteries supply each? ^
- *foregut:** oesphagus, stomach, 1st part duodenum, liver, pancreas, spleen
- blood supply: coleac trunk
- *midgut:** 2/3rds of duodenum, jejunum and ileum, colon - up to 2/3rds of transverse colon
- blood supply: superior mesenteric artery
- *hindgut:** last 1/3rd of transverse colon, descending colon, rectum and upper canal.
- blood supply: inferior mesenteric artery