Anterolateral Abdominal Wall Flashcards
what are the 4 quadrants of the abdomen
right upper
left upper
right lower
left lower
what are the 2 planes that divide the abdomen
median plane
trans-umbilical plane
what level is the transumbilical plane
IV disc between L3 and L4
the abdominal wall can also be divided into __ regions
9
what lines divide the abdomen into regions
mid-clavicular
subcostal
trans-tubercular
what are the 9 regions of the abdomen
- right and left hypochondria
- epigastric
- right and left lumbar
- umbilical
- right and left inguinal
- suprapubic
name the layers of the abdomen from external to internal
- skin
- superficial fascia
- muscles of the anterolateral body wall and their assoc. fascial structures
- extraperitoneal fascia
- parietal peritoneum
where is the extraperitoneal fascia most evident and why
posterior wall
contains retroperitoneal structures e.g. kidneys
what is the superficial fascia
fatty layer that contains small cutaneous nerves and vessels
the deepest layer of abdominal wall is the
parietal peritoneum
describe the difference in the superficial fascia above and below the umbilicus
above umbilicus superficial fascia is similar to that found elsewhere in the body
below the umbilicus superficial fascia divides into 2 layers
what 2 layers does the superficial fascia below the umbilicus divide into
Superficial (fatty) = Camper’s fascia
Deep (membranous) = Scarpa’s fascia
Camper’s fascia is a continuation of the fatty layer of superficial fascia across the abdominal wall and passes from the abdominal wall to blend with…
the superficial fascia of the thigh and perineum
continuous over inguinal ligament
how does camper’s fascia behave in the male pelvis
continues onto fascia of penis - loses fatty layer and fuses with deeper layer of superficial fascia to become dartos fascia of the scrotum
how does camper’s fascia behave in the female pelvis
retains fatty layer and contributes to fascia of the labia majora
compare Camper’s and scarpa’s fascia
Camper’s - fatty layer of varying thickness
Scarpa’s - thin, membranous with little fat
scarpa’s fascia is ____ to campers fascia
inferior/deep
where does Scarpa’s fasica attach in the midline
pubic symphysis and linea alba
below the inguinal ligament, Scarpa’s fasica fuses with… to form…
fascia of thigh to form fascia lata
how does Scarpa’s fasica become colles fascia
attaches to posterior part of perineal membrane (superficial perineal membrane - colles)
Scarpa’s fasica contributes what to males
fascia of penis
dartos fascia of scrotum
fundiform ligament of penis
Scarpa’s fasica contributes what to females
labia majora
what is the advantage of the muscle layers of the abdominal wall having fibres that run in different directions
forces run in different directions across the different layers which helps to spread stresses out across the wall during movement and allows the wall to be strong and flexible
why can you get a sore abdominal wall when you have a cold
abdominal wall supports the viscera when abdominal pressure increases - when you breathe the diaphragm descends pushing the abdominal viscera down - particularly noticable when you cough or sneeze and the abdominal wall contracts in response to sudden strong respiratory movements
as abdominal pressure increases what groups of muscles contract
abdominal wall muscles
pelvic diaphragm
as you dissect the abdominal wall what is the first muscle you will uncover
external oblique
muscle fibres of the external oblique go from where to where
fibres run infero-medial from ribs 5-12 to iliac crest and linea alba
what is the linea alba
formed from the aponeurosis of the left and right external oblique
what is the function of external obliques
flex trunk using both
turn to same side using one
why is rectus abdominus hidden from view
aponeurosis forms the anterior wall of the rectus sheath which hides rectus abdominus from view
as it reaches the pelvic bones, the aponeurosis forms what
fold over as it reaches the pelvic bones to form the anterior wall and floor of the inguinal canal - as it forms the floor of the inguinal canal it thickens and is described as the inguinal ligament
where does the inguinal ligament pass
between the ASIS and the pubic tubercle (one on each side)
where does the linea alba run
from xiphoid to pubic symphysis
the lower border of the linea alba forms what
inguinal ligament
nerve supply of external oblique
Anterior Rami T7-T12
the anterior rami that supply the external obliques are from
intercostal nerves of the thorax
nerve supply of external oblique is often referred to as
supply from the lower 6 intercostal nerves
T12 is also referred to as
subcostal nerve
compare internal and external oblique
internal - deep, smaller and thinner
internal oblique muscle fibres go from where to where
fibres run supero-medial from thoracolumbar fascia, inguinal ligament and iliac crest to ribs 10-12
where does the aponeurosis of internal oblique meet
meets in the midline at the linea alba
aponeurosis of internal oblique contributes to …
rectus sheath
nerve supply of internal oblique
anterior rami T7-T12 and L1
where is transversus abdominis found
deep to internal oblique
where do fibres of transversus abdominis run
transverse across abdominal wall
what is the function of transversus abdominis
support body wall