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
innervation of transversus abdominis
anterior rami of T7 to L1
where does transversus abdominis go between
thoracolumbar fascia
iliac crest
inguinal ligament
costal cartilages of ribs 7-12
linea alba
pubic crest
pectineal line
does transversus abdominis form an aponeurosis
yes and contributes to posterior wall of rectus sheath
what is the direction of fibres of the rectus abdominis
superior from pubic tubercle, crest and symphysis to xiphoid process and costal cartilages of ribs 5-7
what is the function of rectus abdominis
flexes trunk - sit ups
support/compression of abdominal wall
does rectus abdominis form an aponeurosis
no - contained within the rectus sheath
innervation of rectus abdominis
anterior rami of T7 - T12
what is the pyramidalis
small triangular muscle that may be found attaching to the linea alba - many individuals do not have it
what does the pyramidalis do
tense the linea alba
the pyramidalis is found ____ to the rectus abdominis
anterior
the pyramidalis runs from
pubis to linea alba
what is the nerve supply of the pyramidalis
anterior ramus T12
at the level of attachment of the rectus abdominis to the rib cage, where does the rectus abdominis lie (above the costal margin)
directly on the surface of the costal cartilages
the aponeurosis of what muscle forms the anterior wall of the rectus sheath
external oblique
above the umbilicus, the anterior wall of the sheath is composed of what
aponeuroses of external and internal oblique
above the umbilicus, the posterior wall of the rectus sheath is composed of what
aponeuroses of internal oblique and transversus abdominis
how does internal oblique contribute to both walls of the rectus sheath above the umbilicus
its aponeurosis forms 2 layers which pass around rectus abdominis
Below the umbilicus (half way between the umbilicus and pubic bones) where do the aponeuroses of the abdominal wall muscles lie
all anterior to rectus abdominis
Below the umbilicus (half way between the umbilicus and pubic bones), what forms the posterior wall of the rectus sheath
transversalis fascia
what is the arcuate line
transition point from a strong aponeurosis to the delicate transversalis fascia
Below the umbilicus (half way between the umbilicus and pubic bones) what does the rectus abdominis lie on
directly on transversalis fasica
structures in the extraperitoneal fascia are described as
retroperitoneal structures as they lie posterior to the peritoneum
what is the thin membranous layer that lines the inner walls of the abdominal cavity
parietal peritoneum
what is the thin membranous layer that covers the organs
visceral peritoneum
what is the function of the peritoneum
smooth lining for movement of the abdominal organs against the abdominal wall
how does the extraperitoneal fascia protect the kidneys
thicker on posterior wall and forms a large renal fat pad
what is found deep to transversalis fascia
layer of extraperitoneal fascia
what is the final wall layer
parietal peritoneum
what is found on the posterior surface of the anterior abdominal wall
3 folds
what are the 3 folds on the posterior surface of the anterior abdominal wall
median umbilical ligament
medial umbilical ligament
lateral umbilical fold
the median umbilical ligament is a remnant of what embryological structure
urachus remnant
the medial umbilical ligament is a remnant of what embryological structure
umbilical artery
how many median umbilical ligaments are there
1
how many medial umbilical ligaments are there
2 - one each side
how many lateral folds are there
2 - one each side
what is contained in the lateral folds
inferior epigastric artery and vein
where do the inferior epigastric artery and vein lie
directly inferior to rectus abdominis
the inferior epigastric artery and vein supply blood to/drain what
the anterior abdominal wall
where do the superficial nerves and vessels of the anterior abdominal wall run
in the superficial fascia
what do the superficial nerves and vessels of the anterior abdominal wall supply
the superficial fascia and skin
the superficial veins drain towards where
axilla or femoral vein
the superficial arteries arise from the
femoral artery (superficial circumflex iliac and superficial epigastric)
internal thoracic (musculophrenic and superior epigastric)
the superficial nerves are branches of
anterior and lateral branches of the intercostal nerves
what nerves supply the anterior abdominal wall
lateral cutaneous branches of 6-12 intercostal nerves and iliohypogastric nerve (L1)
anterior cutaneous branches of 6-12 intercostal nerves
what nerve supplies the wall in the inguinal region
iliohypogastric (L1)
what are the superficial arteries of the anterior abdominal wall
musculophrenic branch of internal thoracic; superficial epigastric and superficial circumflex iliac branches of femoral artery
name 2 superficial veins of the anterior abdominal wall
superficial epigastric veins
thoracoepigastric veins
the deeper vessels supply what
muscles of the abdominal walls
what supplies the upper part of the rectus abdominis
the superior epigastric artery
the superior epigastric artery is a terminal branch of what artery
internal thoracic artery
what artery supplies the rest of the rectus abdominis (not the upper part)
inferior epigastric artery
the inferior epigastric artery is a branch of what vessel
external iliac artery
from what nerve roots do the ilioinguinal and iliohypogastric nerves come from
L1
the ilioinguinal and iliohypogastric nerves supply sensory innervation to where
pubic region and medial thigh
the ilioinguinal and iliohypogastric nerves supply motor innervation to where
internal oblique and transversus abdominis
superficial lymphatic drainage above the umbilicus goes where
nodes in axilla
superficial lymphatic drainage below the umbilicus goes where
superficial inguinal nodes
deep lymphatic drainage of the upper region goes where
parasternal nodes
deep lymphatic drainage of the middle areas is to where
lumbar nodes
deep lymphatic drainage of the lower areas is to where
external iliac nodes
deep lymph nodes lie near…
arteries
parasternal nodes lie near what artery
internal thoracic artery
lumbar nodes lie either side of what artery
abdominal aorta
external iliac nodes surround what artery
external iliac artery
dermatome of umbilicus
T10
what are the main nerves supplying the anterolateral abdominal wall
intercostal nerves, with some supply from L1
what supplies the skin, muscle and parietal peritoneum of the anterolateral abdominal wall
anterior rami from T7-T11 (intercostal), T12 (subcostal) and L1 (iliohypogastric and ilioinguinal)
what branches supply the skin
lateral and anterior cutaneous branches
where do the intercostal nerves lie
between internal oblique and transversus abdominis, enter rectus sheath
