anterior abdominal wall V2 Flashcards
what are the layers from superficial to deep in the anterior abdominal wall?
skin
2 layers of superficial fascia
muscles and fascia
transversalis fascia
extraperitoneal fat
parietal peritoneum
does the anterior abdominal wall has deep fascia ?
no deep fascia in the anterior abdominal wall ( like face, scalp )
instead of deep fascia it has 2 superficial fascia
what are 2 superficial fascia layers?
superficial fatty layer : campers
deep membranous layer : scarpa’s layer
what is the muscle found in the midline?
rectus abdominus
under which layer we will find the rectus abdominus ?
superficial fascia layer
what are the muscles found on the sides? ( anterolateral )
3 anterolateral muscles
External oblique
internal oblique
transversus abdominis
what layer will be below transversalis abdominis ?
transversalis fascia
what can we access after cutting the parietal peritoneum ?
the greater sac ( largest and most anterior sac )
what does the superficial fascia contain?
fat
Cutaneous vessels
nerves
the vessels and nerves run in the same direction of fibers –> usually horizontal
what are cleavage lines / langers line ?
variety of incision which when possible :
Avoid nerves ( especially motor
split the muscles in the direction of their fibers
what is watershed line ?
imaginary transumbilical line across the umbilicus
where do the lymph drain above watershed line?
similar to the veins UPWARDS and toward the axillary lymph nodes
where do the lymph drains below watershed line?
similar to the veins, drain DOWNWARD and toward the inguinal lymph nodes
whats the clinical significance of watershed line?
expect where a tumor will migrate if it was below or above the line
at which point is the superficial fascia divided into a single layer and at which point it is 2 layers?
a line joining the 2 anterior superior iliac spine
above it = single layer
below it : splits into 2 layers
what are the characteristics of superficial fascia? ( Campers fascia )
continuous with the superficial fascia of the thorax and thigh
excess fat accumulates in it
liposuction /removal of fat occur in this layer
where does the deep membranous layer pass through ( the scarpa’s fascia )?
inferiorly it passes over the inguinal ligament to fuse with the deep fascia of the thigh ( fascia lata )
what is holdens line?
a line from the deep membranous fascia passing over the inguinal ligament to fuse with the deep fascia of the thigh
attached not continuous
what is the colle’s fascia
deep membranous fascia continuing with the fascia of the perineum
what is the significance of the deep membranous fascia being attached and not continuous with the fascia of the thigh ( lata)?
it doesnt allow anything to go down in cases like the urethra rupturing ( urine wont be able to go the thigh and instead it will accumulate behind holdens line like a pocket )
what are the anterior abdominal wall muscles?
external oblique
internal oblique
transversus abdominis
rectus abdominis
pyramidalis
cremaster
what happens to the external oblique and internal oblique , transversus abdominis as they approach the mid clavicular line?
they become aponeurotic ( linea semilunaris )
what does the aponeuroses do?
surround and form a sheath around rectus abdominis muscle
what does pyramidalis and cremaster muscles surround?
testicles
what is the origin of external oblique ?
8 fleshy slips from the outer surface and lower border of 8 ribs ( 5-12 )
what is the insertion of external oblique?
anterior 1/2 of outer lip of iliac crest
posterior margin is free ( other 2 muscles are attached posteriorly to the thoracolumbar fascia )
anteriorly the aponeurosis decussates at linea alba and becomes continuous with the aponeurosis of the contralateral external oblique ( 2 aponeurosis join together )
what are the functions of the external oblique muscle?
insertion moves towards origin —> elevate the pelvis
what are the directions of the fibers of external oblique ?
downward and forward
what does the external oblique muscle continue as in the inguinal region?
inguinal ligament
what is the superficial inguinal ring ?
an opening in the aponeurosis of the external oblique muscle and it is surrounded by the fibers to keep the opening in control
what is the function of this structure?
allow structures like the spermatic cord in males and round ligament in females to pass through
what is linea alba?
midline fibrous structures formed by the aponeurosis of the muscles ( collagen fibers/ raphe )
decussates and interweave aponeuroses of the 3 flat abdominal muscles
what is the extension of linea alba?
xiphoid process ( Wide )
pubic symphysis ( narrow )
what defect does the linea alba has ?
at the umbilical region it has a opening called UMBILICAL RING
what is the significance of linea alba?
median incision through the linea alba is a common surgical approach because :
1- consists of only connective tissue
2- doesnt contain important nerves or blood vessels
what is the inguinal ligament ( pouparts ligament )?
thickened lower border of the external oblique aponeurosis
what is the extension of inguinal ligament?
between pubic tubercle and anterior superior iliac spine
describe the shape of the lateral part of inguinal ligament?
oblique
describe the shape of the medial of inguinal ligament?
horizontal
what makes the inguinal ligament slight convex downwards?
fascia lata
what is the lacuna ligament?
triangular shaped ligament that is formed by the medial fibers of the inguinal ligament
so it is part of the inguinal ligament
also it supports the vessels and psoas major
what does the posterior free edge of inguinal ligament do?
( Behind the inguinal ligament )
also knows the lower part of inguinal ligament
provide pathway for the psoas major and femoral vessels and nerves
what is the superficial inguinal ring?
an opening ( triangular ) in the external oblique aponeurosis
where is the apex of the superficial inguinal ring point?
laterally
where is the base of the superficial inguinal ring point?
at the pubic crest
what are the borders of the superficial inguinal ring?
lateral and medial crura of the aponeurosis of the external oblique
what are the other contributions from the external oblique muscle?
lacunar ligament
pectineal ligament
reflected part of the inguinal ligament
what is the attachment of lacunar ligament ?
attached to the pectineal line
aka gimbernats ligament
what is pectineal ligament?
extension of the lacunar ligament along the entire pectineal line of the pubic bone
aka ligament of cooper
what is the reflected part of the inguinal ligament ?
fibers start from the lateral crus and extend to the opposite side under the medial crus
what is the function of the reflected part of the inguinal ligament?
strengthens the inguinal canal
what is the origin of the internal oblique muscle ?
thoraco-lumbar fascia ( posterior attachment unlike the external oblique )
intermediate lip of iliac crest ( external was outer lip )
lateral 2/3 of inguinal ligament
how does the internal oblique muscles fibers run?
upward and medially
what is the insertion of internal oblique ?
inserted at the lower 3 or 4 ribs ( 9-12 )
costal cart
what is the function of the internal oblique?
moves the insertion towards the origin —-> the ribs and trunk downwards like crunches
why is it not easy to cut the external oblique aponeurosis ?
because the external oblique aponeurosis forms the inguinal ligament and the inguinal ligament gives origin for the internal oblique
what is the origin of transverse abdominis ?
Lower 6 ribs and costal cartilage ( 7-12 ) ( external = lower 8 , internal = lower 3-4 )
thoraco lumbar fascia
inner lip of iliac crest ( external = outer / internal = intermediate )
Lateral 1/3 of inguinal ligament ( internal was Lateral 2/3 of inguinal ligament )
what is the insertion of transverse abdominis?
inguinal fibers form the roof of the inguinal canal then becomes aponeurosis ——-> insert into pubic crest
medial part of pectin pubis / petineal line
in relation to the deep inguinal ring where does the transverse abdominis pass?
doesn’t pass in front of the deep inguinal ring ——> behind it
what muscles u will find if u cut laterally?
all 3 , external , internal , transverse
what muscles u will find if you cut medially?
only internal and external
not transverse because it is present laterally only
since we only have 2 muscles on the medial side instead of 3 = the medial side is weaker than the lateral and prone for hernia
are the anterior muscles abdominal muscles present everywhere anteriorly ?
No its only below the rib insertion
for external it is found at the lower 8 ribs ( 5-12 ) if you go to 4 u wont find it
for internal it is found at the lower 3-4 ribs ( 8-12 ) if you go to 7 u wont find it
for transverse abdominis it is found at the lower 6 ribs ( 7-12 ) if you go to 6 or 5th u wont find it
what is enclosed within the aponeurosis of the 3 muscles?
rectus abdominis
it is called rectus sheath
what is linea semilunaris ?
line where the anterolateral muscles end and become aponeurotic
what is the conjoint tendon / falx inguinalis?
at the superficial inguinal ring —-> the tendons of internal oblique and transverse abdominis fuse together forming the conjoint tendon
what is inguinal canal?
inter muscular canal between the deep and superficial ring of the inguinal ligament
what is the shape of the canal? and the reason behind it?
oblique canal
cuz when intraabdominal pressure increases during cough for example : the canal is compressed by surrounding muscles - having it oblique , prevents the abdominal content from herniating
what is the location deep inguinal ring?
superomedial to the inguinal ligament ——–>midinguinal point ( where the femoral artery is present )
what is the deep inguinal ring ?
opening in the transversalis fascia
what does the opening of the deep inguinal ring pierce?
pierces the internal oblique
but doesnt pierce the transversus abdominis as it is more lateral compared to internal oblique
what is the interfoveolar ligament ? ( hesselbachs)
thickening of the fascia transversalis in an area medial to the deep inguinal ring
and below it is known as iliopubic tract
what is the function of the interfoveolar ligament/ the thickening of transversalis ?
to reduce and minimize the risk of intestinal protrusion
the transversus abdominis is attached to which crus?
superior crus of the deep inguinal ring , so during the contraction , it pulls the ring laterally and increase the obliquity of the exit
what cord pass through the deep inguinal ring?
spermatic cord
what is the other name of iliopubic tract?
thomson ligament —> thickening of fascia transversalis
what forms the inferior boundary of the deep inguinal ring?
iliopubic tract / interfoveolar ligament
describe rectus abdominis?
vertically running muscle that is wider above than below
what is the origin of rectus abdominis ?
medial head : anterior surface of pubic symphysis
Lateral head : lateral part of pubic crest and pubic tubercle
what is the insertions of rectus abdominis?
fleshy medial xiphoid process
5-7 costal cartilage
which part of rectus sheath is formed by the external oblique aponeurosis ?
the anterior part layer of rectus sheath
it is has higher origin ( lower 8 ribs ) so it covers it from the beginning
which part of the rectus sheath is formed by the internal oblique aponeurosis ?
anterior and posterior parts
( only starts below the costal margin as it has lowers origin ) , lower 3-4 ribs
which part of the rectus sheath is formed by the transversus abdominis ?
posterior layer of rectus sheath
below arcuate line as it has low origin ( lower 6 costal cartilage
what is the extension of the internal oblique where it takes a part of rectus sheath?
it keeps splitting from the costal margin —–> until the midway between umbilicus and pubic symphysis
what happens below the midway between umbilicus and pubic symphysis ?
the internal oblique does not split but passes with the transversus in front of the muscle
what is arcuate line?
lower free edge of the posterior wall of the rectus sheath
where is the locations arcuate line?
located midway between the umbilicus and pubic symphysis
what forms the anterior and posterior wall of rectus sheath ABOVE the costal margin?
anterior wall : only external aponeurosis
posterior : N/A - the recuts muscle lies on the 5-7 costal cartilage
what forms the anterior and posterior wall of rectus sheath BETWEEN the costal margin and arcuate line?
anterior : external + anterior lamina of internal oblique aponeurosis
posterior : Internal oblique aponeurosis + transversus abdominis
what forms the anterior and posterior wall of rectus sheath BELOW the arcuate line?
anterior : all 3 muscles aponeurosis
posterior : transversalis fascia and peritoneum
what is the rectus abdominis attached to anteriorly?
the anterior rectus sheath
what is rectus abdominis attached to posteriorly?
it is not attached to the posterior rectus sheath layer forming a space
what are the locations of the tendinous intersection of rectus abdominis?
tip of xiphoid process
midway between xiphoid process and umbilicus
umbilicus
these divides the muscle into 4 parts
why cant we make transverse incisions through the tendinous intersections?
because the muscle runs longitudinally and transverse incisions would damage the muscle and the vessels
what is para median incisions?
anterior incisions near the median plane through the anterior layer of rectus sheath
then the muscle is retracted laterally
after that the posterior rectus sheath and the peritoneum are cut to access the peritoneal cavity
why is the rectus abdominis retracted laterally and not medially ?
because the superior and inferior epigastric vessels are near the midline
what is the content of rectus sheath?
rectus abdominis muscle
pyramidalis
superior and inferior epigastric vessels
7-11 intercostal and subcostal nerves
lymphatic vessels
what are the actions of rectus abdominis?
crunches – flexing the lumbar spine + pull your body up
when the pelvis is fixed the rib cage can be brought up to the pelvis
when the rib cage is fixed —-> leg and hip raise
upper limb is fixed —> lift legs to the point where toes reach the same lvl of upper limbs
describe the pyramidalis ?
small triangular muscle
lies anterior to the inferior part of rectus abdominis
extends from the pubis to linea alba
what is the function of pyramidalis ?
tenses the linea alba
what is the action of all the anterior abdominal wall?
increase intra-abdominal pressure
what is the action of the external and internal oblique muscles if both sides are used ?
flexion of trunk
what is the action of the external and internal oblique muscles in ONE sides only?
lateral flexion of the trunk
what is the function of oblique muscle?
rotation of trunk
what is the action of external oblique ?
lift up the pelvis
what is the action of internal oblique?
opposite to external instead of lifting up the pelvis it brings down the rib cuz the insertion is the rib
what is the location of the neurovascular plane?
lies in between the middle and deepest layers of muscle
between the internal oblique muscle and transversus abdominis
corresponds with the neurovascular plane in the intercostal spaces
what is the nerve supply of the anterolateral abdominal wall?
ventral rami of the lower 6 thoracic nerves
Ventral rami of L1
what nerve supply the skin near the umbilicus ?
T10
what is the significance of T10 supplying the skin near the umbilicus ?
because any visceras supplied by T10 will refer the pain to the umbilicus
like the appendix
what is the subcostal nerve?
T12 –> its called subcostal cuz its not in an intercostal space
what does the subcostal (T12 ) Supply?
skin above the inguinal ligament
inferior part of external oblique , internal oblique muscle and transversus abdominis, rectus abdominis , pyramidalis
what is iliohypogastric nerve?
branch from L1
what does iliohypogastric nerve supply?
supplies obliques muscles , transversus abdominis muscle
skin over the inguinal region
hypogastric region
what is ilioinguinal nerve?
branch from L1
what does ilioinguinal nerve supply?
supply oblique muscles, transversus abdominus
skin of scrotum , labia majora
upper medial thigh
what will happen if iliohypogastric nerve is damaged?
the lower area of the stomach will be weak ( hypogastric n inguinal )
what will happen if ilioinguinal is injured?
sensation of upper and medial aspect of the thigh and genitals is gone
what are the MAIN arteries that supply the anterolateral abdominal wall?
superior epigastric artery ( terminal branch of internal mammary artery )
inferior epigastric artery
what is the course of superior epigastric?
terminal branch of internal thoracic artery —> enter the rectus sheath , runs behind the rectus abdominis —> close to the posterior wall
what is the course of inferior epigastric artery?
branch of external iliac———> enter the rectus sheath through the arcuate line —-> goes posterior wall like the superior
where does the anastomose happen between superior and inferior epigastric artery ?
in the posterior wall behind rectus sheath
what are other arteries that supply the anterior abdominal wall?
10th and 11th posterior intercostal and subcostal arteries —> from aorta
Lumbar arteries —-> aorta
deep circumflex iliac —-> external iliac ( gives inferior epigastric as well )
Superficial circumflex iliac —> femoral artery
superficial epigastric —> femoral artery
where does the SUPERIOR superficial veins drain?
lateral thoracic and internal thoracic vein
lateral is tributary of axillary veins
where does the INFERIOR superficial veins drain?
superficial epigastric veins
its a tributary of femoral vein
where do the paraumbilical superficial veins drain?
portal vein through the round ligament of the liver
what happens to the paraumbilical vein in portal hypertension?
distention of paraumbilical veins –> caput medusae
what are thoracoepigastric vein ?
may exist or develop due to altered venous flow
veins between the superficial epigastric vein ( Drained into by inferior superficial vein ) and lateral thoracic vein ( Drained into by superior superficial vein
where do the deep veins drain?
corresponding to the arteries
what are the anastomosis that happen between the deep vein ?
anastomosis between inferior epigastric vein and superior epigastric vein
where does superior epigastric vein come from?
subclavian vein tributary
where does inferior epigastric vein come from?
external iliac vein tributary
what is the point of the anastomosis between the deep vein and superficial veins?
give collateral circulation during blockage of either vena cava
what do the lymphatic vessels accompany ?
the veins
Superficial lymph vessels accompany superficial veins
Deep lymph vessels accompany deep veins
what is the lymph drainage of the area superior to the umbilicus?
axillary lymph nodes
parasternal lymph nodes
because its above the watershed line
what is the lymph drainage below umbilicus ?
superficial inguinal lymph nodes
because its below the watershed line
where do the deep lymph vessels drain into?
external iliac lymph nodes
common iliac lymph nodes
lumbar lymph nodes
what are the features of the internal surface of abdominal wall?
median umbilical fold
medial umbilical fold
lateral umbilical fold
round ligament of the liver ( Which through the paraumbilical superficial veins drain into portal vein )
what is the extension of the median umbilical fold?
extends from the apex of urinary bladder
what does the median umbilical fold cover?
median umbilical ligament —> Which is a remnant of urachus
what does the medial umbilical fold cover?
cover the medial umbilical ligament —> obliterated
by umbilical arteries
what covers the lateral umbilical folds?
inferior epigastric vessels
what is the location of round ligament of liver?
lower free border of the falciform ligament
what is the round ligament of liver?
fibrous remnant of umbilical vein which extends from umbilicus to the liver
how is endoscopy is performed in the abdomen ?
tiny perforation are made in the abdominal wall allow the entry of remotely operating instruments
these procedure are replacing the conventional incisions
what are the benefits of these surgeries?
reduce the potential nerve injury , incisional hernia and contamination
and the time for healing is minimized
describe gridiron ( muscle splitting ) incision ?
used for appendectomy
made at mcburney point 2.5 cm superomedial to the anterior superior iliac spine on the spinoumbilical line
the skin incisions are oblique or transverse
muscle fibers need only be separated not cut giving sufficient access , the muscles are separated in the the direction of the fibers
When incision is closed the muscle fibers come together and the abdominal wall is as strong as it was before operation
which nerve is identified deep to the internal oblique ?
iliohypogastric nerve
it is identified and preserved cuz damage to the nerve weakens the muscle and increases the possibility of subsequent inguinal hernia
what is incisional hernia ?
protrusion of omentum or organ through surgical incision
due to improper incisions , infections , old age, debility, obesity
