Abdominal wall Flashcards
What are the boundaries of the abdomen?
between thorax and pelvis
superior: diaphragm
posterior: lumbar vertebrae and muscles
lateral and anterior: abdominal muscles
inferior: pelvic inlet - from sacral promontory to pubic symphysis along pectineal line
What internal structure correlates with T8?
inferior vena cava opening
What internal structure correlates with T10?
esophageal hiatus
What internal structure correlates with T12?
aortic hiatus - abdominal aorta and celiac trunk
What internal structure correlates with L1?
transphyloric plane: 1st part of duodenum, 8th intercostal space, superior mesenteric artery
What internal structure correlates with L2?
renal artery (sometimes found at L1) and L diaphragm crus attachment
What internal structure correlates with L3?
subcostal plane: 12th rib, inferior mesenteric arteries
What internal structure correlates with L4?
supracristal plane, umbilicus, abdominal aorta divides into R/L common iliac arteries
What internal structure correlates with L5?
intertubercular plane, IVC formed by R/L common iliac veins
which two planes make up the borders of the quadrants?
median sagittal plane: xiphoid process and pubic symphysis
(vertical)
transumbilical plane
(horizontal across belly button)
which structures are found in the right upper quadrant?
liver
duodenum
which structure is found in the left upper quadrant?
stomach
which structures are found in the right lower quadrant?
cecum
ascending colon
appendix
which structures are found in the left lower quadrant?
descending colon
sigmoid colon
what is McBurney’s point?
appendix referral pain
aka appendicitis
which planes make up the 9 abdominal regions?
mid-clavicular plane (x2): mid clavicle and mid inguinal ligament
(two vertical planes)
subcostal (L3) or transpyloric (L1) plane
(top horizontal plane)
intertubercular plane (L5) (lower horizontal plane)
what are the 9 abdominal regions?
right hypochondrium epigastric left hypochondrium right lumbar/flank umbilical left lumbar/flank right inguinal/groin pubic left inguinal/groin
what are the posterior, lateral, and anterior innervations of the abdominal wall?
posterior: dorsal rami of spinal nerves
lateral: intercostal nerve & lateral cutaneous branch
anterior: intercostal nerve & anterior cutaneous branch
which muscle causes T6/T7 lateral cutaneous branch impingement and what happens because of it?
serratus anterior
causes shoulder problems
which landmark is at T6 dermatome?
xiphoid process
which landmark is at T10 dermatome?
umbilicus
which landmark is at T12 dermatome?
ASIS
What is the relationship between innervation and the spinal nerve in the abdomen dermatome?
the innervation does not correlate with the spinal nerve exiting level from spinal cord in the lower part due to the spinal cord stopping at T12-L2.
Example: T9 spinal nerve is innervated at the L3 vertebral level
What is the lateral blood supply for the anterolateral abdominal wall?
posterior intercostal vessels
what is the anterior blood supply for the anterolateral abdominal wall?
superior and inferior epigastric vessels
deep and superficial circumflex iliac artery
when there is an abdominal aorta malfunction, where do the lower extremities get blood supply from?
superior epigastric artery
when there is an inferior vena cava malfunction, where do lower extremities get their blood supply from?
blood can drain back to the superior vena cava
what is caput medusae?
portal hypertension
a cluster of swollen veins in your abdomen that stem from around the belly button.
this indicates a circulatory problem usually associated with liver disease
what are the 9 layers of the anterolateral abdominal wall? superficial to deep
skin superficial fascia: - fatty layer (Camper's) - membranous layer (scarpa's) external oblique muscle internal oblique muscle transversus abdominis muscle transversalis fascia extraperitoneal fascia parietal peritoneum
what is the clinical importance of the layers of the abdominal wall?
testis descending and herniation will push through different layers of structures
what direction do the external oblique muscles run?
superolateral to medio-inferior
“hands in pockets”
what direction does the internal oblique muscles run?
opposite of external oblique muscle
what are the two branches of L1 nerve and their parts?
iliohypogastric: internal oblique
ilioinguinal: cremaster part
what kind of muscle is the transversus abdominis?
a core muscle
between which muscle layers do the intercostal nerves run?
between transversus abdominis and internal oblique
what distal attachment narrows down and forms a weak point on the anterior abdominal wall?
pyramidalis
what is the function of the rectus sheath?
it protects and keeps together the rectus abdominis and pyramidalis.
the rectus abdominis is wrapped by aponeurosis of the 3 abdominal muscles
where is the arcuate line located?
~1/3 distance of umbilicus to pubic symphysis of posterior rectus abdominis
what structures are above the arcuate line?
superficial to rectus: aponeurosis of external oblique
half aponeurosis of internal oblique
deep to rectus: half aponeurosis of internal oblique
aponeurosis of transversus abdominis
what are the structures below the arcuate line?
superficial to rectus: all aponeurosis of 3 layers of muscles
deep to rectus: none - weakness of abdominal wall
what is aponeurosis fiber crossing and what is its function?
weaving of superficial and deep layers of same aponeurosis
function: improves strength and functions
what happens between two of the same layer obliques crossing?
intramuscular exchange, from superficial to deep
what happens between opposite external and internal oblique fiber crossing?
intermuscular exchange, from superficial to deep
the two different layers intertwine
what is the linea alba in relation to fiber crossing?
the midline of the aponeurosis fiber exchange
what are the umbilical folds/ligaments in order of lateral to medial?
lateral: inferior epigastric vessels
medial: remnant umbilical artery
median: remnant allantois (urachus), from umbilicus to suspend urinary bladder
what are the borders of Hesselbach’s triangle (inguinal triangle)?
lateral: medial of lateral umbilical fold
inferior: inguinal ligament
medial: lateral rectus abdominis
what is the placenta?
landmark of development completed in the 3rd week of gestation
- nutrients and oxygen exchange with mother’s blood occurs here
Do the placenta and embryo have direct contact?
No!
embryo does not have direct contact with the placenta of the mother
does the fetus always have the same blood type as mother?
No!
because there is no direct contact, the fetus can have a different blood type
how is the fetus and placenta connected if there is no direct contact?
through the umbilical cord
- blood vessels/urachus
- remnant structures after birth
what do the umbilical arteries turn into after birth?
2 medial umbilical ligaments/folds –> not fully remnant (with 2 branches)
where do the umbilical arteries run to?
2 internal iliac arteries to placenta
what does the umbilical vein turn into after birth?
ligament teres and ligamentum venosum
where does the umbilical vein run to?
to liver and continue to inferior vena cava (ductus venosus)
what does the allantois turn into after birth?
median umbilical ligament/fold
what is the function of the allantois?
fetal urine drainage
what does the foramen ovale turn into after birth?
fossa ovalis
where is the foramen ovale located?
opening between right and left atrium
what does the ductus arteriosus turn into after birth?
ligamentum arteriosum
what does the ductus arteriosus bridge?
bridging blood vessel between aorta and pulmonary trunk
what is internal hemorrhoids?
anastomosis with rectal vein to IVC
painless
what is esophageal varices?
anastomosis of portal vein branches to esophageal veins to SVC
what is caput medusae?
anastomosis with epigastric veins to IVC or SVC if IVC has problems
what happens after birth in caput medusae?
paraumbilical veins are close after birth.
this re-opens in portal hypertension
what is the inguinal ligament formed by?
external oblique aponeurosis
ASIS
pubic tubercle
what are the layers of inguinal canal?
external oblique aponeurosis as scaffold
internal oblique muscle slip
transversus abdominis
what part of the inguinal canal is the external oblique aponeurosis?
distal part forming superficial inguinal ring
what does the internal oblique muscle slip do?
cover inner structures
cremaster muscle
what structure comes out of he transversus abdominis?
deep inguinal ring (spermatic duct/vessels in males, ligament teres in females)
what is the sensory innervation for the inguinal canal?
ilioinguinal nerve
what is the motor innervation for the inguinal canal?
genital branch of genitofemoral nerve
where does an indirect hernia happen?
at the deep inguinal ring
where does a direct inguinal hernia happen?
superficial inguinal ring
does the abdominal contents enter the scrotum in indirect inguinal hernia?
yes, abdominal contents enter the scrotum in the males and into groin in females
does abdominal contents enter the scrotum in direct inguinal hernia?
no, abdominal contents never enter the scrotum
what is the most common abdominal hernia?
indirect inguinal hernia (75%)
how does on get an indirect inguinal hernia?
can be congenital or acquired
how does one get a direct inguinal hernia?
all acquired but can be predisposed
where does a direct hernia have weakness?
weakness of abdominal wall at Hesselbach’s (inguinal) triangle
what is an umbilical hernia?
abnormal closure after birth
what is a post-surgical/incisional hernia?
happens mainly after laparotomy/laparoscopy
artificially weakened anterior abdominal wall
what is a diastasis recti?
separation of linea alba
generally not a hernia but internal organs can push outward when intra-abdominal pressure increases
who does diastasis recti normally happen to?
happens equally in both genders
can happen to pregnant women
what worsens diastasis recti?
increasing intra-abdominal pressure
what are the layers of the thoracolumbar fascia?
anterior layer: internal oblique, transversus abdominis
middle layer: quadratus lumborum
posterior layer: erector spinae/extrinsic back muscles
how are the arcuate ligaments formed?
by tendinous structures of diaphragm, wrapping muscles and aorta
where is the median arcuate ligament located?
aortic hiatus - abdominal aorta
what is median arcuate ligament syndrome?
compression of aorta
which causes pain around stomach and leads to being afraid of eating
where is the medial arcuate ligament located?
psoas major
where is the lateral arcuate ligament located?
quadratus lumborum
what are the three arcuate ligaments?
median, medial, lateral
– compare to abdominal folds in anterior wall
where do the ventral rami L1-L4 exit?
between quadratus lumborum and psoas major
what is the anterior core muscle?
transversus abdominis - active all the time without activity specificity
what is the posterior core muscle?
multifidi - possible contribution of psoas major
what does proximal stability mean?
if your core is stable, movement in your distal joints are better. Thus, if you have good stability, you’re less likely to be injured
what is hyperlordosis?
too much lumbar lordosis
- over stretch transversus abdominis, resulting in weakness
what is flat back?
too little lumbar lordosis
- compromised shock absorption through the back
