Abdominal Wall Flashcards
What structures can be found at L1
Transpyloric plane: 1st part of duodenum, 8th intercostal space, superior mesenteric artery
What structures can be found at L2
Renal artery, L diaphragm crus attachment.
What internal structures can be found at L3
Subcostal plane
12th rib and inferior mesenteric arteries
What internal structure can be found at L4
Supracristal plane
Umbilicis
Abdominal aorta divides into R and L common iliac a
What internal structures can be found at L5
Intertubercular plane, IVC formed by R/L common iliac v
Where does the median sagittal plane run
Xiohoid process to pubic symphysis
What are the contents of the R upper and lower quadrants
R upper- liver and duodenum
R lower- cecum, ascending colon, McBurney’s point
What are the contents of the L upper and lower quadrants
L upper- stomach and spleen
L lower- descending and sigmoid colon
What is the appendix referral point
McBurney’s point
Referred pain from appendix
Where does the midclavicular plane run
Mid clavicle to mid inguinal ligament in the sagittal plane
What is the more reasonable plane for the stomach region
Transpyloric L1
What is the innervation of the posterior abdominal wall
Dorsal rami of spinal nerves
What is the innervation of the lateral abdominal wall
Intercostal nerves- lateral cutaneous branch
What is the innervation of the anterior abdominal wall
Intercostal nerve- anterior cutaneous branch
What is a common impingement of the T6-7 lateral cutaneous nerve
Serratus anterior can impinge
Secondary to shoulder problems
Need to work back muscles
What nerve level corresponds to the xiohoid process
T6
What nerve level innervates the umbilicus
T10
What nerve level innervates to ASIS
T12
How is the dermatome of the abdomen correlated
They are not.
Spinal cord stops at T12-L2 so nerves travel inferior to the exiting level
T9 spinal nerve innervate transversely at L3 vertebral level
What is the blood supply of the lateral abdominal wall
Posterior intercostal vessels
What is the blood supply of the anterior abdominal wall
Superior and inferior epigastric vessels, deep and superficial circumflex iliac artery
Anastomosis of superior and inferior epigastric vessels
What if there is an abdominal aorta malfunction
LE can get blood from superior epigastric artery
What happens if there is an IVC malfunction
LE can drain back to the SCV
Portal hypertension=Caput medusae
Swollen superficial veins in abdomen to compensate
What are the 9 layers of the abdominal wall?
Skin Superficial fascia: fatty layer and membranous layer External oblique Internal oblique Transverse abdominus Transversalis fascia Extraperitoneal fascia Parietal peritoneum
How are the external oblique muscle fibers oriented
Hands in pocket
What is the muscle fiber orientation of internal oblique
Oh my
What is the muscle fiber direction of transversus abdominis
Horizontal muscle fiber
CORE muscle
Why is the transverse abdominus considered a CORE muscle
Muscle fibers interdigitate with diaphragm
Weave together
Where do the intercostal nerves run in the abdominal muscles
Between the transverse abdominus and internal oblique
What is the pyramidalis
Small triangular muscle in the distal anterior recuts abdominis
Doesn’t exist in all people or even on both sides
What is significant about the attachment of the recuts abdominus
As it narrows down to a point and forms a weak point on the anterior abdominal wall
What is the rectus sheath
Recuts abdominus is wrapped by an aponeurosis is of 3 muscles
What is the arcuate line
1/3 distance from umbilicus to pubic symphysis of posterior rectus abdominus
What is above the arcuate line
Superficial- 1 EO, .5 IO
Deep- .5 IO, 1 TA
What is below the arcuate line
Superficial- all 3 muscles
Deep- none, weakness of abdominal wall
What is the purpose of aponeurosis fiber crossing
Improves strength and functions
Weaving of both superficial and deep layers of the same aponeurosis
What is intramuscular exchange
Fiber crossing between 2 layers of the same oblique
What is the inter muscular exchange
Fiber crossing between 2 layers of different obliques
What is line alba
Midline of aponeurosis fiber exchange
What is the lateral umbilical fold
Inferior epigastric vessels
What is the medial umbilical fold
Remnant umbilical artery
What is the median umbilical fold
Remnant allantois (urachus), from umbilicus to suspend the urinary bladder
What are the borders for hesselbachs triangle or inguinal triangle
Lateral- medial side of lateral fold
Inferior- inguinal ligament
Medial- lateral rectus abdominus
***very weak, common spot for hernia
What stage of gestation is the placenta completed
3 weeks
Functions of placenta
Nutrient and oxygen exchange with mothers blood
No direct contact with fetus
What is the umbilical cord
Connection from fetus with placenta
Remnant structures after birth
Contains blood vessels/urachus
What do the umbilical arteries become
Start: 2 internal iliac arteries
End: 2 medial umbilical ligaments/folds
What do the umbilical veins become
Start: veins to the liver and then IVC (ductus venosus)
End: ligament teres and ligament venosum
What is the allantois and what does it turn into
Start: fetal urine drainage
End: median umbilical ligament/ fold
What is the ductus arteriosus and what does it become
Start: bridging blood vessels between the aorta and pulmonary trunk
End: ligament arteriosum
What are the esophageal varices
Anastomosis of portal vein branches to the esophageal veins to SVC
What are the causes of internal hemorrhoids
Anastomosis of rectal vein to IVC
What causes caput medusae
Portal hypertension
Anastomosis with epigastric veins to IVC or SVC if IVC has problems too
Paraumbilical veins can reopen during portal hypertension
What are the layers of inguinal ligament
External oblique
Internal oblique
Transverse abdominus
What does the external oblique form in the inguinal ligament
Distal part forms inguinal ring
What does the internal oblique form in the inguinal ligament
Cremaster muscle
What does the transverse abdominis form in the inguinal ligament
Deep inguinal ligament- spermatic duct in males and ligament teres in females
What is the innervation if the inguinal ligament/canal
Motor: genital branch of genitofemoral n
Sensory: ilioinguinal n
What is an indirect inguinal hernia
Hernia happens at the deep inguinal ring
Most common hernia 75%
Abdominal contents enter scrotum in males and groin in females
Can be congenital or acquired
What is the direct inguinal hernia
Hernia that happens at the superficial inguinal ring
Weakness of abdominal wall in hesselbachs triangle
Abdominal contents NEVER enter scrotum
All are required, but some individuals can be predisposed
What is an umbilical hernia
Abnormal closing after birth
What is a post surgical/incisional hernia
Mainly after a laparotomy or laparoscopy
Artificially weakened anterior abdominal wall
What is the diastasis recti
Separation of linea alba
Happens equally in both genders
Not a hernia, but internal organs push outward when intra abdominal pressure increases but returns afterwards
**must design exercises accordingly
What muscles attach to the anterior layer of the thoracolumbar fascia
Internal oblique and transverse abdominis
What muscles attach to the middle layer of the thoracolumbar fascia
Quadratus lumborum
What muscles attach to the posterior layer of the thoracolumbar fascia
Erector spinal and extrinsic back muscles
What are the posterior arcuate ligament formed by
Tendinous structure of diaphragm, wrapping muscles, and aorta
Where is the posterior median arcuate ligament
Aortic hiatus; a round abdominal aorta
What is median arcuate ligament syndrome
Compression of aorta, pain around stomach, afraid to eat
Where is the medial arcuate ligament on the posterior abdominal wall
Over psoas major
Where is the lateral arcuate ligament from the posterior abdominal wall
Over quadratus lumborum
Where do the ventral rami of L1-4 exit
Between quadratus lumborum and psoas major
Where is the Subcostal n
T12, under 12th rib
Where is the iliohypogastric n
T12/L1 above ASIS
Where is the ilioinguinal n
L1, follows inguinal canal
Where is the lateral femoral cutaneous n
L2-3 under inguinal ligament
Where is the femoral n
Lateral and deep to psoas major L2-4
Where is the genitofemoral n
L1-2 crossing psoas major
Genital branch follows inguinal canal
Femoral branch follows femoral triangle
Where is obturator n
L2-4 medial and deep to psoas major
Where is the lumbosacral trunk
L4-5 deep to obturator
Which anterior core muscles contribute to stability of core
Transverse abdominis- active all the time
Possible contribution of internal oblique through thoracolumbar fascia
Which posterior muscles contribute to core stability
Multifidi and psoas major
Help maintain lordosis
What is hyperlordosis
Too much extension in lumbar spine
Weakness in transverse abdominis
What causes flat back
Too little lordosis in lumbar
Compresses shock absorption
What nerves innervate quadratus lumborum
Ventral rami spinal nerves
What nerves innervate the internal oblique and cremaster muscle
IO- iliohypogastric
C- ilioinguinal
