Abdominal Wall Flashcards
What nerves innervate the abdominal wall
Dorsal rami of spinal nerves and ventral rami of spinal nerves
What ventral rami of spinal nerves innervate the anterolateral wall?
Lateral cutaneous branch, anterior cutaneous branch, muscular/collateral branch
Where is the T4 segmental distribution?
T4 - nipple line
Where is the xiphoid process
T6
Where is the umbilicus?
T10
Which side of the body do spinal nerves run lower?
anteriorly
T9 runs posteriorly at T9 disc level and anteriorly at L3 level
Caval opening is at which vertebral level?
T8
What is abdominal aorta malfunction?
Lower extremity gets blood supply from superior epigastric artery
What is the inferior vena cava malfunction?
Lower extremity blood can drain back to superior vena cava
What vessels supply the lateral abdominal wall?
Posterior intercostal/subcostal/lumbar arteries
What vessels supply the anterior abdominal wall?
Superior and inferior epigastric arteries, deep and superficial circumflex iliac artery
How many layers of the abdominal wall are there?
9
What order do the layers of the abdominal wall go from superficial to deep?
skin
superficial fascia
fatty layer (camper’s fascia)
membranous layer (scarpa’s)
external oblique
internal oblique
transversus abdominis
transversalis fascia
extraperitoneal fascia
parietal peritoneum
What happens during herniation?
abdominal contents will push through the different layers of the structures which make up the abdominal wall
Where are the external oblique muscles?
the external surface of the 5th through 12th ribs, deeper to the costal head of pectoralis major to the linea alba, iliac crest, pubic tubercle. It folds to form the inguinal ligament
What innervates the external oblique muscles?
intercostal nerves T7-T11 and subcostal nerve T12
What is the muscle fiber direction of the external oblique muscles?
Same as external intercostals, “hands into pockets”
What is the blood supply to the external oblique muscles?
Intercostal arteries
What actions do the external oblique perform?
B contraction: trunk flx
unilateral contraction: ipsilateral SB and contralateral RT to the left and right
What happens during closed chain motions?
Axial skeleton approaches the appendicular skeleton
Internal oblique muscles origin and insertion
Inferior border of 10th through 12th ribs, thoracolumbar fascia
linea alba, anterior 2/3 of iliac crest, continuous as part of the cremaster muscle
what innervates the internal oblique muscles?
Intercostal nerves T7-T11/ subcostal nerve T12, iliohypogastric, genital branch of genitofemoral nerve
What supplies blood to the internal oblique muscles?
Intercostal arteries
What is the function of the internal oblique muscles?
Support abdominal contents and stabilize pelvis
What does the internal oblique do?
Bilateral contraction - trunk flexion
Unilateral contraction - ipsilateral SB and RT, elevate testes
What are the attachments of the transversus abdominis?
Thoracolumbar fascia and inner surface of ribs 7-12
Linea Alba, iliac crest, pubic tubercle, folds to form inguinal ligament
What is the direction of the muscles fibers in transversus abdominis?
Horizontal muscle fibers interdigit with diaphragm
What is the innervation of the transversus abdominis?
Intercostal nerves T7-T11 and subcostal nerve T12, branches of L1
Where do intercostal nerves run?
Between transversus abdominis and internal oblique muscles
What is the function of the transversus abdominis?
Increase intrabdominal pressure (compression) and ipsilateral rotation, stabilize the spine
What is the rectus abdominis also known as?
6 pack
Distal attachment of which muscle narrows down and forms a weak point on the anterior abdominal wall ?
Rectus abdominis
small triangular muscle in the distal anterior rectus abdominis, not exist in all the people, nor exist in both sides
Pyramidalis
Rectus abdominis: Innervation?
Intercostal nerves T7-T11 and subcostal nerve T12
Rectus abdominis function
compression, stabalizes the abdomen, trunk flexion
Superior epigastric artery is a continuous branch of which artery?
Internal thoracic mammary artery (branch of subclavian artery)
Aponeruosis fiber crossing does what?
improving the strength and functions, superficial to deep
- Between 2 same layer oblique: intramuscular exchange
- Between opposite external and internal oblique: intermuscular exchange
Linea alba: the midline of the aponeurosis fiber exchange. True or False?
True
Rectus abdominis is wrapped by what?
A Aponeurosis of the 3 abdominal muscles
Arcuate line is where?
1/3 distance of umbilicus to pubic symphysis of posterior rectus abdominis
Where is there a weakness of the abdominal wall?
deep to rectus below the arcuate line
Where are all aponeuosis of 3 layers of muscles
Superficial to rectus below arcuate line
Where is the aponeurosis of the external oblique?
Superficial to rectus above arcuate line
Where is the aponeurosis of transversus abdominis?
Above arcuate line deep to rectus
Half of which muscle’s aponeurosis is superficial to rectus and half is deep to rectus?
Internal oblique
When is the placenta completed?
3rd week of gestation
There is no direct exchange of mother and baby’s blood. true or false?
True
How is the embryo/fetus connected to the placenta?
Umbilical cord
Umbilical arteries become what after birth?
Umbilical ligaments/folds
Umbilical vein becomes what after birth?
ligament teres and ligamentum venosum
Allantois becomes what after birth?
Medial umbilical ligament/fold
Foramen ovale becomes what after birth?
Fossa Ovalis
What structure may not fully close after birth and cause no harm?
Fossa ovalis
Ductus arteriosus becomes what after birth?
Ligamentum arteriosum
A patient tore the right internal oblique muscle fully during MVA. Which motion will be compromised?
Side bend and rotation
Hesselbach’s triangle (inguinal triangle) boundaries:
Lateral: medial of lateral umbilical fold
Inferior: inguinal ligament
Medial: lateral rectus abdominis
What is portal hypertension?
Liver pathology blocks portal vein flow through
- Anastomosis with rectal vein to IVC: internal hemorrhoids (1/6 but with severe bleeding)
- Anastomosis of portal vein branches to esophageal veins: esophageal varices
- Anastomosis with superficial epigastric veins to IVC: caput medusa
What veins close after birth and reopen in portal hypertension?
Paraumbilical veins
Whats the difference between portal hypertension and IVC obstruction?
superficial abdominal veins to SVC, not around umbilicus exactly
inguinal ligament is:
External oblique aponeurosis spanning ASIS and pubic tubercle
Inguinal canal is made up of?
Layers of abdominal muscle
external oblique - forms superficial/external inguinal ring
internal oblique - forms cremaster muscle to form spermatic cord in the males
Transversus abdominis - forms deep/internal inguinal ring
Innervation of the inguinal canal?
Genital branch of genitofemoral nerve (motor) and the ilioinguinal nerve (sensory)
How many degrees less than the internal temperature do the testes need for sperm development?
2-3 degrees Celcius
Testes not descending is called what?
Cryptorchidism
What the reflex called that causes the testes to elevate in the scrotum?
Cremasteric reflex
Which muscles contribute their aponeurosis/tendon to form the rectus sheath above arcuate line?
external and internal oblique and transverse abdominis
Indirect inguinal hernia happens at the:
Deep inguinal ring
Indirect inguinal hernias are common in which gender?
Males
What is the most common type of abdominal hernia?
Indirect inguinal hernia
What is a direct or acquired inguinal hernia?
Happens at superficial inguinal ring due to weakness of abdominal wall (Hesselbach’s triangle)
Abdominal contents never enter the scrotum in which type of hernia?
Direct
Umbilical hernias cause:
Urine drainage 2/2 allantois not close to form urachus
Umbilical hernias are due to:
Abnormal closure of umbilicus after birth
Post surgical hernias happen mainly after what kind of surgery?
Laparotomy/laproscopy
Do all hernias increase risk of bowel obstruction?
Yes
Diastasis recti is a seperation of what?
linea alba
Does diastasis recti happen more in males or females?
Equally in both
Hernia and diastasis recti worsen with what?
Increasing intra-abdominal pressure
Which structure forms the medial umbilical fold?
remnant umbilical artery
Layers of the thoracolumbar fascia
- Anterior layer: internal oblique, transversus abdominis
- Between anterior and middle layer: quadratus lumborum
- Between middle and posterior layer: erector spinae
- Posterior layer: extrinsic back muscles
Quadratus lumborum is located where?
origin - Inferior border of 12th rib and lateral transverse process of L1~L4
insertion - Posterior iliac crest and iliolumbar ligament
Quadratus lumborum is innervated by”
Subcostal T12 and L1-L4 lumbar spinal nerves (ventral rami)
What are the functions of quadratus lumborum?
(B) Depress 12th rib to facilitate respiration
(Uni) ipsilateral lumbar SB and Hip lift
Psoas Major innervation
Femoral nerve (L2-L4), lumbar plexus
Psoas major proximal and distal attachments
TP, bodies, and discs of T12-L5
lesser trochanter
Motions of the Psoas Major?
Open chain: hip FLX/ER/ADD; Closed chain: trunk flexion (B)/ ipsilateral SB
Psoas minor exists in everyone. T/F?
False. Does not exist in all people not in both sides of the same person. VARIATION
A patient has been diagnosed direct inguinal hernia. Where does the herniation happen?
Superficial inguinal ring
What happens to someone with median arcuate ligament syndrome?
compression of aorta/celiac trunk, pain around stomach, afraid of eating
Arcuate ligaments are what?
Tendinous structures of diaphragm, wrapping muscles and aorta
Lumbar Plexus: Ventral rami of T12/L1~L4 exit between which two muscles?
Quadratus lumborum and psoas major
Does quadratus lumborum belong to an intrinsic back muscle? Ventral or dorsal rami of spinal nerves innervate this muscle?
No.
Ventral rami of spinal nerves
What plane of is at L1
transpyloric plnane
What plane is at L3?
Subcostal plane
What plane is at L5?
Intertubercular plane
What plane is at L4?
Supracristal/transumbilical plane
What is in the right upper quadrant?
Liver and duodenum
What is in the left upper quadrant?
Stomach and sleen
What is in the right lower quadrant?
Cecum and descending colon
What in in the left lower quadrant?
Descending and sigmoid colon
What is McBurney’s point?
Appendix referral pain
