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