3 Abdominal Wall Flashcards
abdomen
region of trunk btwn diaphragm + pelvic inlet/brim
posterior border of abdomen
lumbar vertebrae/discs
12th ribs
upper body pelvis w/ psoas y quadratus lumborum muscles
anterior border of abdomen
lower thoracic wall
external abdominal oblique
internal abdominal oblique
transversus abdominis
subdivisions of abdominal wall
anterior
posterior
anterolateral
left lateral (flank)
anteroleateral abdominal wall bounded by
7th - 10th costal cartilages
xiphoid process
inguinal ligament
pelvic girdle
anteroleateral abdominal wall contains
skin superficial fascia (hypodermis) muscles/aponeuorsis (deep fascia) extraperitoneal fat parietal peritoneum
**Smiles Stay Fake Mainly to Entertain Foreign Pricks Passing by
fascial linings
superficial fascia
deep fascia
endoabdominal (transversalis) fasic
superficial fascia
subcutaneous tissue (hypodermis) - fatty and membranous layers
deep fascia
dense connective tissue that covers the abdomen
- separates the 3 muscles layers
endoabdominal (transversalis) fascia found between
(1) extraperitineal fat
(2) parietal peritneum
(3) transversalus abdominis muscle
endoabdominal (transversalis) fascia facts
- name changes according to structures it overlies (diaphragmatic, pelvic, etc)
- loose areolar tissue
endoabdominal (transversalis) fascia contains
(1) blood vessels
(2) lymphatic structures
**no nerves
anterior abdominal wall muscles
external abdominal oblique internal abdominal oblique transversus abdominis rectus abdominis pyramidalis
external abdominal oblique
**anterior abdominal wall muscle
O: external surface of ribs 5 – 12
I: linea alba +pubic tubercle + anterior iliac crest
A: compress y support abdominal viscera + flex y rotate trunk
N: thoracoabdominal nerves
subcostal nerve
\ //
internal abdominal oblique
**anterior abdominal wall muscle
O: thoracolumbar fascia + anterior iliac crest + inguinal ligament
I: inferior border of lower ribs 10 – 12 + linea alba
A: compress y support abdominal viscera + flex/rotate trunk
N: thoracoabdominal nerves + L1 – L2
// \
transversus abdominis
**anterior abdominal wall muscle
O: inferior surface of costal cartilages 7 – 12
iliac rest
inguinal ligament
I: aponeurosis of internal abdominal oblique
lina alba
A: compress & support abdominal viscera
N: thoracoabdominal nerves + L1 – L2
= =
rectus abdominis
**anterior abdominal wall muscle
O: pubic crest + symphysis
I: xiphoid process + costal cartilages 5 – 7
A: flex trunk compress + abdominal viscera + stabilize tilt of the pelvis
N: thoracoabdominal nerves
only muscle that flex/rotates trunk b/c it runs obliquely
(aka) antilordosis muscle
clinical application of abdominal muscles
(infants) abdominal muscles not as developed, therefore they have round, pudgy bellies
(preggo) abdominal muscles separate
- lordosis causes back problems
pyramidalis
**anterior abdominal wall muscle
O: pubic crest
I: linea alba
A: draw down on linea alba (aid in expiration)
N: thoracoabdominal nerves
absent in 20% of population
located inside rectus sheath
joint action EAO + IAO + TA + RA
antagonizes diaphragm
- helps w/ forced expiration
left rotation uses right EAO + left IAO
clinical application of pyramidalis
pyramidalis = surgical landmark to determine midline and linea alba
- esp. in C-sections
rectus sheath
woven aponeuroses from EAO, IAO, TA
- contains V.A.N.
- relations differ depending upon if above or below arcuate line
arcuate line
collection of fascia that is very strong and thick where fascia is suddenly in front of the abdominal muscles
innervation of anterolateral walls
I: ventral rami (T7 - L1)
travels between IAO + TA
supplies skin, abdominal wall, and peritoneum
L1 nerves
illiohypogastric nerve
ilioinguinal nerve
inguinal region
region that extends from anterior superior iliac spine (ASIS) to the pubic tubercle
- includes inguinal ligament y inguinal canal
inguinal ligament
inferiormost part of external abdominal oblique aponeurosis
- equivalent of retinacula
retinacula
band of connective tissue that covers tendon
inguinal canal
parallel and superior to medial 1/2 inguinal ligament
- pathway = oblique (rings do not overlap)
inguinal canal contains
spermatic cord (males)
round ligament (females) - only connective tissue for filter
blood y lymph vessels
ilioinguinal nerve
development of inguinal canal
when testes descend, they pass between EAO and IAO into scrotum where cremaster muscle is formed
- cremaster muscle derived from IAO
- grabs muscles from IAO to make cremaster muscle of scrotum
rings found in inguinal canal
deep (internal) inguinal ring
superficial (external) inguinal ring
deep (internal) inguinal ring
ENTRANCE to canal
- outpocketing of transversalis fascia
superficial (external) inguinal ring
EXIT to canal
- split in aponeurosis of EAO
structural weakness of inguinal area
increased intra-abdominal pressure forces deep (internal) wall of inguinal canal against superficial (external) wall of inguinal canal
- contractions strengthen wall
- muscle weakness leads to inguinal hernia
inguinal hernia
abdominal viscera protrudes through abdominal wall
90% = protrusion of parietal peritoneum and abdominal viscera thru a normal or abnormal opening
types of inguinal hernias
acquired (direct) inguinal hernia
congenital (indirect) inguinal hernia
acquired (direct) inguinal hernia
enters directly thru abdominal wall (medial to inferior epigastric vessels)
- cause: deep (internal) abdominal wall weakness
- enters canal mid-path and runs PARALLEL to spermatic cord
**more common in males
NEXT TO CANAL
congenital (indirect) inguinal hernia
enters deep ring (lateral to inferior epigastric vessels) and exits superficial ring
- crosses whole canal within spermatic cord
- affects males and females equally
**most common (2/3)
DIRECTLY THROUGH CANAL
parts of the posterior abdominal wall
L1-L5 vertebrae Muscles: psoas, iliacus, quadratus lumborum diaphragm (superior part of wall) thoracolumbar fascia` fat, nerves, vessels
quadratus lumorum
**posterior abdominal wall muscle
SA: 12th rib lumbar transverse processes
IA: internal iliac crest
A: flex trunk + laterally fix 12th rib during respiration
N: T12 + L1 – L4
arcuate ligaments of diaphragm cross in front of anterior surface of quadratus lumborum
abdominal dermatome T7
tip of xiphoid process
abdominal dermatome T10
umbilicus
abdominal dermatome L1
inguinal ligaments + pubic symphysis
