Session 32
Objectives

 Describe the bony structure of the thoracic cage
 Describe the structure of the musculature and
neurovasculature of the thoracic and abdominal
walls
 Analyze the functions of the walls of the thorax and
abdomen
 Discuss how the structure and function of these
walls apply to common dysfunctions
Bony structure review


Running in the costal groove:
• intercostal artery & vein
(from supreme intercostal &
internal thoracic)
• intercostal nerve
(from anterior rami)
Bony structure review

Joints of the thorax


Intercostals

 External Intercostal (hands in pockEts)
 Internal Intercostal (hands on tIts)
 Innermost Intercostal (same as internal)
Right or Left?
Cross section


Intercostal membranes and
Transversus thoracis

A patient with a stab wound through
the thoracic wall medial to the
midclavicular line will have damage
to which structures?
ac
i
an
sv
e
Tr
er
co
lI
nt
na
In
te
r
rs
us
st
al
m
Th
or
us
cl
us
cl
lm
rc
os
ta
In
te
rn
al
Ex
te
33%
e
e
A. External
Intercostal muscle
B. Internal Intercostal
muscle
C. Transversus
Thoracis
33%
s
33%
Endothoracic fascia,
parietal pleura, visceral pleura

 Pleura – serous membrane inside the thorax
 Parietal pleura – superficial
 Visceral pleura – deep and on the lungs
 Pleural cavity – space between parietal and visceral
pleura
 Right and Left pleural cavities are separated by the
mediastinum
A patient with R
pneumothorax will be unable
to breathe because both lungs
will be affected.
50%
50%
se
Fa
l
Tr
ue
A.True
B. False
Abdominal wall –
superficial fascia

 Camper’s fascia – contains fatty tissue
 Scarpa’s fascia – membranous layer between
camper’s fascia and abdominal muscles
Oblique and Transverse
Abdominus

 External oblique – continuation of external
intercostal (hands in pockEts)
 Internal oblique – continuation of internal intercostal
(hands on tIts)
 Tranverse oblique – horizontal fibers, function to
increase intra-abdominal pressure
 Posteriorly, all start around the scapular line
 Anteriorly, all insert at the rectus sheath
(midclavicular line)

Rectus Abdominus


Rectus sheath vs.
Transversalis fascia

 Rectus abdominus is embedded within the rectus sheath
above the arcuate line (between the 2 halves of the
internal oblique aponeurosis)
 Rectus abdominus is between the rectus sheath and the
transversalis fascia below the arcuate line (posterior to the
transverse abdominus aponeurosis
Above or
below arcuate
line?
Extraperitoneal
fascia
What is immediately posterior
to Rectus Abdominus above
the arcuate line?
Tr
A. Transversalis fascia
B. Aponeurosis of
internal oblique
C. Aponeurosis of
transverse abd.
D. Parietal peritoneum
an
sv
Ap
er
sa
on
lis
eu
fa
ro
sc
s is
ia
of
in
Ap
te
on
rn
eu
al
ro
o.
s is
..
of
tra
ns
ve
rs
Pa
...
r ie
ta
lp
er
it o
ne
um
25% 25% 25% 25%
Inguinal Canal

Myopectineal Orifice

 Deep to inguinal ligament
 Weakest area of abdominal
wall
Anterior Abdominal wall –
Posterior view

Peritoneum

 Parietal peritoneum
 Visceral peritoneum
 Peritoneal folds
 Omentum
 Mesentery
 Intra-peritoneal
organs vs. Retroperitoneal organs
The peritoneal cavity:
33%
ta
l
ie
it h
ns
ta
i
Co
n
Is
b
et
w
ee
n
th
e
th
e
ab
pa
r
w
ed
fil
l
ce
sp
a
Is
a
33%
al
...
p.
..
flu
id
33%
do
m
in
A. Is a space filled
with fluid
B. Is between the
parietal peritoneum
and transversalis
fascia
C. Contains the
abdominal organs
Inguinal hernias are most
likely to severely damage the
femoral nerve
Tr
se
ue
A.True
B. False
50%
Fa
l
50%
Objectives

 Describe the bony structure of the thoracic cage
 Describe the structure of the musculature and
neurovasculature of the thoracic and abdominal
walls
 Analyze the functions of the walls of the thorax and
abdomen
 Discuss how the structure and function of these
walls apply to common dysfunctions