Download Intercostal Muscles

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Boundaries:
superior –incisura jugularis, clavicle, acromion, spina scapulae
and proc. spinosus of C7
inferior – proc. xiphoideus, costal arch,
XI and XII rib to proc. spinosus of T12
Posterior axillary line divides it:
Pectus, chest
Dorsum, back
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1
2
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Regions:
1.
2.
3.
Regio infraclavicularis
Regio mammalis
Regio axillaris
3
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The axilla is the region
between the pectoral
muscles, the scapula, the
arm, and the thoracic
wall.
It is a region of passage
for vessels and nerves
that course from the root
of the neck into the upper
limb.
Axillary vessels and their
branches
Lymph nodes –
pectoral
lateral
subscapular
central
apical
Brachial plexus
– branches
- n. intercostobrachialis
Axillary vessels and their
branches
Lymph nodes –
pectoral
lateral
subscapular
central
apical
Brachial plexus
– branches
- n. intercostobrachialis
Axillary vessels and their
branches
Lymph nodes –
pectoral
lateral
subscapular
central
apical
Brachial plexus
– branches
- n. intercostobrachialis
Axillary vessels and their
branches
Lymph nodes –
pectoral
lateral
subscapular
central
apical
Brachial plexus
– branches
- n. intercostobrachialis
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Surface Anatomy:
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Skin
Subcutaneous tissue
Pectoral fascia
Muscles
Thoracic cavity
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Surface Anatomy:





Skin
Subcutaneous tissue
Pectoral fascia
Muscles
Thoracic cavity

-
Skeleton of the thorax
Sternum
Ribs
Vertebrae
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
-
The thoracic skeleton forms the
thoracic cage, which protects the
thoracic viscera and some abdominal
organs.
The thoracic skeleton includes:
Sternum
Ribs
Vertebrae

Intercostal Spaces - three layers of muscle
fill the intercostal space
Intercostal Muscles:
external intercostal muscle,
internal intercostal muscle,
innermost intercostal muscle.
m. transversus thoracis
subcostal muscles
Intercostal Muscles:
external intercostal muscle,
internal intercostal muscle,
innermost intercostal muscle.
m. transversus thoracis
subcostal muscles
Intercostal Muscles:
external intercostal muscle,
internal intercostal muscle,
innermost intercostal muscle.
m. transversus thoracis
subcostal muscles
Intercostal Muscles:
external intercostal muscle,
internal intercostal muscle,
innermost intercostal muscle.
m. transversus thoracis
subcostal muscles
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
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•
•
Intercostal spaces – 11. The interval
between adjacent ribs.
Structures in the intercostal space:
Intercostal v.
Intercostal a.
Intercostal n.
There are two neurovascular bundles:
- Posterior –post. intercostalis a., v. and intercostal n.
- Anterior –ant. intercostal a., v. and intercostal n.
They are connected at
the midclavicular line.

The anterior rami of nerves T1-T11 form the intercostal
nerves that run along the extent of the intercostal
spaces.
Herpes zoster
-
The diaphragm is a double-domed,
musculotendinous partition separating the
thoracic and abdominal cavities.
– central tendon
– muscular part
muscular part is divided
into three parts :
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

Sternal part
Costal part
Lumbar part
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•
•
•
•
Lumbar part
right crus
left crus
lig. arcuatum mediale
lig. arcuatum laterale

•
Costal part
trigonum lumbocostale

•
Sternal part
trigonum sternocostale
Diaphragmatic apertures:
•
•
•
–
–
small apertures in each crus
sternocostal triangle
caval opening
esophageal hiatus
aortic hiatus
Diaphragmatic apertures:
•
•
•
–
–
small apertures in each crus
sternocostal triangle
caval opening
esophageal hiatus
aortic hiatus
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•
•

Actions of diaphragm
only the domes of the diaphragm descend
increases intra-abdominal pressure
Innervation
phrenic nerves * (C4,
and C3, C5)
–
*
*
Includes :

Organs
• the primary organs of the
respiratory and
cardiovascular systems
 Vessels
• blood vessels
• lymph nodes

Nerves
• somatic
• autonomic

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
The thoracic cavity is divided into three major
spaces:
the right and left
pulmonary cavities
housing the lungs.
mediastinum that
houses the thoracic
viscera

Pleura – serous membrane. Each lung is invested by
and enclosed in a serous pleural sac.
Pleura consists of two continuous membranes:
the parietal pleura, which lines the pulmonary cavities
the visceral pleura, which invests all surfaces of the lungs forming
their shiny outer surface
The pleural cavity
• the potential space between
the layers of pleura
• contains a capillary layer of
serous pleural fluid
Parietal pleura consists of three parts:
– costal part
– diaphragmatic part
– mediastinal part

– pleural cupula
The potential pleural spaces:
costodiaphragmatic recesses
• costomediastinal recesses
• phrenicomediastinal recesses
• interlobar recesses
•
Inspiration
Expiration
If a penetrating wound opens
through the thoracic wall or
the surface of the lungs, air
will be sucked into the
pleural cavity because of the
negative pressure and the
lung will collapse.
Mediastinum – the region between the two pleural
cavities.
The boundaries of the mediastinum are:
superior - superior thoracic aperture
― inferior – diaphragm
― anterior - sternum
― posterior - bodies of vertebrae T1 to T12
― lateral – mediastinal pleurae (left and right)
―
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•
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The mediastinum is divided into four
parts:
superior mediastinum
inferior mediastinum
– anterior
– middle
– posterior
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–
–
–
Structures are distributed into three
groups:
retrosternal
intermediate
prevertebral
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–
–
–
Retrosternal group includes:
lymph nodes
thymus
brachiocephalic veins
superior vena cava
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–
–
–
Retrosternal group includes:
lymph nodes
thymus
brachiocephalic veins
superior vena cava
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–
–
Intermediate group:
Aortic arch and its branches
Vagus nerves (right and left)
– Left recurrent laryngeal nerve
–
–
Phrenic nerves (right and left)
Plexus cardiacus - rami and
nervi cardiacae
*
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–
–
Intermediate group:
Aortic arch and its branches
Vagus nerves (right and left)
– Left recurrent laryngeal nerve
–
–
Phrenic nerves (right and left)
Plexus cardiacus - rami and
nervi cardiacae
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–
–
–
–
Prevertebral group:
trachea
esophagus
tracheal and tracheobronchial lymph nodes
thoracic duct
The anterior mediastinum, the smallest subdivision of the
mediastinum, lies between the body of the sternum and the
pericardium posteriorly. It consists of:
‒ loose connective tissue
– sternopericardial ligaments
– internal thoracic a. and its branches
– lymph nodes – sternal and diaphragmatic
– thymus – inferior part (in children)

The pericardium and its contents (heart and roots of its
great vessels) constitute the middle mediastinum.
heart
– ascending aorta
– pulmonary trunc
– superior vena cava
– inferior vena cava
– pulmonary arteries
– phrenic nerves
– pericardiacophrenic a.
–
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The pericardium is a fibroserous membrane that
covers the heart and the beginning of its great vessels.
It is a closed sac composed of two layers.
• parietal layer, fibrous pericardium
• visceral layer, epicardium
The serous pericardium is composed
mainly of mesothelium.
The pericardial cavity is the potential
space between opposing layers of the
parietal and visceral layers of serous
pericardium.

The visceral layer extends onto the beginning of the great
vessels, becoming continuous with the parietal layer of
serous pericardium.
1) where the aorta and pulmonary
trunk leave the heart - porta arteriosa
2) where the SVC, inferior vena cava
(IVC), and pulmonary veins enter the
heart - porta venosa
The pericardial reflection
surrounding them forms
recesses:
 transverse pericardial sinus
oblique pericardial sinus

The visceral layer extends onto the beginning of the great
vessels, becoming continuous with the parietal layer of
serous pericardium.
1) where the aorta and pulmonary
trunk leave the heart - porta arteriosa
2) where the SVC, inferior vena cava
(IVC), and pulmonary veins enter the
heart - porta venosa
The pericardial reflection
surrounding them forms
recesses:
 transverse pericardial sinus
oblique pericardial sinus
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
The posterior mediastinum is located posterior to the
pericardium, anterior to the T5-T12 vertebrae.
It contains:
- esophagus
- thoracic aorta
- azygos vein
- hemiazygos vein
- thoracic duct
- vagus n.
- splanchnic nerves
- lymph nodes


The posterior mediastinum is located posterior to the
pericardium, anterior to the T5-T12 vertebrae.
It contains:
- esophagus
- thoracic aorta
- azygos vein
- hemiazygos vein
- thoracic duct
- vagus n.
- splanchnic nerves
- lymph nodes


The posterior mediastinum is located posterior to the
pericardium, anterior to the T5-T12 vertebrae.
It contains:
- esophagus
- thoracic aorta
- azygos vein
- hemiazygos vein
- thoracic duct
- vagus n.
- splanchnic nerves
- lymph nodes


The posterior mediastinum is located posterior to the
pericardium, anterior to the T5-T12 vertebrae.
It contains:
- esophagus
- thoracic aorta
- azygos vein
- hemiazygos vein
- thoracic duct
- vagus n.
- splanchnic nerves
- lymph nodes


The posterior mediastinum is located posterior to the
pericardium, anterior to the T5-T12 vertebrae.
It contains:
- esophagus
- thoracic aorta
- azygos vein
- hemiazygos vein
- thoracic duct
- vagus n.
- splanchnic nerves
- lymph nodes


The posterior mediastinum is located posterior to the
pericardium, anterior to the T5-T12 vertebrae.
It contains:
- esophagus
- thoracic aorta
- azygos vein
- hemiazygos vein
- thoracic duct
- vagus n.
- splanchnic nerves
- lymph nodes