THE THORAX:
Arterial The posterior intercostal artery runs between the internal and innermost intercostal
supply muscles and supplies the intercostal muscles, overlying skin and parietal pleura.
The anterior intercostal artery also supplies the same as above^
The internal thoracic artery passes between the costal cartilages and internal
intercostal muscles to divide into superior epigastric and musculophrenic arteries.
- The anterior intercostal arteries supply the intercostal spaces 1-6
- The musculophrenic arteries to intercostal spaces 7-9
Subcostal artery runs below the inferior border of 12th rib, it distributes to the
muscles of the anterolateral abdominal wall and overlying skin
Venous Anterior venous drainage is done by the anterior intercostal drains which drain
supply straight into the internal thoracic vein which branches off the subclavian vein,
deoxygenated blood finally returns to the heart
Posterior venous drainage is done by the posterior intercostal veins which drain into
the azygous vein on the right hand side = this vein connects the SVC to the IVC.
- At the arch of the azygous vein, it joins with the superior vena cava which
drains straight into the RA of the heart
- On the left side you have the hemi azygous and accessory azygous veins
which drain into the azygous veins
- The hemi azygous veins form as a combination of the last 9-12 posterior
intercostal veins
- Accessory azygous veins forms due to the union of posterior intercostal veins
at 4-8
- At T7/T8 the accessory azygous vein rains into the azygos vein and at T8/T9
the hemi azygous vein drains into the azygous vein
- This is them taken to the superior vena cava where the azygous vein drains
into
Nerve Typical intercostal nerves (3th-6th) – run across the internal surface of the internal
supply intercostal membrane and the muscle in the middle of the intercostal spaces
- When the nerves approach the angle of the ribs, they pass between the
internal intercostal and innermost intercostal muscles before continuing
inside of the costal grooves
- The intercostal nerves lie inferior to the intercostal arteries which are in turn
, are inferior to the intercostal veins
Atypical intercostal nerves (are the 1st, 2nd, 7th-11th)- intercostal nerves 1 and 2 pass
on the internal surfaces of the 1st and 2nd ribs instead of along the inferior margins of
the costal grooves
After giving rise to the lateral cutaneous branches, the 7th- 11th intercostal nerves
continue to supply the abdominal skin and muscles
Phrenic nerve = motor and sensory nerve of the diaphragm
Vagus nerve = provides parasympathetic supply for all the organs of the thorax and
abdomen
Intercostal nerves = direct continuation of the anterior rami of the thoracic spinal
nerves, this gives motor innervation to the intercostal muscles and sensory
innervation to the chest wall
Sympathetic trunk = runs alongside vertebral column to T1 down to the sacrum,
connections between sympathetic trunk and anterior rami of the spinal nerves =
rami communicantes
Lymphatic NONE NEEDED TO KNOW HERE
supply
THE BREAST
Arterial Medial mammary branches originating from the internal thoracic artery which in
supply turn originates from the subclavian artery – supplies the medial aspect of the breast.
Lateral aspect of the breast –
- Lateral mammary branches originating from the lateral thoracic artery which
originates from the axillary artery, originate from the posterior intercostal
arteries – derived from the aorta
(supply the lateral aspect of the breast in the 2nd 3rd and 4th intercostal spaces
, - Posterior intercostal artery branches – lateral cutaneous branch
- Mammary branch = originates from the anterior intercostal artery
- Pectoral branch from the thoracoacromial artery
Venous The venous drainage of the breast is mainly to the axillary vein, but there is some
supply drainage to the internal thoracic vein
- Drainage through the lateral mammary veins which drain into the lateral
thoracic vein and then the axillary vein
- Drainage through the medial mammary veins into the internal thoracic vein
Nerve Nerves of the breast derive from the anterior and lateral cutaneous branches of the
supply 4th to 6th intercostal nerves
These branches of the intercostal nerves pass through deep pectoral fascia covering
the pectoralis major to reach the skin, branches convey sensory fibres to the skin of
the breast and sympathetic fibres to the smooth muscle of the blood vessels in the
breast and overlying skin and nipple
Lymphatic Lymphatic drainage of the breast is important in its role of Metastasis of cancer, the
supply first stop if the subareolar lymphatic plexus, this is where the lymph first drains from
Lymph from the lateral quadrants:
- Axillary lymph nodes to the pectoral lymph node to the infra, supraclavicular
node to the subclavian lymphatic trunk
Lymph from medial quadrants:
- From parasternal lymph nodes to the broncho mediastinal trunks to the
thoracic duct, right lymphatic duct
75% of the lymphatic drainage of the breast is done to the axillary lymph nodes, 20%
is done the parasternal nodes and 5% is done by the posterior intercostal nerves
Lymph from the inferior breast quadrants may pass deeply to abdominal lymph
nodes
The skin also receives lymphatic drainage:
- Skin = drains to axillary, inferior deep cervical and infraclavicular nodes
- Nipple and areola = drains to the subareolar lymphatic plexus
THE AXILLA
Arterial The posterior intercostal artery runs between the internal and innermost intercostal
supply muscles and supplies the intercostal muscles, overlying skin and parietal pleura.
The anterior intercostal artery also supplies the same as above^
The internal thoracic artery passes between the costal cartilages and internal
intercostal muscles to divide into superior epigastric and musculophrenic arteries.
- The anterior intercostal arteries supply the intercostal spaces 1-6
- The musculophrenic arteries to intercostal spaces 7-9
Subcostal artery runs below the inferior border of 12th rib, it distributes to the
muscles of the anterolateral abdominal wall and overlying skin
Venous Anterior venous drainage is done by the anterior intercostal drains which drain
supply straight into the internal thoracic vein which branches off the subclavian vein,
deoxygenated blood finally returns to the heart
Posterior venous drainage is done by the posterior intercostal veins which drain into
the azygous vein on the right hand side = this vein connects the SVC to the IVC.
- At the arch of the azygous vein, it joins with the superior vena cava which
drains straight into the RA of the heart
- On the left side you have the hemi azygous and accessory azygous veins
which drain into the azygous veins
- The hemi azygous veins form as a combination of the last 9-12 posterior
intercostal veins
- Accessory azygous veins forms due to the union of posterior intercostal veins
at 4-8
- At T7/T8 the accessory azygous vein rains into the azygos vein and at T8/T9
the hemi azygous vein drains into the azygous vein
- This is them taken to the superior vena cava where the azygous vein drains
into
Nerve Typical intercostal nerves (3th-6th) – run across the internal surface of the internal
supply intercostal membrane and the muscle in the middle of the intercostal spaces
- When the nerves approach the angle of the ribs, they pass between the
internal intercostal and innermost intercostal muscles before continuing
inside of the costal grooves
- The intercostal nerves lie inferior to the intercostal arteries which are in turn
, are inferior to the intercostal veins
Atypical intercostal nerves (are the 1st, 2nd, 7th-11th)- intercostal nerves 1 and 2 pass
on the internal surfaces of the 1st and 2nd ribs instead of along the inferior margins of
the costal grooves
After giving rise to the lateral cutaneous branches, the 7th- 11th intercostal nerves
continue to supply the abdominal skin and muscles
Phrenic nerve = motor and sensory nerve of the diaphragm
Vagus nerve = provides parasympathetic supply for all the organs of the thorax and
abdomen
Intercostal nerves = direct continuation of the anterior rami of the thoracic spinal
nerves, this gives motor innervation to the intercostal muscles and sensory
innervation to the chest wall
Sympathetic trunk = runs alongside vertebral column to T1 down to the sacrum,
connections between sympathetic trunk and anterior rami of the spinal nerves =
rami communicantes
Lymphatic NONE NEEDED TO KNOW HERE
supply
THE BREAST
Arterial Medial mammary branches originating from the internal thoracic artery which in
supply turn originates from the subclavian artery – supplies the medial aspect of the breast.
Lateral aspect of the breast –
- Lateral mammary branches originating from the lateral thoracic artery which
originates from the axillary artery, originate from the posterior intercostal
arteries – derived from the aorta
(supply the lateral aspect of the breast in the 2nd 3rd and 4th intercostal spaces
, - Posterior intercostal artery branches – lateral cutaneous branch
- Mammary branch = originates from the anterior intercostal artery
- Pectoral branch from the thoracoacromial artery
Venous The venous drainage of the breast is mainly to the axillary vein, but there is some
supply drainage to the internal thoracic vein
- Drainage through the lateral mammary veins which drain into the lateral
thoracic vein and then the axillary vein
- Drainage through the medial mammary veins into the internal thoracic vein
Nerve Nerves of the breast derive from the anterior and lateral cutaneous branches of the
supply 4th to 6th intercostal nerves
These branches of the intercostal nerves pass through deep pectoral fascia covering
the pectoralis major to reach the skin, branches convey sensory fibres to the skin of
the breast and sympathetic fibres to the smooth muscle of the blood vessels in the
breast and overlying skin and nipple
Lymphatic Lymphatic drainage of the breast is important in its role of Metastasis of cancer, the
supply first stop if the subareolar lymphatic plexus, this is where the lymph first drains from
Lymph from the lateral quadrants:
- Axillary lymph nodes to the pectoral lymph node to the infra, supraclavicular
node to the subclavian lymphatic trunk
Lymph from medial quadrants:
- From parasternal lymph nodes to the broncho mediastinal trunks to the
thoracic duct, right lymphatic duct
75% of the lymphatic drainage of the breast is done to the axillary lymph nodes, 20%
is done the parasternal nodes and 5% is done by the posterior intercostal nerves
Lymph from the inferior breast quadrants may pass deeply to abdominal lymph
nodes
The skin also receives lymphatic drainage:
- Skin = drains to axillary, inferior deep cervical and infraclavicular nodes
- Nipple and areola = drains to the subareolar lymphatic plexus
THE AXILLA
