Intercostal Vessels Flashcards
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What are intercostal nerves?
The ventral rami of thoracic spinal nerves T1-T11, which run in the intercostal spaces.
How many intercostal nerves are there?
11 pairs (T1-T11), corresponding to the 11 intercostal spaces.
What is the course of the intercostal nerves?
They run between the internal intercostal and innermost intercostal muscles, in the costal groove of the rib.
What is the relationship of the intercostal nerve to the intercostal artery and vein?
The nerve runs inferior to the artery and vein in the costal groove (mnemonic: VAN = Vein, Artery, Nerve from top to bottom).
What are the branches of a typical intercostal nerve?
- Muscular branches (to intercostal muscles), 2. Collateral branch (to lower intercostal space), 3. Lateral cutaneous branch (to skin), 4. Anterior cutaneous branch (to skin).
What is the function of the muscular branches of the intercostal nerves?
They supply the intercostal muscles (external, internal, and innermost intercostals) and the transversus thoracis muscle.
What is the function of the lateral cutaneous branch of the intercostal nerves?
It pierces the intercostal muscles near the mid-axillary line to supply the skin of the lateral thoracic and abdominal walls.
What is the function of the anterior cutaneous branch of the intercostal nerves?
It pierces the intercostal muscles near the sternum to supply the skin of the anterior thoracic and abdominal walls.
What is the collateral branch of the intercostal nerve?
A small branch that supplies the intercostal muscles and parietal pleura in the lower part of the intercostal space.
What is the sensory distribution of the intercostal nerves?
They supply the skin over the thorax and abdomen (T7-T11 also supply the anterior abdominal wall).
What is the clinical significance of the T10 dermatome?
It supplies the skin around the umbilicus, making it important in diagnosing referred pain (e.g., appendicitis).
What is the clinical significance of the intercostal nerves in herpes zoster?
Herpes zoster (shingles) can affect intercostal nerves, causing a painful, vesicular rash along the dermatome of the affected nerve.
What is the clinical significance of the intercostal nerves in thoracotomy?
Damage to intercostal nerves during thoracotomy can lead to post-thoracotomy pain syndrome, characterized by chronic pain along the incision site.
What is the clinical significance of the intercostal nerves in rib fractures?
Rib fractures can damage intercostal nerves, causing sharp, localized pain and sometimes referred pain along the dermatome.
What is the clinical significance of the intercostal nerves in abdominal surgery?
T7-T11 intercostal nerves supply the anterior abdominal wall, so damage can lead to weakness or sensory loss.
What is the clinical significance of the intercostal nerves in pregnancy?
Stretching of the abdominal wall can cause irritation of the intercostal nerves, leading to pain.
What is the clinical significance of the intercostal nerves in referred pain?
Pain from visceral organs (e.g., heart, gallbladder) can be referred to the corresponding dermatome (e.g., T1-T4 for cardiac pain).
What is the clinical significance of the intercostal nerves in intercostal nerve block?
Used to provide analgesia for rib fractures or post-thoracotomy pain by injecting local anesthetic near the intercostal nerve.
What is the clinical significance of the intercostal nerves in diaphragmatic irritation?
Irritation of the diaphragm (e.g., by blood or infection) can cause referred pain to the shoulder (C3-C5) or lower intercostal spaces (T7-T12).
What is the clinical significance of the intercostal nerves in chest trauma?
Damage to intercostal nerves can cause sensory loss or pain in the corresponding dermatome.
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What are the intercostal arteries?
Arteries that supply the intercostal spaces, divided into posterior and anterior intercostal arteries.
How many posterior intercostal arteries are there?
11 pairs (one for each intercostal space).
What is the origin of the posterior intercostal arteries?
- The first two posterior intercostal arteries arise from the supreme intercostal artery (a branch of the costocervical trunk). 2. The lower nine arise directly from the thoracic aorta.
What is the origin of the anterior intercostal arteries?
They arise from the internal thoracic artery (a branch of the subclavian artery) and its terminal branch, the musculophrenic artery.
What is the course of the posterior intercostal arteries?
They run in the costal groove of the rib, between the internal intercostal and innermost intercostal muscles.
What is the course of the anterior intercostal arteries?
They run along the lower border of the rib, anastomosing with the posterior intercostal arteries.
What is the relationship of the intercostal artery to the intercostal vein and nerve?
The artery runs between the vein (superior) and the nerve (inferior) in the costal groove (mnemonic: VAN = Vein, Artery, Nerve from top to bottom).
What is the collateral circulation in the intercostal spaces?
Collateral branches of the posterior and anterior intercostal arteries anastomose in the intercostal space, ensuring blood supply even if one artery is blocked.
What is the clinical significance of the internal thoracic artery?
It is commonly used as a graft in coronary artery bypass surgery (CABG).
What is the clinical significance of the supreme intercostal artery?
It supplies the first two intercostal spaces and is a branch of the costocervical trunk (from the subclavian artery).
What is the clinical significance of the musculophrenic artery?
It is a terminal branch of the internal thoracic artery and supplies the lower intercostal spaces and diaphragm.
What is the clinical significance of intercostal artery damage?
Damage can lead to hemothorax (blood in the pleural cavity) or ischemia of the intercostal muscles.
What is the clinical significance of the intercostal arteries in aortic coarctation?
Collateral circulation through the intercostal arteries can lead to rib notching on X-ray.
What is the clinical significance of the intercostal arteries in chest trauma?
They can be injured in rib fractures or penetrating trauma, leading to significant bleeding.
What is the clinical significance of the intercostal arteries in thoracotomy?
Care must be taken to avoid damaging the intercostal arteries during surgical procedures.
What is the venous drainage of the intercostal spaces?
- Posterior intercostal veins drain into the azygos/hemiazygos system. 2. Anterior intercostal veins drain into the internal thoracic vein.
What is the clinical significance of the azygos system?
It provides an alternative venous drainage pathway if the SVC is obstructed.
What is the clinical significance of the intercostal arteries in lung cancer?
Tumors can compress or invade the intercostal arteries, leading to ischemia or bleeding.
What is the clinical significance of the intercostal arteries in thoracic outlet syndrome?
Compression of the subclavian artery can affect blood flow to the intercostal arteries.
What is the clinical significance of the intercostal arteries in congenital heart disease?
Collateral circulation through the intercostal arteries may develop in conditions like tetralogy of Fallot.
