Neurovasculature Flashcards
The muscles of the thoracic wall
- Intercostal muscles
- transverses thorasis
- Subcostals
- serratus posterior superior
- serratus posterior inferior
External intercostal muscles:
- Muscle fiber direction
- superior and inferior attachment
- Action
- inferomedial (hands in pockets)
- Superior: Inferior margin of rib above
Inferior: superior margin of rib below - Elevate ribs during passive inspiration
How does the external intercostal muscle attach to the sternum (and at what region does the change occur)
Attaches to the sternum via the External Intercostal membrane which arises at the costochondral joint. If the external intercostal membrane is reflected, the internal intercostals will be seen
Internal intercostal muscles:
- fibre direction in relation to external intercostal muscles
- superior and inferior attachment
- action of muscle
- perpendicular to external intercostal muscles (superolateral direction- wakanda forever)
- superior: Inferior boarder of rib below
Inferior: superior boarder of rib above - depress rib cage in forced expiration
What structure/s can be used to differentiate/see the internal intercostal muscle from the innermost intercostal muscle
Neurovascular bundle
Running in all intercostal spaces as VAN (vein, artery, nerve)
What separates the parietal pleura from the intercostal muscles
Endothoracic fascia
Intercostal veins:
- how many posterior?
- how many anterior?
- how many subcostal?
- 11 pairs posterior
- 9 pairs anterior
- 1 pair subcostal
Where do the 1st intercostal veins drain into?
Left and right brachiocephalic veins
Where do the Left superior intercostal veins drain into?
Left brachiocephalic vein
Which intercostal veins form the left and right superior intercostal veins
Left superior ICVs:
left ICV 2,3,4
Right superior ICVs:
Right ICV 2,3,4
Where do the right superior ICVs drain to?
Azygos vein
What are the 2 veins received by the Left brachiocephalic vein?
- Internal jugular vein
2. Left Subclavian vein
Where does the azygos vein drain into and at what level does it enter this structure?
Superior vena cava
Level of T4
At what level does the azygos vein begin?
Level of L1/L2 at the region between the right subcostal vein and the right ascending lumbar vein
What vein is important for connection the inferior vena cava and superior vena cava to ensure that if the Inferior VC was obstructed, there would be alternate routes of drainage
Azygos vein
What are the 2 main tributaries of the azygos vein, which veins do they drain and how do they reach the azygos vein?
Hemiazygos:
- Left ICVs 9-10
- cross over at T8/ T9
Accessory hemiazygos vein
- Left ICVs 5-8
- cross over at T7/ T8
Which are the 3 main arteries from which the Intercostal arteries arise?
- Thoracic aorta
- Subclavian artery
(Those are the major ones) - Axillary artery
Which 2 intercostal arteries are branches of the Thoracic aorta?
- Posterior intercostal arteries (3-11)
2. Subcostal artery (12)
Which intercostal artery is a branche of the SUPERIOR INTERCOSTAL ARTERY that arise from the Costocervical trunk of the Subclavian artery?
- Posterior intercostal artery (1+2)
What is the other artery that is a branch of the subclavian artery?
Internal thoracic artery
What are the 5 branches of the Internal thoracic artery?
Mom Swallowed Ancient Pineapple Sauce
- Musculophrenic artery
- Superior Epigastric artery
- Anterior Intercostal arteries (AICAs 1-6)
- Perforating branches
- Sternal artery
Describe the branches of the Anterior Intercostal Arteries
Upper 6:
- Branches of Internal thoracic artery which is a branch of the subclavian artery
AICAs 7-9:
- Branches of Musculophrenic artery which is a branch of the Internal Thoracic artery
In relation to the Anterior Intercostal Arteries, which 2 arteries branch from the Internal thoracic artery and at what level does this bifurcation/branching take place?
- Musculophrenic artery
- branches of AICAs 7-9 - Superior Epigastric artery
- supply the rectus abdominus muscles and proceed inferiority to anastomose with the inferior Epigastric artery
The bifurcation takes place at the 6th intercostal space
Where do the Posterior Intercostal arteries anastomose with the 2 Anterior intercostal arteries that supply the intercostal spaces (anteriorly)
Anteriorly at the Costchondral junction
Where are the 1st and 2nd Anterior Intercostal Arteries found?
Endothoracic Fascia
Do the 10th and 11th intercostal spaces have anterior intercostal arteries?
No, they only have posterior intercostal arteries
