part 4 Flashcards
What are the different parts of the subclavian artery
Part 1- different left compared to right
a.right comes off the brachiocephalic trunk behind the SC joint > ascends superior and lateral to anterior scalene
b.left comes aortic arch behind the common carotid > passes superior border of the anterior scalene
Part 2- passes posterio to the anterior scalene
Part 3- passes up and over 1st rib into the supraclavicular triangle > turns into axillary artery
What structure separates the subclavian artery and vein?
anterior scalene
What are the four anatomical spaces relevant to the thoracic outlet?
- sternocostovertebral
- scalene triangle
- costocalvicular space
- pectoralis minor space
What are the borders of the sternocostovertebral space?
- Sternum anteriorly
- spine posteriorly
- first rib laterally
What is found in the sternocostovertebral space?
- subclavian vein
- subclavian artery
- brachial plexus
- apex of the lung
- pleura
- sympathethetic trunk
- jugular vein
- lymphatics of the neck
What are the borders of the scalene triangle?
Anterior scalene
middle scalene
first rib
What are the borders of the costoclavicular space?
- one third of the clavicle and subclavius anteriorly
- first rib and sclene insertion medially
- superior border of the scapula posteriorly
What is found in the costoclavicular space?
- costoclavicular ligament
- subclavian vien
- subclavian artery
- brachial plexus
What are the borders of the pectoralis minor space and what is found in the space?
- ribs
- pectoralis minor
- brachial plexus and axillary vessels
Are cervical rib a pathological condition?
No, only 1.2% of patient with upper extremity symptomology are found to have cervical ribs
How many types of congenital fibromuscular band are been identified in the thoracic outlet?
1- anterior tip of incomplete cervical rib to posterior scalene tubercle
2- tip of enlarger C8 TP to posterior scalane tubercle
3- muscular band from body of T1 TP across the space to the first rib
4- connection between anterior and middle scalene
5- scalenes minimus from TP of lower cervical spine to attachbtween Middle and anterior scalene
6- scalene minimus that attaches to the pleura
7- passess beneth the subclavian vein
What are some examples of congenital anomolies that influence the thoracic outlet?
- fibrous bands
- hypoplastic first rib
- exostosis of the first rib or clavicle
Describe the myofacial layer that cover the region of the thoracic outlet
- Deep cervical fascial wraps arond the posterior belly of the omohyoid
- it travels down and splits to envelope the subclavius
- it then joints the clavicopecotoral fascia with a thickening of the costocoracoid membrane
- splits again to enclose pectoralis minor
- it terminates at suspensory ligament of the axilla
What is the true tissue in lesion the anterior scalene TOS
1.C3 innervates anterior scalene
increases tone in anterior scalene and effect TOS
2.C3 innervates diaphragm
3.dysfunction of the diaphragm leads to upper respiratory breathing
What is costocalvicular syndrome?
the vascular structures are compressed by clavicle on the first rib with retracted and depressed scapula
Why is there some controversy over costoclavicular syndrome?
some studies have demonstrated that as the clavicle is depressed it actually moves forward and increases the space between the first rib and clavicle
How can you test for costoclavicular syndrome?
- exagerated military posture
- deep inspiration
- monitor pulse
What is hyper abduction syndrome?
- At 180 degree of elevation the neurvscular bundle is bent at a 90 degree angle around the coracoid process
- contraction of the pec minor or subscapularis will compress the neurovascular bundle