Root of the neck - scalenus anterior (dave's notes) Flashcards
What is the origin and attachment of scalenus anterior?
Arises from C3-6 with 4 slender tendons lying end to end with those of longus capitus, ending in a narrow tendon attached to the scalene tubercle and ridge of the inner border of the upper surface of the first rib.
What covers scalenus anterior?
A prolongation of the prevertebral fascia
What is the nerve supply to scalenus anterior?
Segmental
List the anterior relations of scalenus anterior
Phrenic nerve Ascending cervical artery Transverse cervical and suprascapular arteries Vagus nerve Internal jugular vein Subclavian vein
List the medial relations of scalenus anterior
Edge of longus colli Subclavian artery 1st rib Thoracic duct/Right lymphatic duct Carotid tubercle Common carotid artery Stellate ganglion Vertebral artery and veins Inferior thyroid artery Ansa cervicalis Connecting loop between middle and inferior cervical ganglia Vertebral vein
List the posterior relations of scalenus anterior
Subclavian artery
Anterior rami of C7/T1
Scalenus medius
List the lateral relations of scalenus anterior
Trunks of the brachial plexus
The 3rd part of the subclavian artery
Why do the arteries have free entry to the pyramidal space?
There is no prevertebral fascia here
Anterior relation of scalenus anterior: describe the course of the phrenic nerve
Passes vertically downwards plastered by the prevertebral fascia, then crosses the subclavian artery. From the supra pleural membrane it passes medially to the apex of the lung anterior to the vagus
Anterior relation of scalenus anterior: Describe the course of the ascending cervical artery
From inferior thyroid artery/thyrocervical trunk it runs up medial to the phrenic nerve on the prevertebral fascia
Anterior relation of scalenus anterior: what two arteries are found between scalenus anterior and the carotid sheath?
Transverse cervical and suprascapular arteries
Anterior relation of scalenus anterior: Describe the course of the vagus nerve
The vagus nerve in the carotid sheath passes down in front of the subclavian artery (giving off the recurrent on the right). The vagus inclines posteriorly running on the medial surface of the apex of the lung
What surrounds the internal jugular vein?
The inferior deep cervical lymph nodes
Anterior relation of scalenus anterior: Where is the subclavian found relative to scalenus anterior?
The subclavian vein lies in a groove on the first rib, lying lower than the insertion of the scalenus anterior
Medial relation of scalenus anterior: What makes a pyramidal space with scalenus anterior?
The medial edge of longus colli running up on the anterior tubercle of C6
Medial relation of scalenus anterior: What is found at the base of the pyramidal space?
The subclavian artery and neck of the first rib, the thoracic duct (lymph duct on the right) arches over the lung apex and subclavian artery to enter at the confluence
What are the branches of the subclavian artery?
Vertebral
Thyrocervical trunk
Internal thoracic artery
What are the branches of the thyrocervical trunk?
Transverse cervical
Suprascapular
Inferior thyroid artery
Medial relation of scalenus anterior: What is at the apex of the pyramidal space?
The carotid tubercle
Medial relation of scalenus anterior: What lies immediately in front of the pyramidal space?
The common carotid artery
Medial relation of scalenus anterior: What arches in front of the apex of the pyramidal space?
The internal thoracic artery.
Describe the course of the vertebral vein from C6
The vertebral vein emerges from the foramen in the transverse process of C6, runs over the apex of the lung and beneath the subclavian artery to the brachiocephalic vein
Posterior relations of scalenus anterior: Describe the second part of the subclavian artery
The second part of the subclavian artery is the part lying behind scalenus anterior. It gives rise to the costorcervical trunk (which gives of the superior intercostal artery and deep cervical artery)
Posterior relations of scalenus anterior: What separates scalenus anterior from scalenus medius?
The subclavian artery and the anterior rami of C7/T1
Lateral relations of scalenus anterior: What plasters down the trunks of the brachial plexus?
The prevertebral fascia
Posterior relations of scalenus anterior: Describe the third part of the subclavian artery
The third part of the subclavian artery is behind the prevertebral fascia and gives off the dorsal scapular branch
