Deep structures of the neck

Question 1

Describe the boundaries of the root of the neck- anterior, lateral, posterior and inferior

Answer 1

Anterior- top of the manubrium and superior border of clavicle
Lateral- first pair of ribs and associated costal cartilage
Posterior- superior margin of scapula and body of T1
Inferior- openings into thorax and axilla, superior thoracic aperture and axillary inlets on each side

Question 2

where is the superior thoracic aperture located?

Answer 2

In the anterior triangle, superior border of the manubrium

Question 3

Where are the axillary inlets located?

Answer 3

in the posterior triangles

Question 4

At what level does the axillary vein become the subclavian vein?

Answer 4

The axillary vein draining the upper limbs becomes the subclavian vein at the border of the 1st ribs.

Question 5

At what level does the subclavian artery become the axillary artery?

Answer 5

The subclavian artery branches off the arch of aorta and becomes the axillary artery at the level of the lateral border of 1st ribs.

Question 6

Which major nerve structures pass through the axillary inlet?

Answer 6

The brachial plexus passes through the axillary inlet on each side

Question 7

What is the brachial plexus?

Answer 7

The brachial plexus is a major plexus of nerves formed of the anterior rami of 5 spinal nerves - C5-8 and T1
this forms 3 trunks and then 5 terminal branches which innervate the upper limbs

Question 8

The brachial plexus emerges between which muscles in the neck?

Answer 8

The brachial plexus emerges between the anterior and middle scalene muscles

Question 9

What level does the apex of the lungs extend to?

Answer 9

The apex of the lungs extends beyond the 1st ribs, posterior to the inferior attachment of SCM

Question 10

There is 2 types of pleura which covers the lungs, name these and their differences?

Answer 10

The visceral pleura- closely covers the surface of the lungs
The cervical pleura- superior continuation of parietal pleura which is more substantial than visceral pleura.

Question 11

Cervical pleura is reinforced by a fibrous extension of endothoracic fascia, where does this attach and what s its function?

Answer 11

The endothoracic fascia attaches to the internal border of 1st rib and transverse process of vertibrae prominens C7
Its function is to act as a barrier to prevent changes in intrathoracic pressure drawing upon contents of the neck

Question 12

What is the suprapleural membrane

Answer 12

The fibrous extension of the endothoracic fasica is also referred to as the suprapleural membrane- this is a barrier to changes in intrathoracic pressure

Question 13

which areas does the subclavian artery supply?

Answer 13

the subclavian artery supplies the supper limbs, neck and brain

Question 14

Describe the course of the subclavian vein.

Answer 14

ascends through superior thoracic aperture to enter the root of the neck
divided into 3 parts (in relation to position of anterior scalene muscle)- 1st division (medial, pre-scalene), 2nd division (posterior, retro-scalene), 3rd division (lateral, post-scalene)
The artery then continues, passing over the lateral margin of 1st rib, where is becomes the axillary artery.

Question 15

Name the 5 main branches of the subclavian artery in the neck.

Answer 15

vertebral artery (1st)
internal thoracic artery (1st)
thyrocervical trunk (1st)

Costocervical trunk (2nd)

Dorsal scapular artery (3rd)

Question 16

Describe the course of the vertebral artery and what structures it supplies.

Answer 16

The vertebral artery is a branch of the pre-scalene subclavian artery.

the cervical portion ascends between scalene and longus capitus and colli muscles where it passes through foramen transversarium of C6 to C1.

the suboccipital portion runs in a groove in posterior arch of atlas (C1) and enters the cranial cavity via foramen magnum.

this becomes the cranial portion which supplies structures of the brain, spinal cord and posterior cranial fossa.

the vertebral arteries join at inferior border of pons to form basilar artery - circle of Willis

Question 17

Easy way to remember the branches of the subclavian artery

Answer 17

VIT C and D

Question 18

Briefly describe the course of the thyrocervical trunk

Answer 18

This arises from re-scalene subclavian artery and gives rise to 3 branches-
inferior thyroid artery (supplies larynx, pharynx, trachea and oesophagus, thyroid and parathyroid glands and associated muscles)
transverse cervical (trapezius muscle)
suprascapular artery

Question 19

Which branches of the subclavian run anterior to the anterior scalene muscle?

Answer 19

2 branches of the thyrocervical trunk- transverse cervical and suprascapular artery

Question 20

Describe briefly, the course of the costocervical trunk

Answer 20

The costocervical trunk arises from the retro-scalene portion of the subclavian artery, travels superiorly and divides into supreme intercostal and deep cervical

Question 21

Briefly describe the course of the dorsal scapular artery

Answer 21

The dorsal scapular artery arises from the post-scalene portion of the subclavian artery- this is heavily variable and is sometimes even a branch of the thyrocervical trunk

Question 22

Describe the course of the subclavian vein

Answer 22

The subclavian vein is a continuation of the axillary vein (passes over 1st rib parallel to subclavian artery, separated by scalene), joins the IJV and becomes the brachiocephalic vein at the venous angle.

Question 23

What is the main role of prevertebral muscles?

Answer 23

the main role of prevertebral muscles is to flex and rotate the head

Question 24

Describe the course and the drainage of the external jugular vein

Answer 24

The external jugular vein runs superior to and across SCM from the angle of mandible to mid clavicle, draining into the subclavian vein

Question 25

Which other blood vessels drain into the EJV?

Answer 25

The posterior external jugular, transverse cervical, suprascapular, anterior jugular

Question 26

name the 4 anterior vertebral muscles

Answer 26

Longus colli
longus capiti anterior
rectus capitis anterior
anterior scalene

Question 27

name the 4 lateral vertebral muscles

Answer 27

rectus capitis lateralis
splenius capitis
levator scapulae
middle and posterior scalenes