Superficial Structures of the Neck 1 Flashcards
Where does the first pair of cervical nerves leave the spinal cord and the vertebral column?
Above the 1st cervical vertebrae, between the first cervical vertebrae and the base of the skull.
How do the 7 remaining cervical vertebrae leave the cervical vertebrae?
Through their corresponding intervertebral foramina.
What happens to the spinal nerve after leaving the intervertebral foramina?
Immediately after, they divide into dorsal and ventral ramus.
What do the dorsal rami of the spinal nerves supply?
They supply the extensor muscles at the back of the neck and the skin overlying them.
In the cervical region, what happens to the upper 4 cervical ventral rami?
They branch and mix with each other before they pass onwards to skin and muscles.
What is the path of the lower 4 cervical ventral rami?
They stream towards the upper limb.
What do the lower 4 cervical ventral rami join with?
They join with the 1st thoracic ventral ramus and they form a plexus that supplies the arm.
What is the cervical plexus formed off?
It is formed off the upper 4 ventral rami.
What is the brachial plexus formed off?
It is formed of the lower 4 rami together with the 1st thoracic ramus.
What do each of the transverse processes of the cervical vertebrae have?
They have a foramen in them for the vertebral arteries.
What do each of the transverse processes end in?
They end in 2 tubercules – an anterior and a posterior tubercule.
How do the cervical ventral rami pass out over the transverse processes?
They pass out in a shallow gutter between the anterior and posterior tubercules.
Where do the scalene muscles originate from?
They originate from the 2 tubercules of the transverse processes of the cervical vertebrae.
Where do the scalene muscle run to?
They run from the cervical vertebral column to the 1st and 2nd ribs.
Where do the scalene muscles lie?
They lie at the sides of the vertebral column.
Where do the scalenus anterior muscles attach to?
They attach to the anterior tubercules.
Where does the scalenus medius attach to?
They attach to the posterior tubercules.
Other than the scalenus medius, what other muscles attach to the posterior tubercules?
- scalenus posterior
- levator scapulae
How do the ventral rami of the cervical spinal nerves emerge into the neck?
They emerge between the scalenus anterior and the scalenus medius.
What do the upper 4 ventral rami give branches to supply?
Their branches supply many muscles in the neck and also the skin of the sides and the front of the neck.
What do a few muscular branches from the 1st cervical ventral ramus hitch hike along?
They enter the hypoglossal nerve and hitch hike along it.
How do the muscular fibres from the first cervical ventral ramus leave the hypoglossal nerve?
They leave the nerve in the front of the neck as the superior root of the ansa cervicalis and as the thyrohyoid nerve.
What do muscular branches from the 2nd and 3rd ventral rami form?
They form the inferior root of the ansa cervicalis.
Where do fine branches from the loop of the ansa go to?
They pass to the muscles at the front of the neck.
What does a muscular branch from the 4th ventral ramus supply?
It supplies muscles that originally developed in the neck but which later migrated to the thorax = diaphragm
What is the muscular branch of the 4th cervical ventral ramus called?
This is called the PHRENIC NERVE
Where does the phrenic nerve recieve some filaments from on its way to the surface of the scalenus anterior muscle?
It recieves filaments from the 3rd and 5th ventral rami which pass onto the surface of the scalenus anterior muscle.
What is the path of the scalenus anterior muscle?
- crosses the scalenus anterior muscle obliquely
- passes in front of the subclavian artery
- passes through the superior aperture of the thorax
Why is the broken neck above the level of C4 fatal?
Because the diaphragm is completely paralysed.
Where do the cutaneous branches from the cervical plexus emerge?
They emerge at the side of the neck and then radiate into the skin like the spokes of a wheel.
What are the cutaneous branches of the cervical plexus called?
- lesser occipital
- great auricular
- transverse cervical
- supraclavicular nerves
Where do the 5th, 6th, 7th and 8th ventral emerge?
They emerge low in the neck between the scalenus anterior and scalenus medius.
How are 3 trunks formed from the brachial plexus?
- 5th and 6th ventral rami join together –> upper trunk
- 7th ventral rami stays single –> middle trunk
- 8th cervical ventral rami + 1st thoracic ramus –> lower trunk
How do the 3 trunks enter the upper limb?
They stream over the first rib with the subclavian artery and into the upper limb.
What covers the prevertebral and scalene muscles?
A sheet of prevertebral fascia.
When they first emerge from the intervertebral foramina, where does the cervical ventral rami lie in relation to the prevertebral fascia?
They first lie deep to this fascia.
What do the cervical ventral rami have to do in order to make sure that they can reach the structures that they supply?
They have the pierce the prevertebral fascia.
What part of the prevertebral fascia do the brachial plexus and subclavian artery pierce?
They pierce a triangular area that lies between the scalenus anterior and the scalenus medius.
What is the axillary sheath?
The subclavian artery carries with it a sheat of the prevertebral fascia into the upper limb and here it is called the axillary sheath.
Does the subclavian vein pierce the prevertebral fascia?
No - it passes over the first rib in front of the scalenus anterior and therefore it does not pierce the prevertebral fascia.
Where does the cervical part of the sympathetic extend from, to?
It extends from the base of the skull to the superior aperture of the thorax.
Where is the cervical part of the sympathetic trunk continuous with the thoracic part of the sympathetic trunk?
It is continuous through the superior aperture of thorax.
Describe the preganglionic neurones in the trunk.
They have all ascended from the thoracic region. There is no preganglionic outflow from the cervical part of the spinal cord.
Where do sympathetic neurones from the thoracic region ascend to?
The ascend to 1 of 3 cervical sympathetic ganglia on the trunk.
What are the 3 cervical sympathetic ganglia on the trunk called?
They are called the superior, middle and inferior cervical sympathetic ganglia.
What is the inferior cervical sympathetic ganglion fused with?
It is fused with the first thoracic ganglion to form a large cervicothoracic ganglion.
What is the cervicothoracic ganglion sometimes called?
It is sometimes called the stellate ganglion because it has a flattened star like appearance.
Where does the stellate ganglion lie?
It lies on the neck of the first rib.
Where do postganglionic sympathetic fibres arise from?
They arise from all 3 cervical sympathetic ganglia.
How do postganglionic sympathetic ganglia reach their targets in the head and neck?
Many of them climb along blood vessels to reach their destination in the head and the neck.
