Here is a term paper on the ‘Pre-Vertebral Region and Root of the Neck’. Find paragraphs, long and short term papers on the ‘Pre-Vertebral Region and Root of the Neck’ especially written for school and college students.
Term Paper # 1. Bony Framework of Pre-Vertebral Region of the Neck:
It is formed of seven cervical vertebrae.
Superior surface of manubrium sterni.
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1st rib – slopes downwards and forwards.
Articulated cervical vertebrae when clothed with muscles attached to anterior tubercles of transverse processes, present a relatively flat prevertebral surface.
Deep cervical muscles are classified as:
A. According to their Position:
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I. Pre-Vertebral Muscles:
Present in front of vertebral bodies, e.g., Longus colli, Longus capitis, Rectus capitis anterior and Rectus capitis lateralis.
II. Para-Vertebral Muscles:
Connect the cervical vertebral column with the thoracic cage, e.g., Scalenus anterior, Scalenus medius, Scalenus posterior, Scalenus minimus and Levator scapulae.
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B. Classification According to Relation of Muscles with Cervical and Brachial Plexus:
I. Muscles Medial to Plexus – Longus colli, Longus capitis, Rectus capitis anterior and Scalenus anterior.
II. Muscles Lateral to Plexus – Rectus capitis lateralis, Scalenus medius, Scalenus posterior and Levator scapulae.
Structure Infront of Neck of 1st Rib:
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From medial to lateral side are:
1. Sympathetic trunk with T1 ganglion or stellate ganglion.
2. First posterior intercostal vein.
3. Superior intercostal artery.
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4. Ascending branch of ventral ramus of T1 to join with C8 ventral rami to from lower trunk of brachial plexus.
5. Apex of lung lies infront of all above structures.
Term Paper # 2. General Features of Pre-Vertebral Muscles of Neck:
1. Lie infront of vertebral column.
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2. Are covered anteriorly by a thick pre-vertebral fascia.
3. Form the posterior boundary of retropharyngeal space.
4. Extend from base of skull to the superior mediastinum.
5. Are weak flexors of the head and neck. Rectus capitis lateralis causes lateral flexion.
6. Supplied by ventral rami of C1 and C2 cervical nerves except longus colli which is supplied by C2 to C6 nerves.
Scaleno Vertebral Triangle:
This triangular space is present at the root of the neck on either side.
Boundaries:
Medial – Lower oblique part of longus colli.
Lateral – Scalenus anterior.
Apex – At transverse process of C6 vertebra.
Base – First part of subclavian artery.
Floor – Neck of 1st rib and cupola of the pleura.
Contents:
1. First part of vertebral artery and vertebral vein.
2. Cervical part of sympathetic trunk.
Paravertebral Muscles:
1. Scalenus anterior
2. Scalenus medius
3. Scalenus posterior.
General Features:
1. Scalenus medius is the largest and scalenus posterior is the smallest of the three scalene muscles.
2. Scalenus anterior is the ‘Key’ muscle of the paravertebral region.
3. Scalenus muscles extend from the transverse process of the cervical vertebrae to the first two ribs.
4. They can either elevate the ribs as in inspiration or bend the cervical part of the vertebral column laterally to ipsilateral side.
I. Muscles Medial to Plexus:
1. Longus colli has three parts:
(a) Upper Oblique Part:
Origin:
Anterior tubercle of transverse – process of C3, C4 and C5 vertebrae.
Insertion:
Anterior arch of atlas.
(b) Intermediate Vertical Part:
Origin:
Anterior surface of bodies of T1, T2 and T3 vertebra.
Insertion:
Anterior surface of bodies of C5, C6, C7 vertebra.
(c) Lower Oblique Part:
Origin:
Anterior surface of bodies of T1, T2, T3 vertebra.
Insertion:
Anterior tubercle of transverse process of C5, C6 vertebra.
Nerve Supply:
Ventral rami of C3, C4, C5 and C6 nerves.
Action:
Flexor of neck.
2. Longus Capitis:
Origin:
Anterior tubercle of transverse process of C3, C4, C5 and C6 vertebra (typical cervical vertebra).
Insertion:
Basilar part of occipital bone.
Nerve Supply:
Ventral rami of C2, C3, C4, C5 and C6 nerves.
Action:
Flexor of neck.
3. Rectus Capitis Anterior:
Origin:
Transverse process and lateral mass of atlas.
Insertion:
Basilar part of occipital bone.
Nerve Supply:
Ventral rami of C1, C2 nerves.
Action:
Flexor of neck.
4. Scalenus Anterior:
It is a flat and ribbon shaped ‘Key’ muscle of lower part of neck because of its relations to many important structures in this region, i.e., subclavian artery, vein and nerves (Phrenic and brachial plexus).
Origin:
Anterior tubercle of transverse process of C3, C4, C5 and C6 vertebra (typical cervical vertebra).
Insertion:
Scalene tubercle present on inner border of 1st rib.
Nerve Supply:
Ventral rami of C4, C5, C6 nerves.
Action:
1. It is an accessory respiratory muscle i.e., lifts the first rib up and increases the vertical diameter of chest.
2. Flex the neck forwards.
Important Features:
1. Divides the subclavian artery into three parts.
2. Phrenic nerve and pre-vertebral fascia are found anterior to muscle.
3. Behind the muscle – subclavian artery and brachial plexus are present.
Relations of Scalenus Aanterior:
Anterior:
Phrenic nerve
Subclavian vein
Pre-vertebral fascia
Transverse cervical artery
Supra scapular artery
Ascending cervical artery branch of inferior thyroid artery
Lateral part of carotid sheath containing internal jugular vein
Descendens cervicalis – C2 and C3 nerve fibres
Inferior belly of omohyoid
Anterior jugular vein
Sternomastoid branches of superior thyroid and supra scapular arteries
Sternomastoid and clavicle.
Posterior:
Brachial plexus – roots
IInd part of subclavian artery
Medial part of scalenus medius
Cervical pleura covered by suprapleural membrane.
Medial:
Carotid sheath, sympathetic chain, thyro cervical trunk and vertebral artery.
Lateral:
Trunks of brachial plexus
IIIrd part of subclavian artery
Scalenus medius and posterior muscles.
II. Muscles Lateral to Plexus:
1. Rectus Capitis Lateralis:
Origin:
Transverse process and lateral mass of atlas.
Insertion:
Basilar part of occipital bone infront of jugular process.
Nerve Supply:
Ventral rami of C1 nerve.
Action:
Stabilizes atlanto occipital joints.
2. Scalenus Medius:
Forms part of floor of posterior triangle of neck.
Origin:
Posterior tubercle of transverse process of C3, C4, C5 and C6 vertebra (typical cervical vertebra).
Insertion:
Superior surface of 1st rib behind subclavian artery and brachial plexus.
Nerve Supply:
Ventral rami of C4, C5, C6 nerves.
Action:
Elevation of 1st rib and
Forward flexion of cervical vertebral column.
Structures Piercing the Muscle:
1. Nerve to rhomboids (C5)
2. C5, C6 roots of long thoracic nerve.
Relations of Scalenus Medius:
Anterior:
Roots of brachial plexus
Second part of subclavian artery
Scalenus anterior muscle
Dorsal scapular nerve (C5) and
Upper two roots of nerve to serratus anterior C5 and C6 – pierce it.
Posterior:
Levator scapulae
Scalenus posterior.
3. Scalenus Posterior:
Origin:
Posterior tubercle of transverse process of C4, C5, C6 vertebra.
Insertion:
2nd rib.
Nerve Supply:
Ventral rami of C4, C5, C6 nerves.
Action:
Accessory respiratory muscle lifts 2nd rib upwards → ↑ vertical diameter of chest and forward flexion of cervical vertebral column.
4. Scalenus Minimus:
Arises from transverse process of C7.
Inserted:
On inner border of 1st rib and cervical pleura.
Applied:
Scalene anticus synodrome – cervical rib or spasm of scalene muscles or over-crowding of scalene muscles may compress the subclavian artery and brachial plexus. The nerve usually involved is C8 and T1 (Lower Trunk).
Fullness or swelling in posterior triangle.
Neurological Symptoms:
i. Tingling, numbness, anaesthesia
ii. Hyperasthesia, parasthesia
iii. Wasting of hypothenar muscles.
Ischemia of Upper Limb:
Cynosis of hand, necrosis of finger tips, digital gangrene etc.
Cervical Plexus:
It is a network of nerves formed in the upper part of neck by ventral rami of C1 to C4 nerves.
Except first cervical nerve, other nerves divide into ascending and descending branches. These nerves unite to form loops on the anterior surface of scalenus medius and levator scapulae muscles.
Plexus is covered by the prevertebral fascia.
Plexus is superficially related to:
1. Sternocleidomastoid muscle
2. Internal jugular vein.
Branches:
These are superficial, deep and communicating branches.
I. Superficial Branches:
They are cutaneous, e.g.,
1. Transverse cutaneous nerve of neck – C2, C3.
2. Lesser occipital nerve – C2.
3. Great auricular nerve – C2, C3.
4. Supra clavicular nerves – C3, C4.
II. Deep Branches:
A. Muscular:
1. Phrenic nerve – C3, C4, C5 – supplies diaphragm.
2. Rectus capitis lateralis – C1.
3. Rectus capitis anterior – C1.
4. Longus capitis – C1 to C4.
5. Longus colli – C3 to C8.
6. Inferior limb of ansa cervicalis – C2, C3.
7. Scalenus anterior – C4, C5, C6.
B. Posterior Branches:
Posterior branches to supply:
1. Sternocleido mastoid – C2, C3.
2. Levator scapulae – C3, C4, C5.
3. Trapezius – C3, C4.
4. Scalenus medius – C3, C4.
III. Communicating Branches:
(a) Superior cervical sympathetic ganglion communicates with C1 to C4 nerves by grey rami communicants.
(b) A branch from C1 joins hypoglossal nerve and forms superior limb of ansa cervicalis.
Superior and inferior limb of ansa cervicalis joins and supplies infra hyoid muscles.
Some fibres of C1 continue into hypoglossal nerve and supply thyrohyoid and geniohyoid.
Applied Anatomy:
1. In case of meningitis – neck rigidity may occur due to involvement of cervical nerves.
2. Cervico occipital neuralgia.
Brachial Plexus:
It lies in the lower part of neck on the surface of scalenus medius deep to scalenus anterior and pre- vertebral fascia.
It is formed by ventral rami of lower four cervical nerves and T1 with variable contribution from C4 and T2.
Parts of Brachial Plexus:
1. Roots:
C5, C6, C7, C8 and T1 ventral rami.
2. Trunks:
C5 and C6 roots join and form upper trunk.
C7 forms middle trunk.
C8 and T1 roots join and form lower trunk.
3. Divisions:
Each trunk splits into an anterior and a posterior division behind the clavicle.
4. Cords:
All three posterior divisions unite to form the posterior cord.
The upper two anterior divisions unite to form the lateral cord.
The lower anterior division forms the medial cord.
Cords are related to axillary artery – lateral, medial and posterior.
5. Branches:
Branches are given off from roots, trunks and cord.
Branches from roots are Dorsal scapular – C5 and Long thoracic – C5, C6 and C7.
From trunks – Only upper trunk gives branches – Supra scapular-C5, C6 and Nerve to subclavius – C5, C6.
Location of Brachial Plexus:
Roots and Trunks:
Lie in neck on scalenus medius muscle.
Divisions are behind the clavicle.
Cords and branches are in the axilla.
The roots of the plexus lie behind scalenus anterior and the lower trunk is posterior to subclavian artery.
Root of Neck:
The cords are related to the axillary artery covered by pectoralis minor and major muscles in the axillary region.
Lies above the apex of lung.
Structures arching over the apex are costo- cervical trunk and its highest intercostal branch from anterior to posterior surface.
Relations of Apex of Lung:
Lateral:
Scalenus anterior, subclavian artery and vein, Lower trunk of brachial plexus behind subclavian artery and triangle of vertebral artery.
Medial:
Vertebral bodies, Oesophagus, Trachea and Thoracic duct and recurrent laryngeal nerve on left side.
Anterior:
Great vessels of head, neck and upper limb, e.g., brachiocephalic trunk, common carotid and subclavian artery with its ascending and descending branches, e.g., vertebral, inferior thyroid and internal thoracic artery and vein.
Phrenic nerve and vagus nerve (X).
Thoracic duct and subclavian artery arches over the apex of left lung from medial to lateral side.
Thoracic duct lies behind the carotid sheath but crosses over the sympathetic chain and vertebral vessels.
Superior:
Vertebral triangle with its contents.
Cervical pleura is covered with supra pleural membrane and is a fibro muscular expansion known as diaphragm of thoracic inlet or Sibson’s fascia.
Sibson’s Fascia- (Diaphragm of Thoracic Inlet)
It is a fibro muscular membrane.
Contains muscle fibres of scalenus minimus.
Dome of cervical pleura is attached to it’s under aspect.
Attachments:
From tip of transverse process of C7 to inner border of 1st rib and its cartilage.
Function:
Helps to limit recession of soft tissues of the root of neck during inspiration and ballooning during expiration.
Posterior:
Apex of lung is related to neck of 1st rib and structures passing infront of neck are – from medial to lateral. Sympathetic trunk with its inferior cervical ganglion.
V – Superior inter costal vein
A – Superior inter costal artery
N – Ascending branch of T1 spinal nerve joins with C8 and forms lower trunk of branchial plexus.
Term Paper # 3. Subclavian Artery of the Neck:
Supplies:
Upper limb, breast, anterior thoraco abdominal wall, considerable part of neck and brain.
Origin or Commencement:
Right subclavian artery commences from brachiocephalic artery behind right sternoclavicular joint.
Relations of Subclavian Artery:
Left subclavian artery commences from arch of aorta.
Termination:
It terminates at the lateral border of first rib by becoming the axillary artery.
Parts:
Divided by scalenus anterior muscle into three parts:
Ist part medial to muscle
IInd part behind the muscle
IIIrd part lateral to muscle.
Cervical part of subclavian artery arches over the apex of lung, cervical pleura and supra pleural membrane – it will be posterior relation for all 3 parts of subclavian artery.
Branches of Subclavian Artery:
1. Vertebral artery
2. Internal thoracic artery
3. Thyrocervical trunk – Inferior thyroid artery, Suprascapular artery and Transverse cervical artery.
4. Costo cervical trunk – Superior intercostal artery and Deep cervical artery.
5. Dorsal scapular artery – occasionally present, goes posteriorly along the medial border of scapula and takes part in the anastmosis around the scapula with subscapular artery at the inferior angle of scapula.
Term Paper # 4. Vertebral Artery of the Neck:
Branch of 1st part of subclavian artery with in the vertebral triangle.
It Supplies:
i. Visual area of cerebrum
ii. Hind brain, cerebellum, pons and medulla
iii. Spinal cord
iv. Sub-occipital muscles
v. Bones and meninges.
Parts:
It is divided into four parts according to its anatomical location.
Course:
Passes upwards within the vertebral triangle (Ist part)
Crosses transverse – process of C7 vertebra.
Enters the foramen – transversarium of C6 vertebra.
Passes upwards via foramen transversarium of all cervical vertebrae (IInd part).
Passes behind the lateral mass of atlas and lies on the posterior arch of atlas (IIIrd part).
Separated by posterior arch by dorsal rami of C1 – suboccipital nerve.
Passes upwards, medially and pierce the posterior adanto-occipital membrane and enters the cranial cavity via foramen magnum.
Within the cranial cavity artery lies anterior to the medulla oblongata, i.e. (IVth part).
Termination:
At the lower border of pons vertebral artery of both sides unite to form basilar artery.
Part of Vertebral Artery:
First Part:
Found within vertebral triangle.
Relations:
Anterior:
1. Common carotid artery
2. Vertebral vein
3. Inferior thyroid artery – lymphatic duct right side and thoracic duct on left side.
Posterior:
1. Transverse process of C7 vertebra
2. Ventral rami of C7 and C8 nerves
3. Inferior cervical sympathetic ganglion.
Second Part:
Found within the foramen transversarium of C1 to C6 vertebra.
Accompanied by vertebral vein and sympathetic plexus of nerves.
It crosses the cervical spinal nerves anteriorly.
Third Part:
Found within sub-occipital triangle.
Surrounded by plexus of veins and nerves.
Lies on posterior arch of atlas.
Between arch and artery lies C1 nerve – dorsal rami (sub-occipital nerve).
Fourth Part:
Found within the cranial cavity.
Enters the cranium via foramen magnum.
Lies anterior to hypoglossal nerve and medulla oblongata.
This part of artery is present in subarachnoid space, after piercing dura and arachnoid matter in the foramen magnum.
Branches of Vertebral Artery:
First Part:
No branches.
Second Part:
Spinal branches to supply spinal cord, meningies and bones they enter through inter vertebral foramen.
Third Part:
Muscular branches to sub-occipital muscles.
Fourth Part:
1. Meningeal branches – to duramater of posterior cranial fossa.
2. Posterior spinal artery supplies posterior 1/3 of spinal cord.
3. Anterior spinal artery supplies anterior 2/3 of spinal cord.
4. Posterior inferior cerebellar artery.
5. Medullary branches to supply medulla oblongata.