Padalecki 2 Flashcards
- Junctional area between the thorax and the neck and is described as being the cervical side of the superior thoracic aperture
- Although not an anatomical boundary, many of the structures lie deep to the clavicle
Root of the Neck
Superior Thoracic Aperture Boundaries
a. Manubrium
b. First rib
c. Body of the first thoracic vertebra
- Origin
a. Right - brachiocephalic trunk
b. Left - arch of aorta - Terminates at lateral border of first rib becoming the axillary artery
- Located superior to first rib in the groove for the subclavian artery
- Divided into three parts by the anterior scalene muscle
Subclavian artery
Three parts and location of subclavian artery
a. First part - proximal to the anterior scalene m.
b. Second part - posterior to the anterior scalene m.
c. Third part - distal to the anterior scalene muscle
Branches from first part of subclavian artery
(1) Vertebral artery - usually enters transverse foramen of sixth cervical vertebra
(2) Internal thoracic artery
(3) Thyrocervical trunk
(a) Inferior thyroid artery
[1] Ascending cervical a. (may
branch off other arteries) (b) Transverse cervical artery
(c) Suprascapular artery
Branches from second part of subclavian artery
(1) Costocervical trunk
(a) Supreme intercostal a. - supplies upper two posterior
intercostal spaces
(b) Deep cervical a. - ascends to supply intrinsic back muscles in
the neck
Branches from third part of subclavian artery
Dorsal scapular a., which is not always present
- Superior to the first rib and cervical pleura
- Anterior to the anterior scalene muscle
- Tributaries
a. External jugular v.
b. Transverse cervical v. - Joins internal jugular v. to form brachiocephalic vein
Subclavian Vein
- Enters neck to the left of the midline, dorsal to the esophagus
- Arches upward to the left and turns anteriorly
- Passes between vertebral artery (posterior) and carotid sheath (anterior)
- Ends at the junction of the left subclavian and left internal jugular veins
Thoracic Duct
- Rises above the level of the first costal cartilage
2. Subject to injury from trauma to the neck
Cervical Pleura
Origin of cervical plexus
- Ventral primary rami of C1 - C4
2. Adjacent rami are connected in the form of loops
Cutaneous branches of cervical plexus
- From C2 and C3
a. Great auricular n.
b. Transverse cervical n.
c. Lesser occipital - From C3 and C4
a. Supraclavicular n.
Muscular branches of cervical plexus
- Ansa cervicalis
a. C1-C3
- Superior root C1
- Inferior root C2-C3
b. Innervates infrahyoid muscles, except thyrohyoid muscle (C1) - Contribution to phrenic nerve
a. C3-C4
b. Innervates diaphragm
Cranial nerves associated with cervical plexus
- Hypoglossal nerve
2. Accessory nerve
Fibers from C1 accompany CN XII high in the neck and gives off three branches
(1) To geniohyoid muscle
(2) To thyrohyoid muscle
(3) Superior root of ansa cervicalis
Hypoglossal nerve
Afferents follow the cranial nerve to reach trapezius and sternocleidomastoid muscles, but are NOT fiber components of it.
Accessory nerve
- Superior cervical - level of C2 and C3 superior to bifurcation of common carotid
- Middle cervical - level of C6 anterior to the vertebral artery
- Vertebral - associated with the origin of the vertebral artery
- Inferior cervical - above the neck of the first rib posterior to the vertebral artery
a. Stellate ganglion - inferior cervical and first thoracic
Ganglia of Sympathetic Trunk
- Loop of sympathetic trunk passing ventral to subclavian artery
- Connects inferior cervical to either the vertebral or middle cervical ganglia
Ansa Subclavia of Sympathetic Trunk
- Gray rami to cervical nerves
- Cardiac branches to cardiac plexus
- Visceral branches to pharynx, larynx, thyroid, parathyroid, trachea and
esophagus - Plexuses - follow arteries into head
a. Internal carotid
b. External carotid
c. Vertebral
Distribution of branches of Sympathetic Trunk
The viscera of the neck is enclosed by a sheath of connective tissue
Visceral Sheath
a. Forms anterior portion of the visceral sheath
b. Covers anterior aspect of larynx and trachea
c. Envelops the thyroid gland
d. Attachments
(1) Superior - the hyoid bone
(2) Inferior - the pericardial sac
Pretracheal fascia
a. Forms posterior portion of the visceral sheath
b. Covers posterior aspect of pharynx and esophagus c. Attachments
(1) Superior - pharyngeal tubercle on basilar part of occipital bone
(2) Inferior - blends in with fascia in posterior mediastinum
Buccopharyngeal fascia
- Enclosed in the pretracheal fascia
- Components
a. Two lateral lobes
b. Isthmus
(1) Overlies tracheal cartilage 2-4
c. Pyramidal lobe may be present
Thyroid Gland
a. Anterior - infrahyoid muscles
b. Posterior and medial - larynx and trachea; esophagus
c. Lateral - carotid sheath and its contents
Relationships of thyroid gland
Arterial supply of thyroid gland
a. Superior thyroid a. - branch from the external carotid a
b. Inferior thyroid a. - branch
from the thyrocervical trunk of the subclavian a.
c. Thyroid ima (rarely present)
from either the brachiocephalic trunk or arch of the aorta
Venous drainage of thyroid gland
- Superior thyroid v. - to the internal jugular v
- Middle thyroid v. - to the internal jugular v.
- Inferior thyroid v. - to the brachiocephalic v.
Lymphatics of the thyroid gland go to _______.
To deep cervical nodes which follow the internal jugular vein
- Four in number; superior and inferior parathyroids
- Embedded in the posterior surface of the thyroid glands
- Small, oval and separated from thyroid tissue by a connective tissue capsule
- Supplied mainly by the inferior thyroid artery
Parathyroid Glands
- Begins below the level of cricoid cartilage (C6)
- Located anterior to the esophagus; posterior to the isthmus and medial to the lobes of the thyroid gland
- Composition
a. āCā-shaped cartilage rings
b. Trachealis muscle posteriorly
c. Mucous membrane - Innervation - recurrent branch of the vagus n.
Trachea
- Begins at the level of the cricoid cartilage
- Direct continuation of the pharynx
- Relationships
a. Anterior - trachea b. Posterior
(1) Retrovisceral space
(2) Vertebral column - Innervation - recurrent branches of the vagus n. to skeletal muscle of upper esophagus
a. Nerves ascend in tracheo-esophageal groove
Esophagus
- Follow the course of the sternocleidomastoid m.
- Drain the superficial lymph nodes of the neck and face to include:
a. Parotid nodes
b. Posterior auricular nodes
c. Occipital nodes - Empties into the deep cervical lymph nodes
Superficial Cervical Lymph Nodes
- Follow the course of the internal jugular vein
- Drain nodes of the face and neck to include:
a. Submandibular nodes
b. Submental nodes - Empties in the into the right lymphatic duct and the thoracic duct on the left side
Deep Cervical Lymph Nodes
- A sleeve of connective tissue that encloses the structures of the neck except for the platysma m. and the external jugular vein
- Continues on the face as the parotid fascia
- Attached posteriorly to the superior nuchal line, ligamentum nuchae and
the spine of the 7th cervical vertebra - From its posterior attachment
a. The fascia splits into two laminae to enclose the trapezius muscle b. Fuses into a single layer forming the roof of the posterior cervical
triangle
c. Splits again to enclose the sternocleidomastoid muscle
d. Fuses into a single layer covering the anterior cervical triangle and joins
its counterpart from the other side at the mid-line of the neck - Attaches anteriorly to the manubrium, clavicle and mandible
Investing fascia
- Encloses vertebral column and associated musculature
- Forms the floor of the posterior cervical triangle
- Lateral extension in the root of the neck is axillary sheath
- Attachments
a. Superior - basilar portion of the occipital bone
b. Inferior - blends with fascia of the thorax
c. Posterior - ligamentum nuchae merging with the origin of the investing
fascia
Prevertebral fascia
- Pretracheal fascia - anterior sheath
2. Buccopharyngeal fascia - posterior sheath
Visceral Sheath
- Tubular enclosure of the common and internal carotid arteries, internal jugular vein and vagus nerve
Carotid Sheath
