Theme 2 Flashcards
The Neck
Atlanto-occipital joint
join between (occipital condyles of) skull and C1 Atlas
atlantoaxial joint
Joint between Axis and atlas
Synovial articulation between the (superior articular facets of the) axis and the (inferior articulating facets of the) atlas
Aritculations take place:
- Median: Dens and anterior arch C1
- Lateral: articular facts of C1 & C2
SCM
- Attachments
- Actions
- Innervation
1.
Superior:
- Mastoid process
- Superior nuchal line
Inferior:
- Manubrium sternal head
- middle 1/3 Clavicle
- -
Acting Bilaterally = flexes the neck
Acting Unilaterally = rotates the head to the opposite side and pulls up the sternum during forced inspiration
- CNXI
Trapezium Muscle
- Attachments
- Actions
- Innervation
1.
Medial:
- Superior Nuchal Line
- External Occipital Protuberance
- C1 - T12
- Scapula (Shoulder blade)
Lateral: 1/3 of Clavicle
- Elevates arm and rotates the scapula
- CNXI
What does the SCM provide to the Neck?
Provides sensory innervation to the skin on the anterior aspect of the neck
CNXI - Spinal Accessory Nerve
Through Jugular Foramen Deep to SCM - motor innervation
Emerges from posterior SCM to Levator Scapulae into Trapezius
Border of Posterior Triangle
- Posterior Border of SCM
- Middle 1/3 of Clavicle
- Anterior border of Trapezius
Muscles of the Floor of the Posterior Triangle (Superior to Inferior)
Splenius Capitis
Levator Scapulae
Sclenus Post, Medius, Ant
What are the contents of the Posterior Triangle?
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- Spinal accessory nerve
- Subclavian artery
- Brachial plexus - between scalenus med & ant
- Cutaneous nerves
- Phrenic nerve - across levator scapulae
- Omohyoid muscle
- External Jugular vein
Border of Anterior Triangle
- Anterior border of SCM
- Midline Inferior border of the Mandible
- Apex: Manubrium Sterni
What are the contents of the Anterior Triangle?
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- Cervical Plexus
- Common, External (inc. branches) & Internal Carotid
- CNXII - Hypoglossal
- Hyoid Bone
- Thyroid Gland
- Internal Jugular vein
- CNX - Vagus
What are the 4 Suprahyoid muscles? Role? Innervation?
Role: Raise Hyoid bone
- Digastric =
- Posterior Digastric belly: CNVII
- Anterior digastric belly: CNV3
- Stylohyoid - CNV3
- Mylohyoid - CNV3 Elevates hyoid bone, base of tongue & floor of the mouth
- Geniohyoid - C1 hitchhiking along CNXII
Roof of Ant. & Post. Triangles
Skin
Superficial Facia
Platysma
Deep investing fascia
What are the 4 Infrahyoid muscles? Roles? Innervation?
Action: Lower Hyoid bone
Innervation: Ana Cervicalis (C1-C3) but Thyrohyoid by fibers of C1 hitchhiking along CNXII
- Sternohyoid
- Omohyoid (omo = shoulder)
- Sternothyroid
- Thyrohyoid
1&2 = Superficial and depress the larynx
3&4 = Deep
Visceral Units
Hyoid bone
(Thyrohyoid mebrnae)
Thyroid Cartilage
(Circothyroid membrane)
Circoid membrane
Trachea
What is a plexus?
network of nerves - a branching and rejoining pattern of nerves`
Pharyngeal Plexus
CN IX X XI
Cervical Plexus
Branches & Function
Formed by Anterior rami of C1 - C4
Supplies structures in the anterior & lateral regions of the neck
- Lesser occipital: innervates the skin and the scalp posterosuperior to the auricle (C2)
- Great auricular nerve: innervates skin near concha auricle (outer ear) and external acoustic meatus (ear canal) (C2&C3)
- Transverse cervical nerve: innervates anterior region of neck (C2&C3)
- Supraclavicular nerves: innervate the skin above and below the clavicle (C3,C4)
Ansa Cervicalis
C1 -C3 (cervical plexus)
Motor supply to Infrahyoid muscles
Brachial plexus
Formed by anterior rami of C5-T1
Supplies all upper limb structures
Branches of the Vagus Nerve - CNX
Meningeal, re-enter skull through jugular foramen to supply Dura
Pharyngeal branches in pharynx + CNIX + CNXI = Pharyngeal Plexus
Superior Laryngeal: splits into internal external Laryngeal = supply Larynx & Thyroid
Recurrant Laryngeal:
Right - curves under subclavian artery & loops to ascent into the neck
Left - curves around aorta
Both Run back to supply Larynx & Thyroid
Arteries of the Roof of the Neck (Branches)
What forms the Vena Cava
2 Brachiocephalic Veins descend and =
Branches of Brachiocephalic Vein
- Inferior Thyroid
- Internal Jugular
- Subclavian
- External Jugular
- Vertebral
- Internal Thoracics
2 Lymphatic Vessels of the Root of the Neck
Thoracic Duct:
- Arises from thorax, behind oesophagus
- Drains: Lymph from Thorax & L.Arm into confluence of L. Internal Jugular Vein + L.Subclavian Vein
Right Lymphatic Duct:
Drains R.Arm into confluence of R.Internal Jugular Vein + R.Subclavian Vein
What does the Subclavian Vein receive?
It receives 3 tributaries:
- Internal thoracic vein
- External jugular vein
- Vertebral vein
Neurovascular Bundles of the Neck
Carotid Sheath:
- Common Carotid artery & branches
- Internal jugular vein
- Vagus nerve
Subclavian:
- Subclavian Artery
- Subclavian Vein
- Brachial Plexus
Pathway of Hypoglossal - CNXII
Hypoglossal Canal Descends externally to Carotid Sheath Loops under Posterior Digastric –> Ant.Triangle –> Submandibular Region
Crosses Lingual Artery
Innervates intrinsic & extrinsic muscles of tongue expect palatoglossus
Thyroid Glands
- Where do the R & L lobes join?
- Blood supply
- Venous drainage
- Innervation
- Function
- Secretes
- Isthmus
2.
- Superior Thyroid arteries (branch of ext.carotid artery)
- Inferior Thyroid arteries (branch of thyrocervical trunk)
3.
- Superior Thyroid
- Internal Jugular
- Middle Thyroid
- Inferior Thyroid
4.
- Superior Laryngeal
- Recurrent Laryngeal
- Function:
- Hormones production
- Maintenance of metabolism
- Secretes:
- Thyroid hormone
- Calcitonin
Relationships of Scalenus Anterior
Anterior:
- Phrenic Nerve
- Subclavian Vein
- CNX
- Internal Jugular
Medial:
- First part of Subclavian Artery and its Branches
- Vertebral Vein
Posterior: Second part of Subclavian Artery
Lateral:
- Third part of Subclavian Artery
- Brachial Plexus
Functions of Facia
- Support of structures
- Pathways for neurovascular structures
- Facilitates movement
- Sites of attachment for muscles
- Promotes venous drainage
- Protection
What does Superficial Fascia contain?
Tissue containing fat
Superficial Lymph Nodes
Nerves & Blood vessels to supply skin Platysma
Platysma
- What is it?
- Function
- Innervation
- Thin & wide sheet that covers anterior & lateral aspects of the neck
- Acts to tense the skin of the neck & depress mandible
- CNVII
Layers of Deep Cervical Fascia
Deep Investing Fascia completely encircles the neck & splits to pass round the Sternocleidomastoid and Trapezius muscles
Visceral/Pretracheal Fascia forms around the visceral unit of the neck (pharynx/oesophagus, larynx/trachea and thyroid gland)
Prevertebral Fascia surrounds the cervical vertebral unit (C1-C7 vertebrae, C1-C8 nerves, cervical spinal cord, anterior vertebral muscles)
Carotid Sheath
How does infection spread in fascia?
Several routes:
- Through tissue planes & spaces
- Venous routes
- Lymphatic system
Spaces: filled with loose connective tissue = vulnerable to being destroyed by infection
Communications between spaces allow infections to spread widely via lymphatic system
Lymphatic drainage of head and neck
Superficial Lymph Nodes of
Head: drain to nodes at the head-neck junction
Neck: drain to nodes along external jugular vein
Both of these drain to deep cervical nodes along the internal jugular vein
Superficial Ring of lymph drainage - Function
Submental - tip of tongue, floor of mouth, lower lip &chin
Submandibular - lower face & anterior 2/3 tongue
Parotid - skin of upper face
Mastoid - scalp & ear
Occipital - posterior scalp
Superficial cervical - superficial neck
Where do the Superficial Lymph nodes drain
Superior deep nodes & jugulo-digastric —> receives all drainage (Submandibular, Parotid, Mastoid, Superficial cervical)
Inferior deep nodes & jugulo-omohyoid —> receives more anterior & posterior drainage (Submental & Occipital)
