Week 23 - Anterior Neck Flashcards
How many cervical vertebrae form the cervical region of the vertebral column?
Seven cervical vertebrae
What do the stacked vertebral bodies of the cervical vertebrae support?
The head
What type of joints provide flexibility for head positioning in the cervical region?
Craniovertebral joints
What are the characteristics of typical cervical vertebrae (3rd–6th)?
- Small vertebral body
- Longer from side to side than anteroposteriorly
- Superior surface is concave
- Inferior surface is convex
- Large and triangular vertebral foramen
- Transverse processes include foramina transversaria
- Superior facets directed superoposteriorly
- Inferior facets directed inferoposteriorly
- Short spinous processes, bifid in individuals of European heritage
What is unique about the C1 vertebra (atlas)?
It is a ring-like, kidney-shaped bone lacking a spinous process or body
What does the C2 vertebra (axis) feature that is notable?
A peg-like dens (odontoid process) projecting superiorly from its body
What is the vertebra prominens and why is it named so?
C7, named for its long spinous process, which is not bifid
Where does the hyoid bone lie in the neck?
At the level of the C3–C4 vertebrae
What is the shape of the hyoid bone and its significance?
U-shaped, derived from the Greek word hyoeidçs, meaning ‘shaped like the letter upsilon’
How is the hyoid bone suspended?
By muscles connecting it to the mandible, styloid processes, thyroid cartilage, manubrium of the sternum, and scapulae
What are the main components of the hyoid bone?
- Body
- Greater horns
- Lesser horns
What is the approximate width and thickness of the body of the hyoid?
Approximately 2.5 cm wide and 1 cm thick
What is the function of the hyoid bone?
Serves as an attachment for anterior neck muscles and a prop to keep the airway open
What connects the greater horns to the body of the hyoid in young people?
Fibrocartilage
What may happen to the greater horns of the hyoid in older people?
They are usually united by bone
What is the lesser horn of the hyoid and how is it connected?
A small bony projection connected to the body by fibrous tissue and sometimes to the greater horn by a synovial joint
True or False: The hyoid bone articulates with other bones.
False
What is the carotid sheath?
A tubular fascial investment that extends from the cranial base to the root of the neck
What layers of fascia does the carotid sheath blend with anteriorly?
The investing and pretracheal layers of fascia
What layer of fascia does the carotid sheath blend with posteriorly?
The prevertebral layer of fascia
What structures are contained within the carotid sheath? List them.
- Common carotid artery
- Internal carotid artery
- Internal jugular vein
- Vagus nerve (CN X)
- Some deep cervical lymph nodes
- Carotid sinus nerve
- Sympathetic nerve fibers (carotid peri-arterial plexuses)
Where does the carotid sheath extend to superiorly?
The cranial base (basiocciput)
Where does the carotid sheath communicate inferiorly?
With the mediastinum of the thorax
True or False: The carotid sheath represents potential pathways for the spread of infection and extravasated blood.
True
Fill in the blank: The carotid sheath is a tubular fascial investment that extends from the _______ to the root of the neck.
[cranial base]
What are the main contents of the sternocleidomastoid region?
Sternocleidomastoid muscle, superior part of external jugular vein, greater auricular nerve, transverse cervical nerve
This region is primarily associated with the sternocleidomastoid muscle and various nerves and veins.
What does the lesser supraclavicular fossa contain?
Inferior part of internal jugular vein
This area is significant for the drainage of the internal jugular vein.
What are the main contents of the posterior cervical region?
Trapezius muscle, cutaneous branches of posterior rami of cervical spinal nerves, suboccipital region
The suboccipital region lies deep to the superior part of this region.
What structures are found in the occipital triangle of the lateral cervical region?
Part of external jugular vein, posterior branches of cervical plexus of nerves, spinal accessory nerve (CN XI), cervicodorsal trunk, cervical lymph node
This triangle contains important vascular and neural structures.
What is found in the omoclavicular (subclavian) triangle?
Subclavian artery (third part), trunks of brachial plexus, part of subclavian vein, suprascapular artery, supraclavicular lymph nodes
This triangle is important for its vascular connections and lymphatic drainage.
What are the main contents of the submandibular (digastric) triangle?
Submandibular gland, submandibular lymph nodes, hypoglossal nerve (CN XII), mylohyoid nerve, parts of facial artery and vein
The submandibular gland nearly fills this triangle.
What is contained in the submental triangle?
Submental lymph nodes and small veins that unite to form anterior jugular vein
This area is important for lymphatic drainage from the chin and floor of the mouth.
What structures are found in the carotid triangle?
Carotid sheath containing common carotid artery and its branches, internal jugular vein and its tributaries, vagus nerve, external carotid artery and its branches, hypoglossal nerve (CN XII), superior root of ansa cervicalis, spinal accessory nerve (CN XI), thyroid gland, larynx, pharynx, deep cervical lymph nodes, branches of cervical plexus
This triangle contains vital structures for vascular and nervous supply to the head and neck.
What muscles are located in the muscular (omotracheal) triangle?
Sternothyroid and sternohyoid muscles
This triangle also contains the thyroid and parathyroid glands.
What is the origin of the mylohyoid?
Suprahyoid Muscle
Mylohyoid line of mandible
What is the insertion of the mylohyoid?
Suprahyoid Muscle
Mylohyoid raphe and body of hyoid
What is the innervation of the mylohyoid?
Suprahyoid Muscle
Nerve to mylohyoid
- a branch of inferior alveolar nerve (from mandibular nere CN V3)
What are the main actions of the mylohyoid?
Suprahyoid Muscle
Elevates hyoid, floor of mouth, and tongue during swallowing and speaking
What is the origin of the Geniohyoid?
Suprahyoid Muscles
Inferior mental spine of mandible
What is the insertion of the Geniohyoid?
Suprahyoid Muscles
Body of Hyoid
What is the innervation of the Geniohyoid?
Suprahyoid Muscles
C1 via hypoglossal nerve (CN XII) and nerve to geniohyoid
What are the main actions of the Geniohyoid?
Suprahyoid Muscles
- Pulls hyoid anterosuperiorly
- Shortens floor of mouth
- Widens Pharynx
What is the origin of Stylohyoid?
Suprahyoid Muscles
Styloid process of temporal bone
What is the insertion of Stylohyoid?
Suprahyoid Muscles
Body of Hyoid
What is the innervation of Stylohyoid?
Suprahyoid Muscles
Stylohyoid (preparotid) branch of facial nerve (CN VII)
What are the main actions of Stylohyoid?
Suprahyoid Muscles
Elevates and retracts hyoid, thus elongating floor of mouth
What is the origin of the Anterior belly of Digastric?
Suprahyoid Muscle
Digastric fossa of mandible
What is the innervation of the Anterior belly of Digastric?
Suprahyoid Muscle
Nerve to mylohyoid (branch of inferior alveolar nerve)
What is the origin of the Posterior belly of Digastric?
Suprahyoid Muscle
Mastoid notch of temporal bone
What is the innervation of the Posterior belly of Digastric?
Suprahyoid Muscle
Digastric (preparotid) branch of facial nerve (CN VII)
What is the Insertion of the Digastric?
Suprahyoid Muscle
Intermediate tendon to body & greater horn of hyoid
What are the main actions of the Digastric?
Suprahyoid Muscle
- Working with infrahyoid muscles
- Depresses mandible against resistance
- Elevates and steadies hyoid during swallowing and speaking
What is the origin of Sternohyoid?
Infrahyoid Muscles
Manubrium of sternum & medial end of clavicle
What is the origin of Omohyoid?
Infrahyoid Muscles
Superior border of scapula near suprascapular notch
What is the origin of Sternothyroid?
Infrahyoid Muscles
Posterior surface of manubrium of sternum
What is the origin of Thyrohyoid?
Infrahyoid Muscles
Oblique line of thyroid cartilage
What is the insertion of Sternohyoid?
Infrahyoid Muscles
Body of hyoid
What is the insertion of Omohyoid?
Infrahyoid Muscles
Inferior border of hyoid
What is the insertion of Sternothyroid?
Infrahyoid Muscles
Oblique line of thyroid cartilage
What is the insertion of Thyrohyoid?
Infrahyoid Muscles
- Inferior border of body
- Greater horn of hyoid
What is the innervation of Sternohyoid?
Infrahyoid Muscles
C1-C3 by a branch of ansa cervicalis
What is the innervation of Omohyoid?
Infrahyoid Muscles
C1-C3 by a branch of ansa cervicalis
What is the innervation of Sternothyroid
Infrahyoid Muscles
C2 & C3 by a branch of ansa cervicalis
What is the innervation of Thyrohyoid?
Infrahyoid Muscles
C1 via hypoglossal nerve (CN XII) and nerve to thyrohyoid
What are the main actions of Sternohyoid?
Infrahyoid Muscles
Depresses hyoid after elevation during swallowing
What are the main actions of Omohyoid?
Infrahyoid Muscles
Depresses, retracts, and steadies hyoid
What are the main actions of Sternothyroid
Infrahyoid Muscles
Depresses hyoid and larynx
What are the main actions of Thyrohyoid?
Infrahyoid Muscles
Depresses hyoid and elevates larynx
What are the arteries supplying blood to the thyroid?
Arteries supplying blood to the thyroid include:
* Subclavian ⇒ Thyrocervical trunk ⇒ Inferior thyroid arteries
* External carotid ⇒ Superior thyroid arteries
* Unpaired thyroid ima artery (10%)
Which veins drain the thyroid gland?
Veins draining the thyroid include:
* Superior thyroid ⇒ IJV
* Middle thyroid ⇒ IJV
* Inferior thyroid ⇒ Brachiocephalic veins (posterior to manubrium)
What is the function of the thyroid plexus of veins?
The thyroid plexus of veins collects blood from the thyroid gland and drains into the superior, middle, and inferior thyroid veins.
Fill in the blank: The unpaired thyroid ima artery contributes _______ of the blood supply to the thyroid.
10%
Where does lymph drainage from the thyroid occur?
Lymph drainage from the thyroid occurs in:
* Paratracheal nodes
* Deep cervical nodes
True or False: The inferior thyroid vein drains into the internal jugular vein (IJV).
False
Which arteries anastomose within the thyroid gland?
The superior thyroid arteries and inferior thyroid arteries anastomose within the gland.
Where does the thyroid gland lie in relation to the sternothyroid and sternohyoid muscles?
Deep to sternothyroid & sternohyoid muscles
What is the vertebral level of the thyroid gland?
C5-T1
What are the main structural components of the thyroid gland?
Right & left lobes, thin isthmus, fibrous capsule
Where are the right and left lobes of the thyroid located?
Anterolat to larynx & trachea
What is the position of the thin isthmus of the thyroid gland?
Ant. to 2nd & 3rd tracheal rings
What surrounds the thyroid gland?
Fibrous capsule
What type of connective tissue attaches the thyroid capsule to the cricoid cartilage and superior tracheal rings?
Dense connective tissue
What forms the loose sheath surrounding the thyroid capsule?
Visceral portion of pretracheal layer of deep cervical fascia
What is the origin of the Longus colli muscle?
Anterior tubercle of C1 vertebra (atlas); bodies of C1–C3 and transverse processes of C3–C6 vertebrae
The Longus colli muscle is located in the neck region.
What is the insertion point of the Longus colli muscle?
Bodies of C5–T3 vertebrae; transverse processes of C3–C5 vertebrae
This muscle spans several cervical vertebrae.
Which spinal nerves innervate the Longus colli muscle?
Anterior rami of C2–C6 spinal nerves
These nerves are responsible for the motor function of the muscle.
What is the primary action of the Longus colli muscle?
Flexes neck with rotation (torsion) to opposite side if acting unilaterally
This indicates its role in neck movement and stability.
What is the origin of the Anterior scalene muscle?
Transverse processes of C3–C6 vertebrae
What is the insertion point of the Anterior scalene muscle?
1st rib
Which cervical spinal nerves innervate the Anterior scalene muscle?
C4–C6
What is the primary function of the Anterior scalene muscle?
Flexes neck laterally; elevates 1st rib during forced inspiration
What is the origin of the Rectus capitis lateralis?
Jugular process of occipital bone
The Rectus capitis lateralis is involved in stabilizing the head.
What is the insertion point of the Rectus capitis lateralis?
Transverse process of atlas (C1 vertebra)
This muscle helps in flexing the head.
Which spinal nerves are associated with the Rectus capitis lateralis?
Branches from loop between C1 and C2 spinal nerves
These branches are crucial for muscle innervation.
What is the primary action of the Rectus capitis lateralis?
Flexes head and helps stabilize it
It plays a key role in maintaining head posture.
What is the origin of the Splenius capitis?
Inferior half of nuchal ligament and spinous processes of superior six thoracic vertebrae
This muscle acts on the head and neck.
What is the insertion point of the Splenius capitis?
Lateral aspect of mastoid process and lateral third of superior nuchal line
It connects to important structures on the skull.
Which spinal nerves innervate the Splenius capitis?
Posterior rami of middle cervical spinal nerves
These rami are essential for the function of this muscle.
What are the actions of the Splenius capitis?
Laterally flexes and rotates head and neck to same side; acting bilaterally, extends head and neck
This muscle has both unilateral and bilateral actions.
What is the origin of the Levator scapulae?
Posterior tubercles of transverse processes C2–C6 vertebrae
This muscle is important for scapular movements.
What is the insertion point of the Levator scapulae?
Superior part of medial border of scapula
It plays a role in the positioning of the scapula.
Which nerves innervate the Levator scapulae?
Dorsal scapular nerve C5 and cervical spinal nerves C3 and C4
These nerves are vital for muscle control.
What is the primary action of the Levator scapulae?
Downward rotation of scapula and tilts its glenoid cavity inferiorly by rotating scapula
It helps in positioning the scapula for arm movements.
What is the origin of the Middle scalene muscle?
Posterior tubercles of transverse processes of C5–C7 vertebrae
The Middle scalene originates from the cervical vertebrae.
What is the insertion point of the Middle scalene muscle?
Superior surface of 1st rib; posterior to groove for subclavian artery
This indicates where the muscle attaches to the rib.
Which nerves innervate the Middle scalene muscle?
Anterior rami of cervical spinal nerves
Specifically, it is innervated by the anterior rami of the cervical spinal nerves.
What are the actions of the Middle scalene muscle?
Flexes neck laterally; elevates 1st rib during forced inspiration
These actions indicate its role in neck movement and breathing.
What is the origin of the Posterior scalene muscle?
External border of 2nd rib
This is where the Posterior scalene muscle starts.
Which nerves innervate the Posterior scalene muscle?
Anterior rami of cervical spinal nerves C7 and C8
This specifies the spinal nerves responsible for its innervation.
What are the actions of the Posterior scalene muscle?
Flexes neck laterally; elevates 2nd rib during forced inspiration
The muscle assists in neck flexion and rib elevation during breathing.
What is the insertion of the Posterior scalene muscle?
Posterior tubercles of transverse processes of C5–C7 vertebrae
Where does the Longus capitis originate?
Basilar part of occipital bone
The Longus capitis is a muscle located in the neck region.
What is the insertion point of the Longus capitis?
Anterior tubercles of C3–C6 transverse processes
This muscle helps in flexing the head.
Which spinal nerves innervate the Longus capitis?
Anterior rami of C1–C3 spinal nerves
These nerves are responsible for motor control of the muscle.
What is the function of the Longus capitis?
Flex head
Flexion of head = anterior (or lateral) bending of the head relative to the vertebral column at the atlanto-occipital joints.
Where does the Rectus capitis anterior originate?
Base of cranium, just anterior to occipital condyle
This muscle is also involved in head movement.
What is the insertion point of the Rectus capitis anterior?
Anterior surface of lateral mass of atlas (C1 vertebra)
The atlas is the first cervical vertebra.
Which spinal nerves innervate the Rectus capitis anterior?
Branches from loop between C1 and C2 spinal nerves
These branches provide motor innervation to the muscle.
What is the function of the Rectus Capitis anterior?
Flex head
Flexion of head = anterior (or lateral) bending of the head relative to the vertebral column at the atlanto-occipital joints.
