Head and Neck Anatomy II

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Questions and Answers

What is the primary effect of a surgical phrenic nerve crush?

Short-term paralysis

Immediate restoration of nerve function

Increased nerve sensitivity

Longer period of paralysis (correct)

What does the superior cervical ganglion form a plexus around?

Inferior thyroid artery

Vertebral arteries

Subclavian arteries

Internal and external carotid arteries (correct)

Which structures do the cervical sympathetic trunk lie in relation to?

Behind the prevertebral fascia

In front of the carotid arteries

Adjacent to the vertebral arteries

Behind the carotid sheaths (correct)

Which symptom is NOT characteristic of Horner's syndrome?

Hyperhidrosis Signup and view all the answers

Horner's syndrome results from an interruption of which anatomical structure?

Cervical sympathetic trunk Signup and view all the answers

Enophthalmos in Horner's syndrome refers to which condition?

Sinking of the eyeball into the cavity Signup and view all the answers

Which ganglion forms a plexus around the inferior thyroid artery?

Middle cervical ganglion Signup and view all the answers

What causes ptosis in Horner's syndrome?

Loss of sympathetic innervation to the eyelid Signup and view all the answers

What is the role of the cervical sympathetic trunk?

Sympathetic nerve pathways Signup and view all the answers

Anhidrosis in Horner's syndrome is characterized by which condition?

Reduced sweating on the face Signup and view all the answers

What is the primary distinguishing characteristic of the superficial fascia?

It has a varying amount of fat. Signup and view all the answers

Which muscle is primarily associated with the superficial fascia of the neck?

Platysma Signup and view all the answers

What is the function of the platysma muscle?

To depress the mandible. Signup and view all the answers

Which layer of fascia surrounds the sternocleidomastoid and trapezius muscles?

Investing layer Signup and view all the answers

What is the main role of the deep fascia in the neck?

Covers the muscles and neurovascular structures. Signup and view all the answers

Which of the following muscles is NOT covered by the investing layer of deep fascia?

Supraspinatus Signup and view all the answers

From where does the investing layer of the deep fascia extend superiorly?

Superior nuchal line Signup and view all the answers

What is one of the functional roles of the deep cervical fascia?

Creating muscular compartments. Signup and view all the answers

Which nerve supplies the platysma muscle?

Facial nerve Signup and view all the answers

Where does the platysma muscle extend from?

Pectoralis major and deltoid to the facial skin. Signup and view all the answers

Which component is NOT found in the superficial fascia of the neck?

Bone Signup and view all the answers

What structure is NOT covered by deep cervical fascia?

Epidermis Signup and view all the answers

Which movement is NOT facilitated by the deep fascia of the neck?

Extending the spine Signup and view all the answers

What role does the superficial fascia play in relation to blood vessels?

It aids in venous return. Signup and view all the answers

What is the inferior boundary of the neck?

Inferior border of the mandible Signup and view all the answers

Which structures are primarily found in the anterior region of the neck?

Pharynx, esophagus, larynx, and trachea Signup and view all the answers

What is the significance of Langer's lines in surgical operations?

Incisions made parallel to them heal better with less scarring. Signup and view all the answers

Which layers comprise the cervical fascia?

Superficial fascia and deep fascia Signup and view all the answers

What structure can be palpated in the posterior region of the neck?

External occipital protuberance Signup and view all the answers

Which of the following is NOT identified as a structure in the lateral regions of the neck?

Thyroid gland Signup and view all the answers

What is the role of the cervical plexus in the neck?

It supplies sensory and motor innervation to the neck region. Signup and view all the answers

Which of the following is a key component of the neck's anterior region?

Common carotid artery Signup and view all the answers

Which structure is NOT typically part of the cervical plexus?

Axillary nerve Signup and view all the answers

What can typically be found in the lateral regions of the neck during palpation?

External jugular vein Signup and view all the answers

Which of the following best describes the neck?

A tubular constriction serving as a conduit. Signup and view all the answers

Which cranial nerves are typically found in the anterior region of the neck?

Vagus and hypoglossal nerves Signup and view all the answers

What is the primary purpose of the deep fascia in the neck?

To compartmentalize structures within the neck. Signup and view all the answers

Which spinal segments are primarily responsible for the cutaneous innervation of the neck?

C2, C3, C4 Signup and view all the answers

The phrenic nerve is formed from the anterior rami of which spinal segments?

C3-C5 Signup and view all the answers

What area does the lesser occipital nerve (C2) supply?

Posterosuperior scalp Signup and view all the answers

The supraclavicular nerves arise from which spinal segments?

C3 and C4 Signup and view all the answers

Which of the following nerves supplies the lateral neck and upper thoracic region?

Transverse cervical nerve Signup and view all the answers

Which nerve is the thickest cutaneous nerve in the body?

Greater occipital nerve Signup and view all the answers

Which branches of the cervical plexus are primarily sensory?

Superficial branches Signup and view all the answers

What is the primary function of the ansa cervicalis?

Supply infrahyoid muscles Signup and view all the answers

What is the consequence of a cervical plexus block regarding the diaphragm?

Short-term paralysis of one side Signup and view all the answers

Which nerve supplies the skin over the auricle and parotid gland?

Great auricular nerve Signup and view all the answers

Which nerve provides innervation to the diaphragm?

Phrenic nerve Signup and view all the answers

Which fascia surrounds the visceral organs in the neck?

Pretracheal fascia Signup and view all the answers

What is the main concern when performing a cervical plexus block on patients with pulmonary conditions?

Diaphragm paralysis Signup and view all the answers

What does the deep cervical plexus block anesthetize?

Muscles of the neck Signup and view all the answers

What is the function of the prevertebral fascia?

Encloses intrinsic muscles of the neck Signup and view all the answers

Which of the following structures is located within the carotid sheath?

Internal jugular vein Signup and view all the answers

What does the term 'musculofascial collar' refer to?

Muscles and investing fascia involved in head rotation Signup and view all the answers

What is a major clinical significance of fascial spaces in the neck?

They facilitate the spread of infections. Signup and view all the answers

The retropharyngeal space is bound anteriorly by which structure?

Pharyngeal wall Signup and view all the answers

In which compartment would you find pharyngeal and laryngeal structures?

Visceral compartment Signup and view all the answers

Which of the following compartments contains lymphatic vessels and nerves?

Neurovascular compartment Signup and view all the answers

The pretracheal fascia is primarily involved with which structures?

Visceral organs Signup and view all the answers

Which structure is closely related to the parapharyngeal space?

Pharynx Signup and view all the answers

What is the primary role of the investing fascia?

Surround muscles of the neck Signup and view all the answers

Which layer of fascia is involved in allowing carotid sheath structures to glide during neck movement?

Prevertebral fascia Signup and view all the answers

The retropharyngeal space extends from which region to the diaphragm?

Base of skull Signup and view all the answers

Study Notes

Learning Outcomes

Understand surface and sectional anatomy of the neck.
Describe layers of deep cervical fascia and fascial spaces, noting their clinical significance.
Explain cutaneous supply and cervical plexus of the neck, including cervical plexus block.

Anatomy of the Neck

The neck extends from the base of the skull to the inferior border of the mandible and the superior thoracic aperture.
Serves as a conduit for structures between the head and trunk.

Divisions of the Neck

Divided into four regions:
- Anterior region: Contains strap muscles, visceral structures (pharynx, larynx, trachea, esophagus), vascular elements, cranial nerves, thyroid, and parathyroid glands.
- Right and Left Lateral regions: Include superficial muscles and cervical lymph nodes, with palpation points like the mastoid process, clavicle, and the sternocleidomastoid muscle.
- Posterior region (nucha): Involves the cervical vertebral column, spinal cord, and is palpated via features like the external occipital protuberance and the 7th cervical vertebra.

Key Structures in the Neck

Anterior region palpation points: Hyoid bone, thyroid cartilage, cricoid cartilage, tracheal rings, isthmus of the thyroid gland, thyroid lobes, suprasternal notch, and common carotid artery.
Lateral region palpation points: Sternocleidomastoid muscle, trapezius muscle, external jugular vein, and transverse process of the atlas vertebra.

Langer's Lines

Langer's lines (tension or cleavage lines) indicate the natural orientation of collagen fibers in the dermis.
Surgical incisions aligned with these lines promote better healing and reduced scarring.

Skin Characteristics

The neck skin is thin and under tension, corresponding with wrinkle lines and Langer’s lines, making incisions along these lines preferable for healing.

Fascia of the Neck

Two main layers of cervical fascia:
- Superficial fascia: Thin, subcutaneous tissue that contains the platysma muscle and various nerves, blood, and lymphatic vessels.
- Deep fascia: Covers muscles, viscera, and neurovascular structures; consists of several layers including the investing layer.

Muscles and Functions

Platysma helps in depressing the mandible and releases pressure in underlying veins for venous return.
Investing layer encases sternocleidomastoid and trapezius muscles, creating a musculofascial collar that facilitates head rotation and neck flexion.

Attachments of the Investing Layer

Superiorly connects to the superior nuchal line, lower border of the mandible, ligamentum nuchae, mastoid process, and the 7th cervical spine.### Fascial Structures of the Neck
External occipital protuberance located anteriorly to the symphysis menti.
Hyoid bone serves as an inferior landmark, alongside the manubrium, clavicle, acromion process, and spine of the scapula.

Pretracheal Fascia

Forms the visceral compartment surrounding neck organs.
Located deep to the infrahyoid strap muscles within the anterior triangle of the neck.
Provides an upward attachment to the hyoid bone and thyroid cartilage.
Encloses the thyroid gland and blends with the aorta's adventitia and carotid sheath.

Prevertebral Fascia

Encloses intrinsic neck muscles, forming the vertebral compartment.
Extends from the base of the skull down to the level of the T3 vertebra.
Prolonged laterally towards the axillary sheath.
Allows movement of the pharynx and esophagus during swallowing and neck movements.

Carotid Sheath

Surrounds crucial neurovascular structures including the internal jugular vein, carotid arteries, and vagus nerve.
Formed from a blend of connective tissues associated with investing and pretracheal fascia.
Contains sympathetic trunk situated behind the carotid sheath.

Compartmentalization of the Neck

Musculofascial collar: Involves muscles and fascia that aid in head rotation.
Muscular compartment: Holds muscles regulating swallowing and speaking.
Visceral compartment: Encloses pharynx, larynx, esophagus, trachea, and thyroid glands.
Neurovascular compartment: Contains major arteries, veins, and nerves.
Vertebral compartment: Houses vertebrae and intrinsic neck muscles facilitating neck movement.

Fascial Spaces and Infection Spread

Fascial spaces prevent adherence of structures and allow organ movement.
Facilitate the spread of infections from the mouth to neck spaces and potentially into the mediastinum.

Parapharyngeal Space

Lies postero-lateral to the pharynx, extending forward into the sublingual region.
Connected to interfascial spaces and drains lymph from the nose, throat, and jaw.
Clinical significance includes the risk of infection spreading from the mouth to the pharynx and neck.

Retropharyngeal Space

Located between the vertebral column and visceral compartment of the neck, extending from the skull base to the diaphragm.
Functions allow expansion during swallowing.
Routes infections from the mouth to the superior mediastinum, primarily from first and third molars.

Ludwig’s Angina

Condition characterized by bilateral swelling of the submental, sublingual, and submandibular spaces.
Usually results from tooth abscesses that spread pus through lingual plates.
Symptoms include hardening of the floor of the mouth, elevated tongue, and potential airway obstruction.
Requires prompt medical attention to prevent severe complications, including asphyxia and pneumonia.### Cutaneous Innervation of the Neck
Cutaneous nerves supply skin of the neck, upper thorax, scalp, and ear.
Derived from spinal segments C2, C3, and C4; C1 has no cutaneous branch.
Erb’s Point (nerve point of the neck) is located at the posterior border of the sternocleidomastoid muscle.
Anterolateral skin of the neck is supplied by ventral rami of C2, C3, and C4.
Posterior aspect of the neck is supplied by dorsal rami of C2, C3, C4, and C5.

Cutaneous Nerves of the Neck

The front and sides of the neck receive supply from four cutaneous nerves from C2, C3, and C4.
Lesser Occipital Nerve (C2): Innervates the posterosuperior scalp, posterior auricle, and upper middle neck.
Great Auricular Nerve (C2 and C3): Supplies skin over auricle, parotid gland area, and angle of the mandible.
Transverse Cervical Nerve (C2 and C3): Supplies anterior and lateral aspects of the neck.
Supraclavicular Nerves (C3 and C4): Provide sensation to skin over the suprascapular fossa and upper thoracic region.

Cervical Plexus

The cervical plexus is a network of nerve fibers formed by the anterior rami of spinal nerves C1-C4, located in the posterior triangle of the neck.
Divided into superficial (sensory) and deep (motor) branches.

Superficial Branches

Formed from C1-C4:
- Lesser occipital nerve (C2)
- Great auricular nerve (C2 and C3)
- Transverse cervical nerve (C2 and C3)
- Supraclavicular nerves (C3 and C4)

Deep Branches

Communicating branch (C1): Merges with hypoglossal nerve, innervates thyrohyoid and geniohyoid muscles.
Ansa cervicalis: A loop formed by C1 and C2-C3 roots, innervates infrahyoid muscles (omohyoid, sternohyoid, sternothyroid).
Phrenic nerve (C3-C5): Provides motor innervation to diaphragm and sensory innervation to diaphragmatic pleura and pericardium.

Muscular Branches

Innervates prevertebral muscles, sternocleidomastoid, trapezius, and scalene muscles.

Cervical Plexus Block

Used in surgical procedures such as thyroid surgery and neck operations.
Administered at the midpoint of the posterior border of sternocleidomastoid (Erb’s point).
Superficial block anesthetizes skin; deep block anesthetizes neck muscles.
Phrenic nerve blockade is avoided in pulmonary or cardiac disease patients.

Cervical Sympathetic Trunk

Located on either side of the cervical vertebral column, behind carotid sheaths.
Consists of three ganglia:
- Superior Cervical Ganglion: Forms plexus around internal and external carotid arteries.
- Middle Cervical Ganglion: Forms plexus around inferior thyroid artery.
- Inferior Cervical Ganglion: Forms plexus around vertebral and subclavian arteries.

Horner’s Syndrome

Results from interruption of sympathetic trunk, usually in upper thoracic or lower cervical regions.
Characterized by:
- Miosis (constricted pupil)
- Ptosis (drooping of upper eyelid)
- Anhidrosis (absence of sweating on face)
- Enophthalmos (sinking of eye into bony cavity)

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Test your knowledge on the surface and sectional anatomy of the neck in this Head and Neck Anatomy II quiz. Explore the structures, layers of deep cervical fascia, and their clinical implications to enhance your understanding of the neck's complex anatomy.

Head and Neck Anatomy II - Quiz

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