GEN ANA 2 (Laboratory): The Neck, Blood, and Lymphatics

Neck

Region of the body that lies between:

• Lower margin of the mandible

• Superior nuchal line of the occipital bone above

  AND

• Jugular/suprasternal notch

• Upper borders of the clavicle below

SUPERIOR BOUNDARY

• Anteriorly - lower border of the mandible

• Laterally - line between the gonion and mastoid temporal

• Posteriorly - inion and superior nuchal line

INFERIOR BOUNDARY

• Anteriorly - jugular notch/suprasternal notch.

• Laterally - superior border of the clavicle.

• Posteriorly - transverse line from the acromio-clavicular joint to the spinous process of the 7th cervical vertebra.

• Skin

• Superficial Fascia

• Platysma Muscles

• Superficial Nerves

• Superficial Veins

• Superficial Cervical Lymph Nodes

• Deep Cervical Fascia

What are the layers of the neck?

• External Jugular Vein

• Anterior Jugular Vein

What are the superficial veins?

1. External or Investing Layer

2. Middle or Pre-tracheal Layer

3. Internal or Prevertebral Layer

What are the layers of deep cervical fascia?

External/Investing Layer

• Completely encircles or encloses the neck including the SCM and the trapezius muscles.

• Attached posteriorly to ligamentum nuchae, forming a roof over the anterior and posterior triangles of the neck.

Middle/Pre-tracheal Layer

Encloses thyroid gland, parathyroid gland, and infrahyoid m.

Divided into two parts:

1. Prethyroid layer

2. Pretracheal layer proper

1. Prethyroid layer

2. Pretracheal layer proper

What are the 2 parts of Pre-tracheal Layer under deep cervical fascia?

Prevertebral Layer

Covers the prevertebral mucles.

Prevertebral Layer

• Above - base of skull

• Below - continues with anterior longitudinal ligament of the vertebral column

• Behind - ligamentum nuchae

• Posterior Triangle

• Anterior Triangle

What are the triangles of the neck?

Posterior Triangle

• Anterior Boundary - posterior border of the sternocleidomastoid

• Posterior Boundary - anterior border of the trapezius muscle

• Superior Boundary - meeting of trapezius and SCM at the superior nuchal line

• Inferior Boundary - superior border of the intermediate 1/3 of the clavicle

Anterior Triangle

• Anterior Boundary - median line of the neck

• Posterior Boundary - anterior border of the SCM

• Superior Boundary - inferior border of the mandible

• Roof - skin, superficial fascia, platysma and investing layer of DCF

• Occipital Triangle

• Supraclavicular/Subclavian/Omoclavicular Triangle

What are the subdivisions of the posterior triangle?

• Digastric Triangle

• Carotid Triangle

• Muscular or Inferior Carotid Triangle

• Submental Triangle

What are the subdivisions of the anterior triangle?

Cervical Plexus

A network of nerves formed by communications between the anterior rami of the upper 4 cervical nerves.

Cervical Plexus

Lies posterior to the internal jugular vein and the SCM muscle.

• Superficial/Cutaneous Branches

• Deep Branches

What are the branches of Cervical Plexus?

Ascending branches

Descending branches

What are the branches of superficial branch under cervical plexus?

Cervical Plexus - Superficial branches - Ascending branches

a. lesser occipital nerve

b. great auricular nerve

c. nervus cutaneous colli

Cervical Plexus - Superficial branches - Descending branches

a. medial supraclavicular nerve

b. intermediate supraclavicular nerve

c. lateral supraclavicular nerve

Cervical Plexus - Deep branches - Lateral branches

• Muscular branch - SCM, trapezius, levator scapula, middle and posterior scalene muscles

Cervical Plexus - Deep branches - Medial branches

Muscular branch - prevertebral muscles, infrahyoid muscles

Communicating branches to Vagus, Hypoglossal, and Sympathetic nerves

Vagus, hypoglossal, and sympathetic nerves.

Medial branches of deep branches are communicating branches to __________.

Phrenic Nerve

Most important branch, supplies the diaphragm which is the chief muscle for respiration.

• Alimentary Layer

• Respiratory Layer

• Endocrine Layer

What are the viscera of the neck?

Pharynx

Wide muscular tube that extends from the base of the skull to the 6th cervical vertebra.

Divided into three:

1. Nasopharynx

2. Oropharynx

3. Laryngopharynx

1. Nasopharynx

2. Oropharynx

3. Laryngopharynx

Pharynx is divided into three:

Esophagus

Muscular tube from pharynx to stomach.

Alimentary Layer

Pharynx

Alimentary Layer

Esophagus

Trachea

Tube-like structure within the upper chest and neck that serves as the airway that leads from larynx to bronchi.

Larynx

also known as the voice box. It is the upper extended area of the windpipe composed of catilages, ligaments, muscles lined by mucous membrane.

Respiratory Layer

Trachea

Respiratory Layer

Larynx

Endocrine Layer

Thyroid Gland

Endocrine Layer

Parathyroid Gland

Thyroid Gland

Butterfly-shaped organ with two lateral lobes. It extends from the middle thyroid cartilage to the 6th tracheal ring.

Parathyroid Gland

Two pairs of small oval bodies located posterior to the thyroid gland. It secretes a hormone which increases blood levels of calcium and calcitonin that lowers the blood levels of calcium.

Occipital Triangle (Posterior Triangle)

• Anterior - posterior border of the sternocleidomastoid muscle

• Posterior - anterior border of the trapezius muscle

• Superior - meeting of trapezius and SCM

• Inferior - superior border of the inferior belly of the omohyoid muscle

Supraclavicular/Subclavian/Omoclavicular Triangle (Posterior Triangle)

• Anterior - posterior border of the sternocleidomastoid

• Superior - inferior border of the inferior belly of the omohyoid m.

• Inferior - superior border of the intermediate 1/3 of the clavicle

Digastric Triangle (Anterior Triangle)

• Superior - lower border of the mandible

• Anterior - anterior belly of the digastric muscle

• Posterior - posterior belly of the digastric muscle

Carotid Triangle (Anterior Triangle)

• Superior - posterior belly of the digastric muscle

• Inferior - superior belly of the omohyoid muscle

• Posterior - anterior border of the SCM

Muscular or Inferior Carotid Triangle

• Supero-posterior - superior belly of the omohyoid

• Infero-posterior - anterior belly of the SCM

• Anterior - median line of the neck

Submental Triangle

• Lateral - two anterior bellies of the digastric muscles

• Posterior - hyoid bone

Arteries

Carry oxygenated blood

Veins

Carry unoxygenated blood

Pharyngeal Artery

Veins carry unoxygenated blood with the exception of _________.

• Brachiocephalic trunk

• Arch of aorta

What are the main arteries of the head and the neck?

• Carotid artery (R)

• Subclavian artery (R)

What are under the brachiocephalic trunk?

• Carotid Artery (L)

• Subclavian Artery (L)

What are under the arch of aorta?

• External Carotid Artery

• Internal Carotid Artery

What are under the right carotid artery?

1. Vertebral Artery

2. Thyrocervical Trunk

3. Costocervical Artery

What are the branches of the right subclavian artery?

Vertebral Artery

Superior part of Spinal Cord, Brainstem, Cerebellum

Thyrocervical Trunk

Thyroid, Parathyroid, Larynx, Pharynx

Costocervical Artery

Posterior neck muscles

SUPERIOR THYROID ARTERY

superior portion of thyroid gland

ASCENDING PHARYNGEAL ARTERY

soft palate, pharynx

LINGUAL ARTERY

intrinsic muscles of the tongue, floor of the mouth

FACIAL ARTERY

skin and muscles of face

OCCIPITAL ARTERY

posterior region of scalp

POSTERIOR AURICULAR ARTERY

parotid gland, ear, scalp, adjacent muscles

MAXILLARY ARTERY

maxi and mandi teeth, mandible, masseter muscle, buccinator

SUPERFICIAL TEMPORAL ARTERY

temporal region

INFERIOR HYPOPHYSEAL ARTERY

neurohypophysis

SUPERIOR HYPOPHYSEAL ARTERY

adenohypophysis

OPHTHALMIC ARTERY

orbit

ANTERIOR CHOROIDAL ARTERY

parts of midbrain, components of visual pathway

INTERNAL JUGULAR VEIN

Sigmoid Sinus, Inferior Petrosal Sinus, Meningeal Veins, Pharyngeal Venous Plexus, Common Facial Vein, Superior and Middle Thyroid Veins

SUBCLAVIAN VEIN

Anterior Jugular Vein, External Jugular Vein, Veins from the upper limb

BRACHIOCEPHALIC VEIN

Internal Jugular Vein, Subclavian Vein, Vertebral Vein, Internal Thoracic Vein

Facial

superficial part of the face, cheek

Parotid

upper and lateral parts of the face, anterior and lateral region of the scalp, external ear (anterior portion)

Occipital

posterior part of the scalp, upper neck

Mastoid

lateral parts of scalp, external ear (posterior portion)

SUBMENTAL

Tip of the tongue, Medial lower lip, Mandibular incisors and gingiva, Anterior floor of the mouth, Chin

SUBMANDIBULAR

Upper lip, Lateral lower lip, Cheek, Hard and soft palate, All teeth except mandibular incisors, Anterior gingiva (excluding mandibular incisors), Anterior 2/3 of tongue, Floor of the mouth, Sublingual and submandibular glands, Submental nodes, Anterior nasal cavity, Medial eyelids, All sinuses except - Sphenoid sinus, Posterior ethmoid sinus

Posterior Cervical Nodes

skin angle of mandible, parotid region, inferior portion of the external ear

Anterior Cervical Nodes

skin of anterior portion of neck (inferior to hyoid)

PAROTID NODES

tympanic cavity, parotid gland, auditory tube, External Auditory Meatus

RETROPHARYNGEAL NODES

Sphenoid sinus, posterior ethmoid, nasal cavity, nasopharynx, oropharynx, auditory tube, pharyngeal and tubal tonsils

Upper Deep Cervical Nodes (UDCN)

All superficial lymph nodes except

JUGULODIGASTRIC

posterior ⅓ of the tongue, etc.

JUXTACERVICAL

prelaryngeal, pretracheal, paratracheal (larynx, thyroid gland, trachea, esophagus)

Inferior Deep Cervical Nodes (IDCN)

UDCN, Jugulodigastric, Superficial, Transverse Cervical Nodes