The anterior triangle of the neck

• It lies in front of the sternomastoid muscle .• It is bounded by :• 1- anterior border of sternomastoid muscle .

(behind)• 2- anterior midline of the neck ( in front )• 3- lower border of the mandible (base )• It is subdivided into 4 triangles by means of the

superior belly of omohyoid muscle , the anterior and posterior bellies of digastric muscle as follows :

• 1- Digastric triangle • 2- carotid triangle • 3- Muscular triangle • 4- Submental triangle

Anterior belly of digastric muscle

Posterior belly of digastric

Stylohyoid

Sternohyoid muscle

Digastric triangle Or submandibular triangle

• Outlines :• Above : the lower border of the mandible • Below & infront : the anterior belly of Digastric

muscle • Below & behind : the posterior belly of Digastric

and stylohyoid muscles . • Floor : • Anteriorly : the mylohyoid muscle • Posteriorly : part of hyoglossus muscle

Contents of the Digastric triangle

• 1- submandibular salivary gland • 2- the submandibular lymph nodes lie on the

surface of the gland • 3- facial artery deep to posterior end of

submandibular salivary gland • 4- facial vein lies superficial to submandibular

salivary gland • 5- hypoglossal nerve • 6- nerve to mylohyoid muscle

• dDigastric triangle

Carotid triangle

Muscular triangle

Anterior belly of digastric

Posterior belly of digastric

Mylohyoid muscle forms the floor of the mouth

Carotid triangle • Outlines :• Behind : the sternomastoid muscle • Infront and above : the posterior belly of digastric muscle • Infront and below : the superior belly of omohyoid

muscle • Floor : infont : the hyoglossus muscle ( above ) and the

thyrohyoid muscle (below) • Behind: the middle constrictor muscle of the pharynx

(above ) and the inferior constrictor muscle of the pharynx (below )

External carotid artery

Common carotid artery

Internal carotid artery

Contents of the Carotid triangle

• 1- The carotid sheath and its contents : • - common carotid artery : in the lower part of

the triangle .• - internal carotid artery : in the upper part of

the triangle .• Internal jugular vein : lateral • Vagus nerve : between the artery and the vein

but in a more posterior plane .

• 2- the external carotid artery : gives most of its branches in the carotid triangle ( superior thyroid artery ,lingual artery ,facial artery , ascending pharyngeal artery and occipital artery )

• 3- hypoglossal nerve • 4- Descendes cervicalis (C2,3) anterior to carotid

sheath.• 5- sympathetic trunk adherent to the posterior

wall of carotid sheath

Muscular triangle

• Outlines :• Infront : midline of the neck • Behind and above :superior belly of omohyoid

muscle • Behind and below : the sternomastoid muscle

It contains the infrahyoid muscle contain toss ,,,thyrohyoid ,,omohyoid,sternohyoid,sternothyroid

Submental triangle

• Outlines : • Infront : symphysis menti of the mandible • On each side : the anterior belly of digastric muscle • Behind ( base ) : the hyoid bone • Floor : parts of the mylohyoid muscles as they meet

each other in the median plane • Contains …………………………• 1- submental lymph nodes • 2- beginning of the anterior jugular vein

Deep Neck Space Anatomy

• Space Involving Entire Length Of Neck

• Space Limited To Above The Hyoid Bone

• Space limited To Below The Hyoid Bone

Space Involving Entire Length Of Neck

1. Retropharyngeal Space2. Danger Space

(Prevertebral Space)3. Paravertebral Space4. Carotid Sheath Space

Retropharyngeal Space

• Between visceral division of middle layer and alar division of deep layer

• Extend from skull base to T2 level

• Midline raphae• More commom in children

due to presence of retropharyngeal node

Danger Space• Between alar division and

prevetebral division of deep layer (locate posterior to retropharyngeal space)

• Extend from skull base to diaphram

• No midline raphae• Infection spread from neck

to posterior mediastinum easily

Paravertebral Space

• Between prevertebral division of deep layer and vertebral bodies

• Extend from skull base to coccyx

• Infection in this space is rare and spread slowly due to compact connective tissue

Carotid sheath Space

• Made up from all deep cervical fascia

• Infection from any deep fascia can spread to this space (lincoln High way)

Space Limit To Above The Hyoid Bone

1. Parapharyngeal Space2. Submandibular Space3. Masticator Space4. Temporal Space5. Parotid Space

Parapharyngeal Space(Lateral phryngeal Space)(Pharyngomaxillaly Space)

Boundary

• Superiorly : Skull base• Inferiorly : Hyoid bone• Laterally : Medial pterygoid m.• Medially :Buccopharyngeal fascia• Anteriorly : Submandibular space• Posteromedialy : Prevertebral fascia &

retrophryngeal space

Submandibular Space

Divided into 2 spaces by mylohyoid m.

1. Sublingual space (above mylohyoid m.)

2. Submaxillaly space (below mylohyiod m.)

• These 2 spaces can communicate each other by mylohyoid cleft

Masticator Space• Between masticator m. and

superficial layer of deep cervical fascia

(Masticator m. = massestor m.,medial and lateral pterygoid m. and temporalis muscle)

• Locate anterior and lateral to parapharyngeal space

Parotid Space

• Between parotid gl. and superficial layer of deep cervical fascia

• Infection can spread easily to parapharyngeal space due to incompleted encircle at upper inner surface of parotid gl.

Space Limit To Below The Hyoid Bone

Anterior Viseral Space (Pretracheal Space)

• Between trachea, esophagus and middle layer of deep cervical fascia

• Extend from hyoid bone to superior mediastinum