BY: DR. AYAT

ELDOMOUKY

Muscluar triangles of ……………….the

neck

POSTERIOR TRIANGLE

BOUNDARIES

Trapezius muscle

Sternomastoid muscle

clavicle

POSTERIOR TRIANGLE

Boundaries:- In front → Posterior border of sternomastoid m.- Behind → Anterior border of trapezius m.- Apex → Middle ⅓ of superior nuchal line.- Base → Middle ⅓ of the clavicle.Roof- Skin.- Superficial fascia.- Deep (investing) fascia of the neck.The superficial fascia of the posterior triangle contains the following :(1) Platysma m. : (a subcutaneous m.)(2) External Jugular vein (3)The cutaneous branches of the cervical plexusFloor: From below upwards:a) Scalenus medius. b) Levator scapulae. c) Splenius capitis.

Contents:

Arteries 1- Third part of subclavian a. 2- Suprascapular a.3- Superficial (or transverse) cervical a.4- Occipital a. (near the apex).Veins 5- Subclavian v., receiving its only tributary, the external jugular

v.Nerves 6- Roots and trunks of brachial plexus.7- Spinal accessory n. (runs on levator scapulae).L.Ns. 8- Occipital L.N. (at the apex with the occipital a.).9- Supraclavicular L.N. (at base with the subclavian a.).Ms. 10- Inferior belly of omohyoid .

OMOHYOID MUSCLE

DIVISION OF POSTERIOR TRIANGLE

Occipital triangle

Supra clavicular

ANTERIOR TRIANGLE

ANTERIOR TRIANGLE

□ Boundaries :• Anteriorly → Middle line of the neck.• Posteriorly → Ant. border of sternomastoid.• Base (above) → Lower border of mandible.• Apex (below) → Suprasternal notch.□ Roof:1- Skin.2- Superficial fascia (+ its contents).3- Investing ( deep ) fascia.Contents of the Superficial Fascia of the Roof:a- Platysma muscle.b- Transverse cervical n.c- Anterior jugular v. : It is formed by the union of the submental veins →

descendsin the superficial fascia near the middle line → pierces the deep fascia above thesternum → passes deep to the sternomastoid → ends in the external jugular v.

Thedeep parts of both anterior jugular veins are connected together by jugular

arch.□ Subdivisions : 3 ½ triangles . See the table .

DIGASTRIC MUSCLE

Suddivisions of

ANTERIOR TRIANGLE

Suprahyoid muscles

1-MYLOHYOID MUSCLE

Mylohyoid line

2- stylohyoid muscles 3- geniohyoid

Inferior mental spine

The suprahyoid muscles

the muscles of the floor of the mouth

Recall of relevant structures

Infrahyoid muscles

Important topics

Enumerate main contents of submandibular triangule and give short account on one of

them

1. Muscles: suprahyoid muscles

(mylohyoid muscle), geniohyoid, stylohyoid, digastric and hyoglossus muscles

2. Glands: submandibular salivary glands & L.N.

3. Nerves: nerve to mylo-hyoid muscle, hypoglossal nerves and Submandibular ganglion

4. Vessels: facial artery& vein

Enumerate main contents of submandibular region and give short

account on one of them

1. Muscles: 1:suprahyoid muscles

(mylohyoid muscle), geniohyoid, stylohyoid, digastric and hyoglossus muscles

2:genioglossus2. Glands: submandibular salivary glands & L.N.Sublingual salivary gland3. Nerves: nerve to mylo-hyoid muscle,

hypoglossal nerves and Submandibular ganglionLingual nerve4. Vessels: lingual & facial vessels

Facial vessels

Submandibular ganglionLingual

nerve

Sublingual salivary gland

Hypoglossal nerve

Lingual vessels

Nerve to mylohyoid muscle

Submandibular salivary gland

Muscle Origine Insertion Nerve supply action

Digastric muscle post. belly: Mastoid process of temporal bone ant. belly: Body of mandible

Intermediate tendon is held to hyoid by fascial sling

post. belly: facial nerveant belly: nerve to mylohyoid

Depresses mandible or elevates hyoid bone

Mylohyoid muscle Mylohyoid line of body of mandible

Body of hyoid bone and fibrous raphe

Inferior alveolar nerve

Elevates floor of mouth and hyoid bone or depresses mandible

Hyoglossus muscle Hyoid bone Post. ½ of the side of the tongue

Hypoglossal nerve Draw the tongue downwards and help suckling

Geniohyoid Genial tubercle of the mandible

Body of hyoid bone Hypoglossal nerve Depresses mandible or elevates hyoid bone

Styloyoid Styloid process Hyoid bone Facial nerve with post. Belly of digastric

Elevate hyoid bone

suprahyoid muscles

Enumerate main contents of carotid triangule and give short account on one of

them

1. Carotid sheath: CCA, ICA, IJV and vagus nerve

2. External carotid artery3. Hypoglossal nerve4. Ansa cervicalis5. Accessory nerve6. Sympathetic trunk

ANSA CERVICALIS

• It is a nervous loop situated in front of the carotid sheath.

• It is formed by union of 2 limbs :A) Superior limb : Descending from the

hypoglossal n. and containing fibers of C1 spinal nerve .

B) Inferior limb : From C2 and C3 spinal nerves .• Branches : arise from the tip → supply all

infrahyoid muscles (near their lower ends) except thyrohyoid.

Enumerate main contents of muscular triangule and give short account on one of

them Infra hyoid muscles

Enumerate main contents of submental triangule and give short account on one of

them

1. Submental LN2. Anterior jugular vein