The neck is the region between the head and trunk that contains important structures. It functions to transport the esophagus, trachea, blood vessels, and nerves between the head and chest. The boundaries of the neck include the mandible superiorly, the clavicles inferiorly, and vertebrae posteriorly. The surface anatomy includes palpable structures like the thyroid cartilage. The neck is divided into the anterior and posterior triangles by the sternocleidomastoid muscle. The anterior triangle contains structures like the carotid artery and jugular vein.

1. The Neck
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2. • is relatively narrow and flexible portion between
the head above and the chest below
• Functions:
1. transports a food tube, an air tube, and a
neurovascular bundle between the head and chest.
2. the upper limbs originate from the cervical
region during their embryological development,
3. passageway for the blood vessels and nerves to
and from the upper limb.
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3. BOUNDARIES OF THE NECK
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4. A. Superior
1. Anterior
- lower border of the mandible
2. Lateral
- line between the gonion and the mastoid temporal,
3. Posterior
- inion and superior nuchal line
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5. B. Inferior
1. Anterior -
jugular or suprasternal notch
2. Lateral -
superior border of the clavicle,
3. Posterior-
transverse line from the acromioclavicular joint to the spinous process
of the 7th cervical vertebra
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6. SURFACE ANATOMY OF THE NECK
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7. Contour
• well-rounded in women and children and is
more angular in men
• natural upright position of the neck is midway
between flexion and extension
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8. Structures Palpated in the Midline
 body of the hyoid
bone
 thyroid cartilage
 cricoid cartilage
 Trachea
 isthmus of the thyroid
gland
 suprasternal notch
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9. Structures Palpated Posteriorly
 Inion
 Nuchal goove
 Vertebra prominence
 Ligamentum nuchae
which covers spines
of C2 to C6
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10. Structures Palpated Laterally
 Sternocleido-mastoid
muscle
 Trapezius muscle
 External jugular veins
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11. The Muscles and Triangles of the
Neck
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12. Regions of the Neck
 To facilitate the seemingly complicated area, the neck
is divided into two major areas, or triangles, by the
sternocleidomastoid muscle.
 These are:
1. anterior triangle
- the area anterior to the SCM and below the
inferior border of the mandible
2. posterior triangle
- the area posterior to the SCM and is
limited posteriorly by the trapezius muscle
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14. Sternocleidomastoid Muscle
Origin Insertion Action Nerve
Supply
Two heads: Mastoid process Bilateral: 1. Spinal
Sternal head – of the of the Flex the neck accesory nerve
manubrium temporal bone 2. Anterior
sterni and lateral half primary rami of
of the superior Single:
spinal nerves C2
nuchal line. Flex the head and C3.
Clavicular head and laterally
- Medial 2/3 of rotate to the
the clavicle opposite side
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15. Trapezius Muscle
Origin Insertion Action Nerve
Supply
External Fibers Contract to 1. Spinal
occipital originating from rotate and accessory nerve
protruberance, the head insert elevate the
the medial half into the lateral scapula. Its 2. Anterior
of the superior third of the cervical portion, primary rami of
nuchal line, the clavicle, and the acting the spinal
ligamentum remaining fibers bilaterally, can nerves C3 and
nuchae, and the insert into the extend the head C4.
lower cervical acromion and singly, it
and all the process and can rotate the
thoracic spines spine of the head and face
scapula to the opposite
side 15

16. The Anterior Triangle
of the Neck
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17. MUSCLES OF THE
ANTERIOR TRIANGLE OF THE NECK
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18. I. Infrahyoid Muscles
Muscle Origin Insertion Action Nerve
Supply
Omohyoid Inferior belly: Inferior belly: Depresses the Ansa
Superior Intermediate hyoid bone cervicalis
border of the tendon and larynx (APR of C1,
scapula Superior C2, C3)
Superior belly:
belly: Lower border
Intermediate of the body of
tendon the hyoid
bone
Sternohyoid Manubrium of Lower border Depresses the Ansa
the sternum, of the body of hyoid bone cervicalis
posterior the hyoid and larynx (APR of C1,
aspect bone C2, C3)
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19. Infrahyoid Muscles
Muscle Origin Insertion Action Nerve
Supply
Sternothyroid Manubrium of Oblique line Depresses the Ansa
the sternum, of thyroid larynx cervicalis
posterior cartilage (APR of C1,
aspect C2, C3)
Thyrohyoid Oblique line of Body and Depresses the Thyrohyoid
thyroid greater horn hyoid bone branch of the
cartilage of hyoid bone, hypoglossal
lower border nerve
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20. II. Suprahyoid Muscles
Muscle Origin Insertion Action Nerve
Supply
Stylohyoid Styloid Greater horn Elevates Facial nerve
process of hyoid hyoid bone
bone
Digastric Digastric Intermediate Raises the Facial nerve
(Posterior notch of the tendon hyoid bone
belly) temporal bone
at the base of
the skull
Digastric Intermediate Digastric Elevates the Nerve to the
(anterior tendon fossa of the hyoid bone mylohyoid
belly) mandible muscle
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21. Suprahyoid Muscles
Muscle Origin Insertion Action Nerve
Supply
Mylohyoid Mylohyoid line Median raphe Elevates the Nerve to
on the medial and body of hyoid bone, mylohyoid
aspect of hyoid base of the muscle
mandibular tongue, and
body floor of the
mouth
Geniohyoid Inferior Body of hyoid Elevates hyoid APR of C1
muscle border genial bone bone,
tubercle of protracts
the mandible hyoid bone
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22. BOUNDARIES OF THE ANTERIOR
TRIANGLE
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23. • Anterior
- median line of the neck
• Posterior
– anterior border of the sternocleidomastoid muscle
• Superior
- inferior border of the mandible
• Roof
- skin, superficial fascia, platysma, and investing layer of deep cervical
fascia
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24. SUBDIVISIONS OF THE
ANTERIOR TRIANGLE
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25. 1. Digastric Triangle
2. Carotid triangle
3. Muscular or inferior carotid triangle
4. Submental triangle
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26. 1. Digastric Triangle
Boundaries:
1. Superior-
lower border of the mandible
2. Anterior –
anterior belly of the digastric
3. Posterior –
posterior belly of the digastric
4. Floor -
mylohoid and hyoglossus muscles and superior contrictor muscle of the pharynx
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27. Structures:
1. Glands
– parotid and submandibular
2. Arteries
- Internal and external carotid, facial, submental, posterior
auricular, superficial temporal and lingual.
3. Veins
- anterior facial and internal jugular.
4. Nerves
– vagus, glossopharyngeal, facial, and hypoglossal.
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28. 2. Carotid Triangle
Boundaries:
1. Superior
– posterior belly of the digastric
2. Inferior
– superior belly of omohyoid
3. Posterior
– anterior border of the SCM
4. Floor
- thyrohyoid muscle, hyoglossus muscle, and the middle and inferior constrictor
muscles of the pharynx.
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29. Structures:
1. Organs
– larynx and pharynx (lower part)
2. Arteries
- CCA, facial, occipital, acending pharyngeal, superior thyroid, and lingual.
3. Veins
- internal jugular, superior thyroid, lingual, facial, occipital and ascending
pharyngeal.
4. Nerves
- vagus, accessory, hypoglossal, ansa hypoglossi, external and internal laryngeal.
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30. 3. Muscular or Inferior
Carotid Triangle
Boundaries:
1. Supero-posterior
- superior belly of omohyoid
2. Infero-posterior
- anterior border of SCM
3. Anterior
- median line of the neck
4. Floor
- sternohyoid and sternothyroid
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31. Structures:
1. Organs
– thyroid and parathyroid glands, trachea
2. Arteries
- inferior thyroid
3. Veins
- internal jugular
4. Nerves
- vagus, recurrent laryngeal, sympathetic n.
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32. 4. Submental Triangle
Boundaries:
1. Lateral
- two anterior bellies of the digastric
2. Inferior
- body of the hyoid bone
Structures:
1. Submental lymph glands
2. Beginning of the anterior jugular vein
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33. The Posterior Triangle
of the Neck
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34. Boundaries:
1. Anterior
- posterior border of the SCM.
2. Posterior
- anterior border of the trapezius muscle.
3. Inferior
- superior border of the intermediate 1/3 of trhe clavicle.
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35. 4. Superior
- meeting of the trapezius and SCM at the superior nuchal
line.
5. Roof
- formed by the skin, superficial fascia, platysma and
investing layer of the deep cervical fascia.
6. Floor
- formed by several muscles – semispinalis capitis, splenius
capitis, levator scapulae, and scalene muscles
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36. Muscles of the
Posterior Triangle of the Neck
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37. Muscle Origin Insertion Action Nerve
Platysma Superficial Inferior Stretches Facial nerve
fascia of the border of tight the
deltoid and the skin of the
pectoral mandible, neck,
regions some fibers depresses
sweep the mandible
upward and
blend with
risorius
Splenius Lower part Mastoid Bilateral: Cervical
capitis of the process and Extends the spinal nerves
ligamentum the superior head
nuchae, nuchal line Individual:
lower
cervical Flexes the
spines head
laterally
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38. Muscle Origin Insertion Action Nerve
Levator Transverse Superior Elevates and Dorsal
scapulae processes of portion of rotates the scapular
C1 to C4 the vertebral scapula nerves
border of
the scapula
Scalenius Transverse Superior Flexes the APR of C5 to
posterior processes of aspect of the neck C8
C5 and C6 second rib
Scalenius Transverse Superior Flexes the APR of C3
Medius processes of aspect of the neck and C4
C2 to C7 first rib
Scalenius Transverse Scalene Participates APR of C5 to
anterior processes of tubercle of in forced C8
C3 to C6 the first rib inspiration
by elevating
the ribs and
sternum
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39. Subdivisions of the
Posterior Triangle
1. Occipital Triangle
2. Supraclavicular Triangle
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40. 1. Occipital Triangle
Boundaries:
1. Anterior
- posterior border of
SCM
2. Posterior
- anterior border of
the Trapezius M.
3. Superior
- meeting between
the trapezius and
SCM
4. Inferior
- superior border of
the inferior belly of
omohyoid
40

41. 2. Supraclavicular or Subclavian or
Omoclavicular Triangle
Boundaries:
1. Anterior
- posterior border of
SCM
2. Superior
- inferior border of
the inferior belly of
omohyoid
3. Inferior
- superior border of
the intermediate 1/3
of the clavicle
41

42. Contents of the Posterior Triangle
1. Arteries
- subclavian artery, transverse cervical artery, occipital artery and
suprascapular artery.
2. Veins
- external jugular vein, anterior jugular vein, transverse cervical
vein, suprascapular and subclavian veins.
3. Nerves
- spinal accessory nerve, cutaneous and muscular branches of the
cervical plexus, ansa cervicalis and root, trunk and divisions of the
brachial plelxus.
4. Lymph glands
- supraclavicular lymph glands, and the lateral superior deep cervical
lymph glands.
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