1. Necks

2. Triangles of the Neck Anterior Triangle Mandible Posterior Triangle
Median Plane
Triangles
Posterior Triangle borders (review)
Posterior: Trapezius
Anterior: Sternocleidomastoid
Inferior: Clavicle
Anterior Triangle Borders:
Lateral:
Superior:
Medial:
Sternocleidomastoid

3. Omohyoid (superior belly)
Muscular Triangle
Contents:
Infrahyoid mm
Cricothryoid m
Thyroid gland
Parathyroid gland
Omohyoid (superior belly)
Median plane
Muscular Triangle
Borders:
Superolateral:
Inferolateral:
Medial:
Contents:
Muscles
Glands
Sternocleidomastoid

4. Hyoid Bone Hyoid bone “Hyoid” Boney articulations?
Vertebral position of hyoid:
Greater horns
Lesser horns
Strangling

5. Cartilages Thyroid Cartilage Cricoid Cartilage Thyrohyoid membrane
Cricothyroid ligament
Cricothyroid ligament
Cartilages
Thyroid cartilage
“Thyroid”
Laryngeal prominence
Oblique line
Thyrohyoid membrane
Superior horns
Inferior horn
Cricoid cartilage
“Cricoid”
Arch
Cricothyroid Membrane (or Ligament)
Superior Horn
Laryngeal Prominence
Inferior Horn
Oblique line
Cricoid Cartilage
Thyroid Cartilage

6. Infrahyoid “Strap” Muscles Superficial Layer
Omohyoid
Superior Belly
Inferior Belly
Sternohyoid
Omohyoid
Sternohyoid
Infrahyoid Muscles (Superficial)
Omohyoid
O: Scapula- just medial to scapular notch
I: Lower border of hyoid
Intermediate tendon
Fascial sling attached to:
Sternohyoid
O: Deep side of manubrium and SC joint
I: Lower border of hyoid bone
Fascial sling of omohyoid

7. Infrahyoid “Strap” Muscles Deep Layer
Sternothyroid
Thyrohyoid
Thyrohyoid
Sternohyoid
Sternothyroid
Omohyoid
Infrahyoid Muscles (deep)
Sternothyroid
O: Deep side of manubrium
I: Oblique line of thyroid cartilage
Thyrohyoid
O: Oblique line of thyroid cartilage
I: Lower border of hyoid bone
Collective Function (of all 4):
Exception:
Common Innervation:

8. Cricothyroid Muscle External Laryngeal N. Cricothyroid Cricothyroid
O: Arch of cricoid cartilage
I: Lamina of thyroid cartilage
Fxn:
Inn:
Cricothyroid

9. Thyroid Gland Variation Vasculature Pyramidal lobe Superior Thyroid A
Inferior Thyroid A
Thyroid Ima (occassionally)
Inferior Thyroid A
Thyroid Gland
Lobes
Isthmus
Location
Pyramidal Lobe
Blood Supply
Superior thyroid A
Branch of:
Inferior thyroid A
Thyroid ima

10. Thyroid: Clinical Considerations
Recurrent Laryngeal N
Parathyroid Glands
Considerations
Thyroid Ima A
Recurrent Laryngeal NN
Thyroid (cont)
Thyroid ima A
“Ima”
Branch of:
Relevance
Recurrent laryngeal NN
Location:
Supply:
Thyroid Ima A

11. Parathyroid Glands Recurrent Recurrent
Most common number:
Range:
Pharyngeal (Brancheal) Arch of superior parathyroid glands:
Same arch as:
Theoretical Location of superior parathyroid glands:
Pharyngeal (Brancheal) Arch of inferior parathyroid glands:
Theoretical Location of inferior parathyroid glands:
Common anomalous locations:
Parathyroid function
Recurrent
Recurrent
The Center for Advanced Head and Neck Surgery.

12. Suprahyoid Muscles Digastric Stylohyoid Mylohyoid Geniohyoid
Anterior Belly
Posterior Belly
Stylohyoid
Mylohyoid
Geniohyoid
Digastric (post)
Digastric (ant)
Suprahyoid
Digastic
O: Digastric fossa of mandible
I: Mastoid notch
Intermediate tendon
Fascial sling attached to:
Innervation of anterior belly:
Innervation of posterior belly:
Additional Fxn (general fxn listed below):
Stylohyoid
O: Styloid process
I: Hyoid bone
Splits to go around:
Inn:
Mylohyoid
O: Mylohyoid line on mandible
Geniohyoid
Deep to:
O: Mental spines (aka genial tubercles) of mandible
General function of all: Elevate/Stabilize hyoid
Digastric (post)
Mylohyoid
Geniohyoid
Stylothyoid
Digastric (ant)

13. Carotid Triangle Contents: Digastric (posterior belly)
Common Carotid A.
Internal Carotid A.
External Carotid A.
Branches
Internal Jugular V.
Hypoglossal N.
Vagus N. (branches)
Parts of Cervical Plexus
Carotid triangle
Borders:
Lateral
Medial
Superior
Contents (see slide)
Omohyoid (superior belly)
Sternocleidomastoid

14. External Carotid Bifurcation Branches Superior Thyroid A. Lingual A.
Superior Laryngeal A.
Lingual A.
Facial A.
Ascending Pharyngeal A.
Occipital A.
Others:
Maxillary A.
Superficial Temporal A.
Posterior Auricular A.
Subclavian A.
Common Carotid A.
Superior Thyroid A.
Lingual A.
Occipital A.
Ascending Pharyngeal A.
Facial A.
Carotid arteries
Common Carotid origin:
‘Carotid’
Approximate location of common carotid bifurcation:
Internal Carotid A
Branches before entering skull?
External Carotid Branches
Superior Thyroid A
Superior Laryngeal A
Pierces:
Lingual A
Deep to:
Facial A
Common anomaly:
Ascending pharyngeal A
Occipital A
Off external carotid but not seen in neck:
Maxillary A
Superficial Temporal A
Posterior Auricular A

15. Sternocleidomastoid (cut)
Carotid Sheath
Carotid Sheath
Carotid Sheath
Internal Jugular V.
Vagus N.
Common Carotid A.
Then, Internal Carotid A
Investing Fascia
Pretracheal Fascia
Prevertebral Fascia
Carotid Sheath
Carotid Sheath
Carotid sheath
Inferior endpoint
Superior endpoint
Contents:
(1)
(2)
(3)
Sternocleidomastoid (cut)

16. Cervical Plexus VPR C1-C4 Phrenic nerve Cutaneous branches
* already seen in the posterior triangle
Muscular branches
Cervical Plexus
Anterior or posterior primary rami?
Spinal cord levels:
Phrenic nerve
Cord levels:
Location (in cervical region):
Cutaneous Branches discussed last time:
Lesser Occipital N (C2)
Great Auricular N (C2,3)
Transverse Cervical N (C2,3)
Supraclavicular NN (C3,4)
Muscular branches (Ansa Cervicalis)
Fig 8.11 Clinically Oriented Anatomy 5th Ed. Moore & Dalley

17. Cervical Plexus: Muscular Branches
Hypoglossal N (CN XII)
VPR C1
Nerve to Thyrohyoid
Superior root of Ansa Cervicalis
Inferior root of Ansa Cervicalis
Phrenic N C2 C3 .
Ansa cervicalis
Superior root (C1)
Inferior root (C2,3)
N. to thyrohyoid
Cervical Plexus (Muscular)
Ansa cervicalis
Supplies:
Superior root:
Inferior root:
‘Ansa’
Hypoglossal nerve
Superior root of ansa cervicalis
Nerve to thyrohyoid

18. Cervical Plexus: Muscular Branches
Phrenic N
Unnamed nerves
prevertebral mm.
N. to thyrohyoid
Ansa cervicalis
Superior root
Inferior root
Spatial context of ansa cervicalis
Relation of superior root to carotid sheath:
Relation of inferior root to carotid sheath:
Contents of carotid sheath:
Fig 7.8, Grant’s Dissector 14th Ed.

19. Submandibular Triangle
Mandible
Contents:
Submandibular gland
Facial A. & V.
Stylohyoid M.
Lymph Nodes
Hypoglossal N (portion)
Digastric
(Post. Belly)
Submandibular triangle
Borders:
Superior
Posteroinferior
Anteroinferior
Contents (see slide)
Digastric
(Ant. Belly)

20. Hypoglossal Nerve (CNXII)
Hypoglossal N (CN XII)
Hypoglossal nerve
Origin: medulla oblongata
Exits skull:
VPR C1
Supplies:
Exception:
Functional component(s) of Hypoglossal:

21. Digastric (Ant. Bellies)
Submental Triangle
Digastric (Ant. Bellies)
Contents:
Submental Lymph Nodes
Hyoid
Submental triangle
“Mental”
Borders:
Inferior
Superolateral (both sides)
Contents: