Anterior neck (Thyroid and Strap Muscles) Flashcards
Hyoid bone: structure and function
- Greater and lesser horn and body
- Anchoring structure for the tongue
Suprahyoid muscles and function
- Forms the floor of the mouth
- Important role in mastication, swallowing and speech
- Positioning of hyoid bone
- Mylohyoid
- Geniohyoid
- Digastric
- Stylohyoid
Mylohyoid attachment and innervation
- Mandible and hyoid bone
- Pharyngeal muscle
- V3
Geniohyoid attachment and innervation
- Inferior mental spine of mandible and hyoid bone
- C1 via CNXII
Digastric attachment and innervation
- Mastoid, hyoid and mandible
- Pharyngeal muscle
- Anterior: CN V
- Posterior: CN VII
Stylohyoid attachment and innervation
- Styloid process and hyoid bone
- Pharyngeal muscle
- CN VII
Infrahyoid muscles and function
- Depress hyoid bone and larynx during speech and swallowing
- Sternohyoid
- Sternothyroid
- Thyrohyoid
- Omohyoid
Sternohyoid attachment and innervation
- Manubrium and hyoid
- C1-3 (ansa cervicalis)
Sternothyroid attachment and innervation
- Thyroid cartilage and manubrium (deeper than sternohyoid)
- C1-3
Thyrohyoid attachment and innervation
- Thyroid cartilage and hyoid bone
- C1 via hypoglossal
Omohyoid attachment and innervation
- Scapula, clavicle (intermediate tendon) and hyoid bone
- C1-3
Hyoglossus
- Hyoid, side of tongue
- Depresses, retracts tongue
Thyroid gland: structure and location
- Endocrine gland lies in visceral compartment of the neck between C5-T1
- Left and right lobes connected by isthmus
Thyroid gland: development
- Forms in the floor of primitive pharynx, near the base of tongue and descends
- Attached to trachea so ascends during swallowing
Thyroid gland: arterial supply
- Superior thyroid artery (first branch of ECA) (superior and anterior)
- Inferior thyroid anterior (thyrocervical/subclavian branch) (posteroinferior)
Thyroid gland: venous drainage
- Superior and middle thyroid veins drain to IJV
- Inferior vein drains to brachiocephalic vein
Thyroid gland: Innervation
- Sympathetic trunk
- Endocrine secretion controlled by pituitary gland
Thyroid gland: Lymphatic drainage
- Peri-thyroid nodes to:
- Prelaryngeal
- Pretracheal
- Paratracheal - Superior and inferior deep cervical nodes
Thyroid gland: Anatomical relations
- Strap muscles (infrahyoid) and sternocleidomastoid [anterolateral]
- Carotid sheath [posterolateral]
- Visceral compartment and recurrent/external laryngeal nerve [posteromedial]
- Parathyroid gland [posterior]
