Anterior triangle Flashcards
Describe the borders, roof and floor of the anterior triangle
Anterior border of the SCM,
inferior border of the mandible,
Midline of the neck
Roof = investing fascia
Floor = pretrcheal fascia and carotid sheath
Name the sub triangles of the anterior triangle
Carotid triangle
Submandibular triangle
Muscular triangle
Submental triangle
What are the suprahyoid muscles and their basic function?
Muscles superior to the hyoid bone
Mylohyoid and digastric muscle
Work to elevate the hyoid bone and the larynx and contribute substance to the floor of the mouth.
Describe the origin, insertion, innervation and action of the Mylohyoid muscle
Origin = mylohyoid line of mandible
Insertion = midline raphe and body of the hyoid bone
Innervation = mylohyoid nerve (branch of IAN of mandibular division of the trigeminal nerve)
Actions = elevate and draw forward hyoid bone, elevate tongue, depress mandible
Describe the origin, insertion, innervation and action of the posterior belly of the Digastric muscle
Origin = mastoid notch
Insertion = intermediate tendon of minor Cornu of hyoid bone
Innervation = facial nerve (CN VII)
Actions = elevate hyoid, depress mandible
Describe the origin, insertion, innervation and action of the anterior belly of the digastric muscle
Origin = digastric fossa of the mandible
Insertion = intermediate tendon of the minor Cornu of hyoid bone
Innervation = mylohyoid nerve
Actions = elevate hyoid and depress mandible
What are the infrahyoid muscles and their basic function?
Muscles inferior to hyoid bone
Sternohyoid, omohyoid, sternothyroid, thyrohyoid
Function to depress/fix the hyoid bone and to provide attachment for suprahyoid muscles
Describe the origin, insertion, innervation and action of the Sternohyoid
Origin = posterior of manubrium and sternal head of clavicle
Insertion = lower border of hyoid bone
Innervation = superior root ansa cervicalis
Actions = depress hyoid bone and pharynx for swallowing and phonation
Describe the origin, insertion, innervation and action of the Superior belly of the omohyoid
Origin = intermediate tendon
Insertion = lower border of the hyoid bone lateral to Sternohyoid
Innervation = superior root ansa cervicalis
Actions = depress/fix hyoid bone - swallowing and phonation
Describe the origin, insertion, innervation and action of the Inferior belly of the omohyoid
Origin = upper border of scapula, medial to scapula notch
Insertion = intermediate tendon
Innervation = inferior root ansa cervicalis
Actions = depress/fix hyoid bone - swallowing and phonation
Describe the origin, insertion, innervation and action of the Sternothyroid
Origin = posterior manubrium below sternothyroid
Insertion = oblique line of thyroid cartilage
Innervation = superior root ansa cervicalis
Actions = depress larynx
Describe the origin, insertion, innervation and action of the Thyrohyoid
Origin = oblique line of thyroid cartilage
Insertion = lower border of hyoid bone
Innervation = hypoglossal nerve, anterior rami of c1
Actions = depress hyoid bone and elevate larynx.
Describe the general form, position, and neuromuscular supply of the thyroid gland
2 lobes, right and left, that extend from the thyroid cartilage above to the 5th tracheal ring below.
Has a midline isthmus and a midline pyramidal lobe (not always present)
Situated within the pertracheal fascia
Innervation by the vagus nerve cervical ganglia.
Describe the general form, position and neuromuscular supply of the parathyroid gland
Parathyroid glands (4) sit on the deep posterior surface of the thyroid gland. 2 superior 2 inferior, 2 on each lobe.
They are innervation by thyroid branches of cervical ganglia from vagus nerve
Describe the structures of importance in an emergency airway situation, and basically the two types of emergency airway procedures
