Neck and Facial Muscles Flashcards
(47 cards)
Sternocleidomastoid
thick, cordlike muscle that extends from the sternum and clavicle ot the mastoid process posterior to the ear

What is the origin of the sternocleidomastoid?
manubrium of sternum, clavicle

What is the insertion of the sternocleidomastoid?
mastoid process

What is the action of the sternocleidomastoid?
singly, rotates head to opposite shoulder; together, flexes head
Sternohyoid
extends from the sternum to the hyoid, where it depresses the hyoid bone

What is the origin of the sternohyoid?
manubrium and clavicle

What is the insertion of the sternohyoid?
hyoid bone

What is the action of the sternohyoid?
depresses hyoid
Sternothyroid
located deep to the sternohyoid and extends from the sternum to the thyroid cartilage of the larynx

What is the origin of the sternothyroid?
manubrium

What is the insertion of the sternothryroid?
thyroid cartilage

What is the action of the sternothyroid?
depresses thyroid cartilage (of larynx)
Thyrohyoid
extends from the thyroid cartilage of hte larynx to the hyoid; closes off the larynx when swallowing

What is the origin of thyrohyoid?
thyroid cartilage

What is the insertion of thyrohyoid?
hyoid bone

What is the action of thyrohyoid?
depresses hyoid and elevates larynx
Mylohyoid
broad, flat muscle that proveds a musclular floor to the mouth; muscle fibers of the left and right are aligned in a V shape

What is the origin of mylohyoid?
mandible

What is the insertion of mylohyoid?
hyoid

What is the action of mylohyoid?
elevates hyoid
Digastric “two bellies”
two bellies. anterior and posterior; one belly extends from the mental protuberance of the hyoid, and the other continues from the hyoid to the mastoid portion of hte temporal bone
two bellies are united by an intermediate tendon that is held in position by a fascia sling (fibrous loop)

What is the origin of the digastric?
mandible and mastoid process

What is the insertion of the digastric?
by a connective tissue loop to hyoid bone

What is the action of the digastric?
depresses mandible; elevates hyoid bone









