ACTIVITY 1

DELA CRUZ, Rhana Shana_Activity 1

DELA CRUZ, Rhana Shana_Activity 1

by Rhana Shana Dela Cruz -
Number of replies: 0

Name the muscle that may cause the following facial expression and write down its origin, insertion and action.

 

1. PLATYSMA

Origin: fascia of the upper thorax (including the clavicle, acromial region, pectoralis major, and deltoid muscle)

Insertion: lower border of mandible, skin of buccal/cheek region, lower lip, modiolus, orbicularis oris, and in some cases, orbicularis oculi 

Action: depresses mandible and angle of mouth, tenses skin of lower face and anterior neck 

 

2. MENTALIS

Origin: incisive fossa of mandible

Insertion: skin of chin/mentolabial sulcus

Action: elevates, everts, and protrudes lower lip, wrinkles skin of chin 

 3. ORBICULARIS ORIS

Origin: medial aspects of maxilla and mandible, perioral skin and muscles, modiolus

Insertion: skin and mucous membrane of lips

Action: closes mouth, compresses and protrudes lips 

 

4. CORRUGATOR SUPERCILII

Origin: medial end of superciliary arches, fibers of orbicularis oculi muscle 

Insertion: skin above middle of supraorbital margin

Action: pull the eyebrows medially and inferiorly

 

5. ORBICULARIS OCULI

Origin: nasal part of frontal bone, frontal process of maxilla, medial palpebral ligament, lacrimal bone 

Insertion: skin of orbital region, lateral palpebral raphe, superior and inferior tarsal plates 

Action: closes eyelids tightly (orbital part), closes eyelids gently (palpebral part), compresses lacrimal sac (deep palpebral part)

 

 6. OCCIPITOFRONTALIS

Origin: frontal belly (frontalis), skin of eyebrow, muscles of forehead

Insertion: epicranial aponeurosis

Action: elevates eyebrows, wrinkles skin of forehead (frontal belly), retracts scalp (occipital belly)