N3 Anatomy and Physiology (1st Sem AY 2022-2023)

ITEM

MUSCLE

ORIGIN

INSERTION

ACTION

1

Platysma

Fascia over the deltoid and pectoralis major muscles

Mandible, blends with muscles around the angle of the mouth, and skin of the lower face

• Draws outer part of lower lip inferiorly and posteriorly
• Depresses mandible

2

Mentalis

Mandible

Skin of chin

• Elevates and protrudes lower lips
• Pulls the skin of chin up

3

Orbicularis oris

Muscle fibers surrounding the opening of the mouth

The skin at the corner of the mouth

• Closes and protrudes lips
• Compresses lips against teeth
• Shapes the lips during speech

4

Corrugator supercilii

The medial end of the superciliary arch of the frontal lobe

Skin of eyebrow

• Draws eyebrows inferiorly
• Wrinkles the skin of the forehead vertically

5

Orbicularis oculi

The medial wall of the orbit

Circular path around the orbit

• Closes eye

6

Occipitofrontalis (frontal belly)

Epicranial aponeurosis

Skin superior to supraorbital margin

• Draws scalp anteriorly
• Raises eyebrows
• Wrinkles skin of forehead horizontally