BIOL 319 muscles and actions lab 4

Obliques (external and internal)

Compression of abdomen, flexion, and rotation of trunk

Transverse abdominis

Compression of abdomen

Rectus abdominis

Flexion of trunk; compression of abdominal wall

Intercostals (external and internal)

Elevation and depression of ribs

Diaphragm

Opens thoracic cavity for lungs during inspiration

Frontalis

Raises eyebrows

Occipitalis

Pulls scalp posteriorly

Temporalis

Closes jaw; retracts mandible

Masseter

Closes jaw

Zygomaticus

Elevates corners of mouth

Buccinator

Compression of cheek

Platysma

Tenses skin of neck; depression of lower lip

Orbicularis oculi

Closes eyes

Orbicularis oris

Closes and protrudes lips

Levator labii superioris

Elevation of upper lip

Depressor labii inferioris

Depression of lower lip

Sternocleidomastoid

Flexion and rotation of neck

Scalenes

Elevation of ribs 1 & 2; rotation of neck

Serratus anterior

Abduction and rotation of scapula

Rhomboids

Adduction and elevation of scapula

Splenius

Rotation of head; extension of neck

Digastric

Elevation of hyoid; opens mouth

Mylohyoid

Elevation of hyoid and floor of mouth

Geniohyoid

Elevation and protraction of hyoid bone

Sternohyoid

Depression of hyoid and larynx

Sternothyroid

Depression of hyoid and larynx

Thyrohyoid

Depression of hyoid; elevation of larynx