Trunk muscles :)

MuscleDefinitionActionBony Attachment

Frontal Belly of Occipitofrontalis

Muscle of the forehead, part of the occipitofrontalis.

Elevates eyebrows, wrinkles forehead.

Galea aponeurotica; skin of forehead.

Occipital Belly of Occipitofrontalis

Muscle at the back of the head, part of the occipitofrontalis.

Pulls scalp posteriorly.

Occipital bone; mastoid process of temporal bone.

Orbicularis Oculi

Circular muscle around the eye.

Closes eyelids; helps in blinking.

Frontal bone; maxilla; medial palpebral ligament.

Orbicularis Oris

Circular muscle around the mouth.

Closes and protrudes lips.

Maxilla; mandible; skin around lips.

Zygomaticus Major

Muscle extending from the zygomatic bone to the corners of the mouth.

Elevates corners of the mouth (smiling).

Zygomatic bone; skin and muscle at corner of mouth.

Depressor Anguli Oris

Muscle that runs from the mandible to the corner of the mouth.

Depresses corners of the mouth (frowning).

Mandible; skin at the angle of the mouth.

Buccinator

Thin muscle in the cheek area.

Compresses cheek (whistling, sucking).

Maxilla; mandible; orbicularis oris.

Platysma

Thin sheet-like muscle in the neck.

Tenses skin of the neck; depresses mandible.

Skin over lower neck; pectoral and deltoid fascia.

Temporalis

Muscle located on the side of the skull.

Elevates and retracts mandible.

Temporal fossa; coronoid process of mandible.

Masseter

Thick muscle at the angle of the jaw.

Elevates mandible (chewing).

Zygomatic arch; ramus of mandible.

Medial Pterygoid

Muscle located inside the jaw.

Elevates and protrudes mandible.

Medial surface of pterygoid plate; ramus of mandible.

Lateral Pterygoid

Muscle located on the outside of the jaw.

Protrudes and moves mandible side to side.

Greater wing of sphenoid; neck of mandible.

Genioglossus

Muscle of the tongue, originating from the mandible.

Protrudes the tongue.

Mental spines of mandible; body of the tongue.

Hyoglossus

Muscle of the tongue, originating from the hyoid bone.

Depresses the tongue.

Body and greater horn of hyoid; side of tongue.

Styloglossus

Muscle of the tongue, originating from the styloid process.

Elevates and retracts the tongue.

Styloid process of temporal bone; side of tongue.

Suprahyoid Muscles

Group of muscles above the hyoid bone.

Elevates hyoid during swallowing.

Varies: mandible and temporal bone.

Infrahyoid Muscles

Group of muscles below the hyoid bone.

Depresses hyoid during swallowing.

Varies: sternum and thyroid cartilage.

Sternocleidomastoid

Muscle that runs from the sternum and clavicle to the mastoid process.

Rotates and flexes the neck.

Manubrium of sternum; medial portion of clavicle; mastoid process of temporal bone.

Splenius Capitis

Muscle at the back of the neck.

Extends and rotates the head.

Spinous processes of cervical and upper thoracic vertebrae; mastoid process; occipital bone.

Quadratus Lumborum

Muscle in the lower back.

Laterally flexes the spine; stabilizes pelvis.

Iliac crest; lower ribs; transverse processes of lumbar vertebrae.

Erector Spinae

Group of muscles along the vertebral column.

Extends and laterally flexes the spine.

Iliac crest; sacrum; spinous processes of vertebrae.

Diaphragm

Dome-shaped muscle separating thoracic and abdominal cavities.

Main muscle of respiration.

Xiphoid process; lower ribs; lumbar vertebrae.

External Intercostals

Muscles between the ribs, running diagonally.

Elevates ribs during inhalation.

Inferior border of ribs; superior border of ribs below.

Internal Intercostals

Muscles between the ribs, running horizontally.

Depresses ribs during forced exhalation.

Superior border of ribs; inferior border of ribs above.

External Oblique

Superficial abdominal muscle.

Flexes and rotates the trunk.

Lower ribs; iliac crest; linea alba.

Internal Oblique

Intermediate abdominal muscle.

Flexes and rotates the trunk.

Iliac crest; inguinal ligament; lower ribs; linea alba.

Transversus Abdominis

Deepest abdominal muscle.

Compresses abdominal contents.

Iliac crest; lower ribs; linea alba; thoracolumbar fascia.

Rectus Abdominis

Vertical abdominal muscle.

Flexes the vertebral column.

Pubic symphysis; pubic crest; costal cartilages of ribs 5-7.