(II) Musculoskeletal Systems 🧠

Occipitofrontalis

Origin: superior nuchal line (occipital bone).

Insertion: epicranial aponeurosis.

Action: moves the scalp posteriorly.

temporalis

Origin: Temporal bone

Insertion: coronoid process of the mandible

Action: Closes Jaw

orbicularis oculi

Origin: Maxilla

Insertion: Tissues of eyelids

Action: Closes eyelids/wink/blink

orbicularis oris

Origin: Maxilla and Mandible

Insertion: Skin of the lips

Action: opening and closing lips

Zygomaticus Major

Origin: Zygomatic Bone

Insertion: Skin and muscle at the corner of the mouth

Action: Smile! (raises the lateral corners of the mouth)

buccinator

Origin: Molar region of Maxilla and mandible

Insertion: Orbicularis oris

Action: Compresses cheek (whistling and sucking)

(Unlikely)

masseter

Origin: zygomatic bone

Insertion: mandible

Action: Closes jaw

mentalis

Origin: Mandible

Insertion: Skin of the chin

Action: Wrinkles chin

depressor anguli oris

Origin: Mandible

Insertion: Skin and muscle at the angle of the mouth

Action: frowning

Platysma

Name this Muscle (P)

Styloglossus

Origin: Styloid process of the temporal bone

Insertion: Inferior portion of the tongue

Action: Retract and elevate the tongue

Hyoglossus

Origin: body and greater horn of the hyoid bone

Insertion: Inferolateral tongue

Action: Depresses tongue

genioglossus

Origin: Internal surface of the mandible

Insertion: Inferior tongue and hyoid bone;

Action: Protracts the tongue

Geniohyoid

Origin: Mandibular symphysis (inner surface)

Insertion: Hyoid bone

Action: Elevates and protracts the Hyoid bone

Thyrohyoid

Origin: Thyroid cartilage

Insertion: Hyoid bone

Action:Depresses hyoid bone

Stylohyoid

Origin: Styloid process

Insertion: Hyoid Bone

Action: Elevates and retracts the hyoid bone

Mylohyoid

Origin: Medial surface of the mandible

Insertion: Hyoid bone and median raphe

Action: Elevates hyoid bone

Digastric

Origin: Lower margin of the mandible (Ab) and mastoid process (Pb)

Insertion: Connective tissue loop near the hyoid bone

Action: Elevates the hyoid bone

Omohyoid

Origin: Scapula;

Insertion: Hyoid bone;

Action: Depresses the hyoid bone

Sternocleidomastoid

Origin: Manubrium and clavicle

Insertion: Mastoid process

Action: Flexes head

Sternohyoid

Origin: Sternum;

Insertion: Hyoid bone;

Action: Depresses the hyoid bone

Sternothyroid

Origin: Manubrium

Insertion: Thyroid cartilage

Action: Depresses larynx and hyoid

Scalenes

Origin: Transverse processes of cervical vertebrae

Insertion: First two ribs

Action: Elevates first two ribs

Erector spinae

They include the iliocostalis, longissimus and spinalis muscles.

Action: Extension of head neck and trunk

Quadratus lumborum

Identify this muscle (QL)

Rectus abdominis

Identify this Muscle (RA)

External oblique

Identify this Muscle (EO)

Internal oblique

Identify this Muscle (IO)

transverse abdominis

Identify this muscle (TA)

Diaphragm

Origin: Xiphoid process

Insertion: Central tendon.

Action: Flattening the diaphragm

intercostals

Helps us breathing in or out

Subclavius

Muscle under the clavicle

Serratus anterior

Origin: ribs 1-8

Insertion: Scapula

Action: Rotates scapula upward.

Trapezius

Origin: Midline Origin

Insertion: Scapula and Clavicle

Action: elevation, adduction, rotation, and stabilization

Levator scapulae

Origin: Transverse processes of cervical vertebrae

Insertion: Medial border of the scapula

Action: Elevates and adducts scapula

Rhomboids

Origin: Spinous processes of cervical and thoracic vertebrae

Insertion: Medial border of the scapula.

Action: Adduction of the Scapula

Pectoralis major

Origin: Clavicle

Insertion: Humerus

Action: Prime mover of arm flexion

Supraspinatus

Origin: Supraspinous fossa of scapula.

Insertion: Greater tubercle of humerus.

Action: Abducts humerus

Infraspinatus

Origin: Infraspinous fossa of scapula.

Insertion: Greater tubercle of humerus.

Action: Laterally rotates the arm

Teres minor

Origin: Lateral border of scapula.

Insertion: Greater tubercle of humerus.

Action: Laterally rotates the arm

Teres major

Origin: Inferior angle of scapula.

Insertion: Intertubercular sulcus of humerus.

Action: medial rotation the humerus.

Latissimus dorsi

Origin: Thoracic, and Lumbar Fascia

Insertion: Humerus

Action: Prime mover of arm extension

Subscapularis

Origin: Subscapular fossa

Insertion: lesser tubercle

Action: Medial rotation

Psoas major

Origin: Lumbar vertebrae

Insertion: Lesser Trochanter

Action: Thigh flexion and flexing trunk

Iliacus

Origin: Iliac fossa

Insertion: Lesser trochanter

Action: Thigh flexion and flexing trunk (bowing)