LAB 8

• FRONTALIS (forehead)

  A: raise eyebrows

  O: Epicranial aponeurosis

  I: Skin of eyebrows and root of nose

  **Muscle Group: Muscles of the scalp
• OCCIPITALIS

  A: pulls scalp posteriorly

  O: Occipital and temporal bones

  I: Epicranial aponeurosis

  **Muscle group: muscles of the scalp
• TEMPORALIS

  A: close jaw; elevates and retracts mandible

  O: temporal fossa

  I: coronoid process of mandible

  **Muscle group: Mastication
• MASSETER

  A: prime mover of jaw closure; elevates mandible

  O: zygomatic arch and zygomatic bone

  I: Angle and ramus of mandible

  **Muscle Group: mastification
• MEDIAL PTERYGOID

  A: acts with lateral pterygoid muscle to protrude mandible and promote side to side movement

  O: Medial surface of lateral plate of sphenoid bone; maxilla and palatine bone

  I: medial surface of mandible near its angle

  **muscle group: mastification
• LATERAL PTERYGOID

  A: provides forwards sliding and side to side grinding movements of lower teeth

  O: greater wing and lateral pterygoid plate of sphenoid bone

  I: Condyle of mandible and temporomandibular joint

  **Muscle group: mastication
• ZYGOMATICUS

  A: Raise lateral corners of mouth upwards

  O: zygomatic bone

  I: skin and muscle at corner of mouth

  **Muscle group: facial expression
• BUCCINATOR

  A: compresses cheek; draws corner of mouth laterally

  O: molar region of maxilla and mandible

  I: orbicularis oris

  **Muscle group: facial expression
• PLATYSMA

  A: Tenses skin of neck; depresses mandible

  O: fascia of chest

  I: lower margin of mandible; skin and muscle at corner of mouth

  **Muscle group: facial expression
• ORBICULARIS OCULI

  A: closes eye; produces blinking and squinting; draws eyebrows inferiorly

  O: frontal and maxillary bones; ligaments around orbit

  I: Tissue of eyelid

  **Muscle group: facial expression
• ORBICULARIS ORBIS

  A: closes lips; purses and protrudes lips

  O: Maxilla and mandible

  I: skin and muscle at angles of mouth

  **Muscle group: facial expression
• LEVATOR LABII SUPERIORIS

  A: opens lips; raises and furrows the upper lip

  O: zygomatic bone and infraorbital margin of maxilla

  I: skin and upper lip

  **Muscle group: facial expression
• DEPRESSOR LABII INFERIORIS

  A: draws lower lip inferiorly

  O: Body of mandible lateral to its midline

  I: Skin and muscle of lower lip

  **Muscle group: facial expression
• STERNOCLEIDOMASTOID

  A: flexes and laterally rotates head; neck flexion

  O: Manubrium of sternum; medial portion of clavicle

  I: Mastoid process of temporal bone; superior nuchal line of occipital bone

  **Muscle group: anterolateral neck
• SCALENES

  A: elevation of ribs 1&2; lateral flexion and rotation of neck

  O: transverse process of C3-7 vertebrae

  I: Ribs 1-3

  **Muscle grou: Anterolateral neck
• SERRATUS ANTERIOR

  A: abduction, medial rotation of/and stabilizes scapula (hold against thoracic wall)

  O: Ribs 1-8

  I: Medial border of scapula

  **Muscle group: Anterior thorax
• LEVATOR SCAPULAE

  A: elevates and adducts scapula

  O: transverse processes of C1-C4

  I: medial border of scapula, superior to the spine

  **Muscle group: posterior thorax
• RHOMBOIDS

  A: adduction and elevation of scapula

  O: Spinous processes of C7-T5 vertebrae

  I: Medial border of scapula

  **Muscle group: Posterior thorax
• SPLENIUS 

  A: rotation of head to same side; extension of head and neck

  O: Nuchal ligament spinous processes of C7, T1-T6 vertebrae

  I: temporal bone (mastoid process); occipital bone (superior nuchal line); transverse process of C1-C3 vertebrae

  **muscle group: intrinsic muscles of the back
• ILIOCOSTALIS

  A: Lateral flexion of vertebral column; extension of vertebral column; depression of ribs

  O: Iliac crest; ribs

  I: Ribs; transverse process of cervical vertebrae

  **Muscle group: Neck and vertebral column
• SEMISPINALIS CAPITIS

  A: rotation of head to opposite side; extension of head and neck

  O: transverse process of C7-T6 vertebrae

  I: Occipital bone

  **Muscle group: Neck and vertebral column
• LONG HEAD 

  A: forearm extension; stabilizes shoulder joint and assist in arm adduction

  O: infraglenoid tubercle of scapula

  I: common tendon into olecranon process of ulna

  **Muscle group: Posterior arm (of triceps brachii)
• LATERAL HEAD

  A: forearm extension

  O: posterior shaft of humerus

  I: common tendon into olecranon process of ulna

  **muscle group: posterior arm (of biceps brachii)
• MEDIAL HEAD

  A: forearm extension

  O: Posterior humeral shaft distal to radial groove

  I: Common tendon into olecranon process of ulna

  **muscle group: posterior arm (of biceps brachii)
• DIGASTRIC

  A: Opens mouth and depresses mandible; elevates hyoid bone and steadies it during speech and swallowing 

  O: Lowers margin of mandible; mastoid process of temporal bone

  I: hyoid bone

  **muscle group: anterior neck (supra hyoid)
• STYLOHYOID

  A: elevates and retracts hyoid during swallowing

  O: Styloid process of temporal bone

  I: Hyoid bone

  **muscle group: anterior neck (supra hyoid)
• MYLOHYOID

  A: elevates hyoid bone and floor of mouth

  O: Medial surface of mandible

  I: Hyoid bone and median raphe

  **muscle group: anterior neck (suprahyoid)
• GENIOHYOID

  A: pulls hyoid bone superiorly and anteriorly

  O: Inner surface of mandibular symphysis

  I: hyoid bone

  **Muscle group: anterior neck (suprahyoid)
• STERNOHYOID

  A: depresses larynx and hyoid bone if mandible is fixed

  O: Manubrium and medial end of clavicle

  I: Lower margin of hyoid bone

  **Muscle group: anterior neck (infra hyoid)
• STERNOTHYROID

  A: pulls larynx and hyoid bone inferiorly 

  O: Posterior surface of manubrium of sternum

  I: thyroid cartilage

  *muscle group: anterior neck (infra hyoid)
• THYROHYOID

  A: depresses hyoid bone; elevates larynx if hyoid is fixed

  O: thyroid cartilage

  I: hyoid bone

  **Muscle group: anterior neck (infrahyoid)
• PHARYNGEAL CONSTRICTOR MUSCLE

  A: Constricts pharynx during swallowing

  O: Attached anteriorly to mandible and medial pterygoid plate; hyoid bone

  I: Posterior median raphe of pharynx

  **Muscle group: Anterior neck (infrahyoid)
• GENIOGLOSSUS

  A: Protracts tongue

  O: internal surface of mandible near symphysis

  I: Inferior aspect of the tongue; body of hyoid bone

  **Muscle group: tongue movement
• HYOGLOSSUS

  A: Depresses tongue; draws its sides downwards

  O: body and greater horn of hyoid bone

  I: inferolateral tongue

  **Muscle group: tongue movement
• STYLOGLSSUS

  A: retracts and elevates tongue

  O: Styloid bone of temporal bone

  I: inferolateral tongue

  **Muscle group: tongue movement