A&P 1 Muscles

Action: elevates eyebrows and wrinkles skin of forehead

Origin: epicranial aponeurosis

Insertion: skin of eyebrow and bridge of nose

Action: pulls scalp posterior; wrinkles skin on posterior surface of neck

origin: superior nuchal line on occipital bone

insertion: epicranial aponeurosis (Galea aponeurotica)

Action: compresses nostrils, dilates nostrils

origin: maxillary bone and cartilage of nose

insertion: bridge of nose

action: closes eyelids; acts during squinting and blinking

origin: medial aspect of bony orbit

insertion: skin around eyelids

action: closes and purses lips as in speaking, kissing and whistling

origin: medial bone; mandible

insertion: lips

action: elevates corner of mouth

origin: zygomatic bone

insertion: angle of mouth

action: raises upper lip

origin: zygomatic bone

insertion: upper lip

action: protudes lower lip; wrinkles skin on chin

origin: anterior surface of mandible

insertion: skin of chin

action: draws corner of mouth laterally

origin: fascia of masseter

insertion: corner of mouth

action: elevates mandible to close jaw; protudes mandible

origin: zygomatic arch

insertion: lateral surface of the mandibular ramus

action: elevates and retracts mandible to close jaw

origin: temporal bone

insertion: coronoid process of mandible

action: flexion and lateral flexion of neck; rotates head so that face is turned superiorly and to the opposite side

origin: manubrium; medial third of clavicle

insertion: mastoid process

action: depresses and retracts hyoid bone

• superior belly
•     origin: clavicle and first rib
•     insertion: hyoid bone
• inferior belly
•     origin: superior margin of scapula
•     insertion: clavicle and first rib

action: depresses hyoid bone; elevates larynx

origin: thyroid cartilage of larynx

insertion: hyoid bone

action: depresses larynx and hyoid bone during swallowing

origin: manubrium

insertion: hyoid bone

action: elevates and retracts hyoid bone during swallowing and speaking

origin: styloid process of temporal bone

insertion: hyoid bone

Action: elevates hyoid bone and floor of mouth during swallowing and speaking

origin: inferior margin of mandible

insertion: hyoid bone

action: elevates hyoid bone and base of tongue, depresses mandible

origin: inferior margin of mandible

insertion; hyoid bone

action: moves hyoid bone back

origin: mastoid process

insertion:hyoid bone

action: laterally flexes of neck; elevates rib 1 during forced inspiration

origin: transverse process of cervical vertebrae

insertion: 1st rib

action: lateral flexion of neck; elevates rib 1 during forced inspiration

origin: transverse process of cervical vertebrae

insertion: 1st rib

action: elevates 2nd rib

origin: transverse processes of cervical vertebrae

insertion: 2nd rib

action: elevates scapula and inferior rotation of scapula

origin: transverse processes of superior four cervical vertebrae

insertion: medial border of scapula near superior angle

Action: adducts scapula and performs downward rotation

origin: Ligamentum nuchae; spinous processes of vertebrae c7 and T1

Insertion: medial border of scapula

Action: Adducts scapula and performs downward rotation

origin: spinous processes of vertebrae T2-T5

insertion: medial border of scapula

Action: elevate, retracts and depresses scapula

origin; posterior surface of occipital bone; ligament nuchae; spinous processes of thoracic vertebrae

Insertion: lateral third of clavicle; acromion; spine of scapula

Action: extension, adduction and medial rotation of arm

origin: spinous processes of vertebrae T6-T12; thoracolubar fascia; iliac crest; inferior three ribs

Insertion; intertubercular groove of humerus

Action: Extension of vertebral column

Origin: Thoracolumbar fascia; posterior surface of lacrum; iliac crest; spinous processes of T11-T12 and L1-L5

• Insertion:
•      Iliocostalis: angles of ribs and transerve processes of C4-C6
•      Longissimus: transverse processes of thoracic and cervical vertrabe, ect.
•       Spinalis: Spinous processes of thoracic and cervical vertebrae

Action: pulls ribs down, resisting pull of the diaphragm

origin: spinous processes of the lower two thoracic and upper two or three lumbar vertebrae

insertion: lower borders of the bottom four ribs

•Action: Extension of head and neck; lateral flexion and rotation of the head and neck


•Origin: Spinous processes of inferior cervical and superior thoracic vertebrae


•Insertion: mastoid process, occipital bone, and transverse processes of superior cervical vertebrae

•Action: Depresses rib cage during forced expiration


• Origin: Superior border of inferior rib


•Insertion: Inferior border of superior rib

•Action: Elevates rib cage during inspiration


•Origin: Inferior border of superior rib


•Insertion: Superior border of inferior rib

• •Action: Holds scapula to chest wall,
• •Protraction and superior rotation of scapula
• •Origin: External surfaces of ribs 1-8
• •Insertion: Medial border of scapula

• •Action: Draws scapula down and forward and elevates ribs
• •Origin: External surfaces of ribs 3-5
• •Insertion: Coracoid process of scapula

Action: Flexes, adducts, and medially rotates humerus, draws body upward in climbing


Origin: Medial half of clavicle; sternum; costal cartilages of ribs 1-6


Insertion: lateral lip of intertubercular groove on humerus

• •Action: Adduction and medial rotation of arm.
• •Origin: Subscapular fossa of scapula
• •Insertion: lesser tubercle of humerus

• •Action: Abduction of arm
• •Origin: supraspinous fossa of scapula
• •Insertion: Greater tubercle of humerus

• •Action:  Lateral rotation of arm
• •Origin: Infraspinous fossa of scapula
• •Insertion: Greater tubercle of humerus

• •Action:  Lateral rotation of the arm
• •Origin: Lateral border of scapula
• •Insertion: Greater tubercle of humerus

• •Action: Extension, adduction and medial rotation of arm
• •Origin: Scapula, near inferior angle
• •Insertion: medial lip of intertubercular groove of the humerus

• Action:
•     •Anterior fibers: medial rotation and flexion of arm
•     •Middle fibers: abduction of arm
•     •Posterior fibers: lateral rotation and extension of arm

•Origin: Lateral third of clavicle; acromion process; spine of scapula


•Insertion: Deltoid tuberosity of humerus

• •Action: Increases volume of thoracic cavity by pulling central tendon inferiorly
• •Origin: Xiphoid process and inferior six ribs
• •Insertion: central tendon of diaphragm

• •Action: Tenses abdominal wall and flexes vertebral column
• •Origin: Pubic crest; pubic symphysis
• •Insertion: Xiphoid process, costal cartilages of ribs 5-7

• •Action: Compresses abdomen, contralaterally rotates and flexes vertebral column
• •Origin: External surfaces of inferior 8 ribs.
• Insertion: Linea alba; pubic crest; pubic tubercle; iliac crest

• •Action: Compresses abdomen, ipsilaterally rotates and flexes vertebral column
• •Origin: Thoracolumbar fascia; iliac crest; inguinal ligament
• Insertion: Linea alba; pubic crest; inferior three or four ribs

• •Action: Compresses abdomen
• •Origin: Thoracolumbar fascia; inguinal ligament; costal cartilages of inferior six ribs; iliac crest
• •Insertion: linea alba; pubic crest

• •Action: Flexion and supination of forearm; flexion of arm
• •Origin: Long head: superior margin of glenoid fossa of scapula
• •Short head: coracoid process of scapula
• •Insertion: radial tuberosity of radius

• •Action: Flexion of forearm
• •Origin: Anterior surface  of humerus
• •Insertion: Coronoid process of ulna

• •Action: Flexion and adduction of arm
• •Origin: Coracoid process of scapula
• •Insertion: Medial surface of humerus

Action:  Extension of forearm; long head extends and adducts arm

• Origin: Long head: inferior margin of glenoid fossa
•      •Lateral head: posterior surface of humerus
•      •Medial head: posterior surface inferior to lateral head

•Insertion: Olecranon process of ulna