Insertions, Origins, & Actions of the head, neck, and back muscles

Where are the origins of the occipitofrontalis?

occipital bone, frontal bone

What are the actions of the occipitofrontalis?

elevation of eyebrows, creases skin of forehead, moves scalp backward & forward

What is the insertion of the occipitofrontalis?

epicranial aponeurosis (frontal bone)

What cranial nerve innervates the occipitofrontalis?

facial nerve (CN VII)

What are the origins of the orbicularis oculi?

frontal bone, maxilla

What are the insertions of the orbicularis oculi?

lateral side of eye

What is the action of the orbicularis oculi?

closes eyelids

What cranial nerve innervates the orbicularis oculi?

facial, CN VII

What are the origins of the orbicularis oris?

skin around mouth, mandible, maxilla

What are the insertions of the orbicularis oris?

lips, opposite side

What is the action of the orbicularis oris?

closes lips, pucker

What cranial nerve innervates the orbicularis oris?

facial nerve (CN VII)

What is the origin of the masseter?

zygomatic arch

What is the insertion of the masseter?

mandible

What is the action of the masseter?

elevation and protraction of mandible (chewing)

What cranial nerves innervates the masseter?

trigeminal nerve (CN V)

What is the origin of the temporalis?

temporal fossa

What is the insertion of the temporalis?

mandible

What cranial nerve innervates the temporalis?

trigeminal nerve (CN V)

What are the origins of the sternocleidomastoid?

clavicle, sternum

What are the insertions of the sternocleidomastoid?

mastoid process of temporal bone, superior nuchal line of the occipital bone

What are the actions of the sternocleidomastoid?

unilateral rotation of head, bilateral flexion of neck and bilateral extension of the head

What cranial nerve innervates the sternocleidomastoid?

accessory nerve (CN XI)

What is the origin of the scalene?

transverse processes of C3-7 vertebrae

What are the insertions of the scalene?

ribs 1 & 2

What are the actions of the scalene muscle?

elevation of rib 1, lateral flexion & rotation of neck

What nerve innervates the scalene?

ventral rami of cervical spinal nerves

What is the origin of the upper trapezius?

occipital bone

What are the insertions of the upper trapezius?

clavicle, acromion

What are the actions of the upper trapezius?

elevation, upward rotation

What cranial nerve innervates the upper trap?

accessory nerve (CN XI)

What are the origins of the middle trapezius?

cervical and thoracic vertebrae

What is the insertion of the middle trapezius?

spine of scapula

What is the action of the middle trapezius?

retraction

What cranial nerve innervates the middle trapezius?

accessory nerve (CN XI)

What is the origin of the lower trapezius?

lower thoracic vertebrae

What is the insertion of the lower trapezius?

base of spine of the scapula

What are the actions of the lower trapezius?

depression, upward rotation

What cranial nerve innervates the lower trapezius?

accessory nerve (CN XI)

What are the origins of the rhomboid major?

T2-T5

What is the insertion of the rhomboid major?

medial border of scapula

What is the action of the rhomboid major?

scapular retraction

What nerve innervates the rhomboid major?

posterior scapular nerve

What are the origins of the rhomboid minor?

ligamentum nuchae, C7-T1

What is the insertion of the rhomboid minor?

medial border of scapula

What are the origins of the iliocostalis (erector spinae)?

ligamentum nuchae, ribs 3-12, thoracic and lumbar vertebrae, sacral crests, thoracolumbar fascia

What are the insertions of the iliocostalis (erector spinae)?

mastoid process, cervical and thoracic vertebrae, all ribs

What are the actions of the iliocostalis (erector spinae)?

spinal extension, ipsilateral lateral flexion, ipsilateral rotation of the head

What nerves innervate the iliocostalis (erector spinae)?

cervical and lumbar spinal nerves

What are the origins of the longissimus (erector spinae)?

ligamentum nuchae, ribs 3-12, thoracic and lumbar vertebrae, sacral crests and thoracolumbar fascia

What are the insertions of the longissimus (erector spinae)?

mastoid process, cervical and thoracic vertebrae, all ribs

What are the actions of the longissimus (erector spinae)?

spinal extension, ipsilateral lateral flexion, ipsilateral rotation of the head

What nerve innervates the longissimus (erector spinae)?

cervical and lumbar spinal nerves

What are the origins of the spinalis (erector spinae)?

ligamentum nuchae, ribs 3-12, thoracic and lumbar vertebrae, sacral crests and thoracolumbar fascia

What are the insertions of the spinalis (erector spinae)?

mastoid process, cervical and thoracic vertebrae, all ribs

What are the actions of the spinalis (erector spinae)?

spinal extension, ipsilateral lateral flexion, ipsilateral rotation of the head

What are the nerves that innervate the spinalis (erector spinae)?

cervical and lumbar spinal nerves

What is the origin of the quadratus lumborum?

posterior iliac crest

What are the insertions of the quadratus lumborum?

T12-L4, Rib 12

What are the actions of the quadratus lumborum?

L/S extension, ipsilateral lateral flexion, fixes rib 12, stabilizing diaphragm

What nerves innervate the quadratus lumborum?

T12-L4

What are the origins of the pectoralis minor?

ribs 3-5

What is the insertion of the pectoralis minor?

scapula (coracoid process)

What nerves innervate the pectoralis minor?

medial and lateral pectoral nerves

What are the origins of the serratus anterior?

ribs 1-8

What is the insertion of the serratus anterior?

medial border of scapula

What is the action of the serratus anterior?

scapular protraction

What nerve innervates the serratus anterior?

long thoracic nerve

What is the origin of the rectus abdominis?

pubis

What are the insertions of the rectus abdominis?

ribs 5-7, xiphoid process

What is the action of the rectus abdominis?

forward flexion

What are the origins of the external oblique?

ribs 5-12

What are the insertions of the external oblique?

linda alba, iliac crest, pubis

What are the actions of the external oblique?

forward flexion, ipsilateral lateral flexion, contralateral rotation

What nerves innervate the external obliques?

spinal nerves T7-T12

What is the origin of the internal oblique?

iliac crest

What is the insertion of the internal oblique?

linda alba, ribs 10-12

What are the actions of the internal oblique?

forward flexion, ipsilateral lateral flexion, ipsilateral rotation

What nerve innervates the internal oblique?

spinal nerves T7-L1

What are the origins of the transverse abdominis?

inguinal ligament, iliac crests, thoracolumbar fascia, ribs 7-12 (cartilages)

What are the insertions of the transverse abdominis?

linea alba, pubis, aponeurosis of internal abdominal oblique

What is the action of the transverse abdominis?

compresses the abdominal cavity

What nerve innervates the transverse abdominis?

spinal nerves T7-L1

What is the action of the rhomboid minor?

scapular retraction

What nerve innervates the rhomboid minor?

posterior scapular nerve

What are the origins of the latissimus dorsi?

T7-T12, iliac crest, lower ribs

What is the insertion of the latissimus dorsi?

intertubecular groove of the humerus

What are the actions of the latissimus dorsi?

medial rotation of humerus, shoulder adduction, shoulder extension