BIO 514 Unit 1 Content

What is a muscle’s ORIGIN?

A fixed attachment point where a muscle starts and attaches to bone.

What is a muscle’s INSERTION?

A point where a muscle attaches and moves during contraction.

Trapezius ORIGIN

• medial third of superior nuchal line

• External occipital protuberance

• Ligamentum nuchae

• Spinous processes of C7 - T12

Trapezius INSERTION

• lateral third of clavicle

• Acromion process

• spine of scapula

Trapezius ACTION

• superior fibers - ELEVATE scapula

• Middle fibers - RETRACT scapula

• Inferior fibers - DEPRESS scapula

Trapezius INNERVATION

Spinal accessory nerve (cranial nerve 11)

Latissimus dorsi ORIGIN

• spinous processes from T7 - sacrum

• Thoracolumbar fascia

• Iliac crest

• Lower ribs

Latissimus dorsi INSERTION

Floor of intertubercular groove

Latissimus dorsi ACTION

Extends, adducts, and medially rotates arm

Latissimus dorsi INNERVATION

Thoracodorsal nerve (middle scapular n; off brachial plexus)

Rhomboideus major ORIGIN

Spinous processes of T2 - T4

Rhomboideus major INSERTION

Medial border of the scapula

Rhomboideus major ACTION

Retracts and elevates scapula

Rhomboideus major INNERVATION

Dorsal scapular nerve (off brachial plexus)

Rhomboideus minor ORIGIN

• Spinous processes of C7 and T1

• Lower end of ligamentum nuchae

Rhomboideus minor INSERTION

Medial border of scapula

Rhomboideus minor ACTION

Retracts and elevates scapula

Rhomboideus minor INNERVATION

Dorsal scapular nerve (off brachial plexus)

Levator scapulae ORIGIN

Transverse processes of C1 - C4

Levator scapulae INSERTION

Superior part of medial border of scapula

Levator scapulae ACTION

Elevates scapula

Levator scapulae INNERVATION

Dorsal scapular nerve (off brachial plexus)

Upper part receives branches of C3 and C4

Serratus posterior superior ORIGIN

Nuchal ligament, spinous processes of C7-T3

Serratus posterior superior INSERTION

Ribs 2-5, lateral to angles

Serratus posterior superior ACTION

Elevates upper ribs

Serratus posterior superior INNERVATION

Thoracic ventral rami

Serratus posterior inferior ORIGIN

Thoracolumbar fascia, spinous processes of T11-L2

Serratus posterior inferior INSERTION

Ribs 9-12 lateral to angles

Serratus posterior inferior ACTION

Depresses lower ribs

Splenius ORIGIN

Nuchal ligament, spinous processes C7-T6

Splenius INSERTION

Transverse processes C1-C4, superior nuchal line, and mastoid process

Splenius ACTION (BILATERALLY)

Extends head and neck

Splenius ACTION (UNILATERALLY)

Laterally flexes head and neck, rotates head ipsilaterally

Splenius INNERVATION

Cervical ventral rami

Name the three erector spinae muscles:

Iliocostalis, longissimus, spinalis

Iliocostalis ORIGIN

Posterior sacrum, iliac crest, spinous and transverse processes of lower lumbar and sacral vertebrae

Iliocostalis INSERTION

Angles of ribs and transverse processes of C4-C6

Iliocostalis ACTION (BILATERALLY)

Extends vertebral column

Iliocostalis ACTION (UNILATERALLY)

Laterally flexes vertebral column

Iliocostalis INNERVATION

Dorsal rami

Longissimus ORIGIN

Posterior sacrum, iliac crest, spinous and transverse processes of lower lumbar and sacral vertebrae

Longissimus INSERTION

Transverse processes at superior vertebral levels and mastoid process

Longissimus ACTION (BILATERALLY)

Extends vertebral column and head

Longissimus ACTION (UNILATERALLY)

Laterally flexes vertebral column

Longissimus INNERVATION

Dorsal rami

Spinalis ORIGIN

• posterior sacrum

• Iliac crest

• Spinous and transverse processes of lower lumbar and sacral vertebrae

Spinalis INSERTION

• spinous processes at superior vertebral levels

• Base of skull

Spinalis ACTION (BILATERALLY)

Extends vertebral column and head

Spinalis ACTION (UNILATERALLY)

Laterally flexes vertebral column

Spinalis INNERVATION

Dorsal rami

Name the three muscles that make up transversospinalis:

• Semispinalis

• Multifidus

• Rotatores

Semispinalis ORIGIN

Transverse processes of C7-T12

Semispinalis INSERTION

• Spinous processes 4-6 vertebrae above origin

• Occipital bone between nuchal lines

Semispinalis ACTION (BILATERALLY)

Extends head and neck

Semispinalis ACTION (UNILATERALLY)

• laterally flexes neck and trunk

• Rotates trunk contralaterally

Semispinalis INNERVATION

Dorsal rami of cervical and thoracic regions

Multifidus ORIGIN

• sacrum

• Transverse processes of L5 to C3

Multifidus INSERTION

Spinous processes 2-4 vertebrae superior to origin

Multifidus ACTION (BILATERALLY)

Extends neck and trunk

Multifidus ACTION (UNILATERALLY)

• laterally flexes trunk

• Rotates trunk contralaterally

Multifidus INNERVATION

Dorsal rami

Rotatores ORIGIN

Transverse processes (most prominent in thoracic region)

Rotatores INSERTION

Spinous processes 1-2 vertebrae superior to origin

Rotatores ACTION

Rotates trunk contralaterally

Rotatores INNERVATION

Dorsal rami

Name the muscles that make up the suboccipital triangle:

• rectus capitis posterior major

• Rectus capitis posterior minor

• Obliquus capitis superior

• Obliquus capitis inferior

Rectus capitis posterior major ORIGIN

Spinous process of C 2 (axis)

Rectus capitis posterior major INSERTION

Inferior nuchal line

Rectus capitis posterior major ACTION

Extends and rotates head ipsilaterally

Rectus capitis posterior major INNERVATION

Dorsal ramus of C1 (suboccipital nerve)

Rectus capitis posterior minor ORIGIN

Posterior tubercle of C1 (atlas)

Rectus capitis posterior minor INSERTION

Medial portion of inferior nuchal line

Rectus capitis posterior minor ACTION

Extends the head

Rectus capitis posterior minor INNERVATION

Dorsal ramus of C1 (suboccipital nerve)

Obliquus capitis superior ORIGIN

Transverse process of C2 (atlas)

Obliquus capitis superior INSERTION

Occipital bone superior to inferior nuchal line

Obliquus capitis superior ACTION

Extends and rotates head ipsilaterally

Obliquus capitis superior INNERVATION

Dorsal ramus of C1 (suboccipital nerve)

Obliquus capitis inferior ORIGIN

Spinous process of C2 (axis)

Obliquus capitis inferior INSERTION

Transverse process of C1 (atlas)

Obliquus capitis inferior ACTION

Rotates head ipsilaterally

Obliquus capitis inferior INNERVATION

Dorsal ramus of C1 (suboccipital nerve)

Name this vertebrae

Cervical

Defining factor of cervical vertebrae

Foramina in transverse processes

Name this special cervical vertebrae and its defining factor

• C1

• Atlas

• No vertebral body

Name this special cervical vertebrae and its defining factor

• C2

• Axis

• Dens (adotoid process)

Name this cervical vertebrae and its defining factor

• C7

• Vertebra prominens

• Large spinous process

Name this vertebrae and its defining characteristic

• thoracic

• Costal facets on transverse processes

Name this vertebrae and its defining characteristic

• lumbar

• Large vertebral body

• “Stubby” processes

Name this part of the vertebral column that is FUSED

Sacrum

Name this part of the vertebral column that is FUSED

Coccyx

Identify the parts of the vertebrae (label from A to J)

A. Spinous process

B. Costal facet

C. Vertebral Body

D. Vertebral foremen

E. Pedicle

F. Superior Articular Facet

G. Inferior Articular Facet

H. Transverse Process

I. Vertebral Arch

J. Lamina

Gluteus maximus ORIGIN

• posterior ilium

• Sacrum

• Coccyx

• Sacrotuberous ligament

Gluteus maximus INSERTION

• superior fibers - iliotibial tract (IT band)

• Inferior fibers - gluteal tuberosity of femur

Gluteus maximus ACTION

Extends and laterally rotates thigh at hip

Gluteus maximus INNERVATION

Inferior gluteal nerve

Gluteus medius ORIGIN

Lateral surface of ilium between gluteal lines

Gluteus medius INSERTION

Lateral surface of greater trochanter of femur

Gluteus medius ACTION

• Abducts and medially rotates thigh at hip

• Stabilizes pelvis when opposite leg is lifted

Gluteus medius INNERVATION

Superior gluteal nerve