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Flashcards in Back Muscles Deck (18):
1

Trapezius

Type- superficial extrinsic back muscle- control limb movements

Innervation- motor: spinal accessory (CN XI), spinal root, proprioception: C3-C4
[XI- supplies trapezius and sternocleidomastoid (SCM-image)
SCM- paired muscle in the superficial layers of the side of the neck, one of the largest and most superficial cervical muscles.
rotation of the head to the opposite side and flexion of the neck]

Artery- transverse cervical a.

Action- Elevates, retracts and rotates scapula
-shrug shoulders, extend neck
-overhead abduction (rotation of scapula) of arm=traps/serratus anterior req for arm to abduct >90 deg/full abduction

Notes- Injury to spinal accessory- weakness of shrug
-named for its shape; trapezius is an example of a muscle that migrates during development from its level of origin (cervical) to its final position, pulling its nerve and artery along behind

Origin- Ligamentum nuchae; spines of C7-T12 [upper fibers go down, lower fibers up, middle fibers laterally to clavicle and scapula]

Insertion- Lateral clavicle, acromion, spine of scapula

2

Latissimus dorsi

Type- superficial extrinsic back muscle- control limb movements

Innervation- Thoracodorsal [most superficial extrinsic back muscles receive their nerve supply from anterior rami of cervical nerves]

Artery- Thoracodorsal artery

Action- Extends, adducts, medially rotates humerus
*used to wipe bottom*
-chin-up (lats and teres major active), swim, handcuff

Notes- “climbing muscle”- Cancer in Axillary Lymph Nodes, They try to remove the axillary lymph nodes that are cancerous are removed, and the Thoracodorsal nerve and Long Thoracic Nerve are commonly injured

Origin- Spines of T6-T12, thorocolumbar fascia, iliac crest

Insertion- Intertubercular sulcus of humerus aka bicipital groove

3

Levator scapulae

Type- superficial extrinsic back muscle- control limb movements

Innervation- Dorsal scapular C3-C4

Artery- Transverse cervical artery

Action- Elevates scapula, helps in the downward or medial rotation of the scapula

Notes- Only one that elevates other than trapezius
-strap-like

Origin- Transverse processes C2-C4

Insertion- Superior medial border of scapula

4

Rhomboid minor

Type- superficial extrinsic back muscle- control limb movements

Innervation- Dorsal scapular

Artery- Deep branch of transverse cervical, dorsal scapular artery

Action- Retracts and rotates scapula-pull scapula towards spine

Notes- Most powerful retractors of scapular, Smaller, above major

Origin- Spines of C7-T1

Insertion- Inferior medial border of scapula

5

Rhomboid major

Type- superficial extrinsic back muscle- control limb movements

Innervation- Dorsal scapular

Artery- Deep branch of transverse cervical, dorsal scapular artery

Action- Retracts and rotates scapula-pull scapula towards spine

Notes- Most powerful retractors of scapular

Origin- Spines of T2-T5

Insertion- Inferior medial border of scapula

6

Serratus posterior superior

Type- Intermediate Extrinsic Back Muscles- Control respiratory movements

Innervation- Intercostal nerves T2-T5

Artery- posterior intercostal aa. 1-4

Action- Elevates ribs

Notes- Important in asthma patients
-lies deep to rhomboids
-More likely proprioceptive rather than motor in function
-Serratus-bc serratedly (teeth-like) inserted into ribs (which aren’t continuous)

Origin- Spines of C7-T3

Insertion- Superior border of ribs 2-5

7

Serratus posterior inferior

Type- Intermediate Extrinsic Back Muscles- Control respiratory movements

Innervation- Intercostal nerves T9-T12

Artery- lowest posterior intercostal a., subcostal a., first two lumbar aa.

Action- Depresses ribs

Notes- Important in asthma patients
-lies deep to latissimus dorsi
-More likely proprioceptive rather than motor in function
-Serratus-bc serratedly (teeth-like) inserted into ribs (which aren’t continuous)

Origin- Spines of T11-L2

Insertion- Inferior border of ribs 8-12

8

Splenius capitis

Type- Superficial intrinsic

Innervation- Dorsal rami of the spinal nerves
[all intrinsic back m.-innervated by posterior rami of spinal nerves]

Artery- deep cervical a., posterior intercostal aa.

Action- Unilaterally: Laterally flex and rotate head
Together: extend head and neck

Notes- named for its shape: splenius=bandage and capitis refers to the insertion of this portion of the muscle

Origin- Ligamentum nuchae; Spinous processes of C7-T3/4

Insertion- mastoid, nuchal line

9

Spenius cervicis

Type- Superficial intrinsic

Innervation- Dorsal rami of the spinal nerves

Artery- deep cervical a., posterior intercostal aa.

Action- Unilaterally: Laterally flex and rotate head
Together: extend head and neck

Notes- named for its shape: splenius means bandage and cervicis refers to the insertion of this portion of the muscle

Origin- Ligamentum nuchae, Spinous processes of C7-T3/4

Insertion- Transverse processes C1-C4

10

Iliocostalis

Type- Intermediate layer: erector spinae- Intrinsic (deep) back muscles act on vertebral column and produce its movements and maintain posture- lie in "groove"
I Love Spaghetti- counteracted by abdominal muscles

Innervation- Dorsal rami of spinal nerves C4-S5

Artery- deep cervical a., posterior intercostal aa., subcostal aa., lumbar aa.

Action- Unilaterally: laterally flex column and head

Notes- the most lateral part of the erector spinae; it may be subdivided into lumborum, thoracis and cervicis portions

Origin- Spinous Processes of Sacrum and lumbar, iliac crest

Insertion- Angles of ribs

11

Longissimus

Type- Intermediate layer: erector spinae- Intrinsic (deep) back muscles act on vertebral column and produce its movements and maintain posture- lie in "groove"
I Love Spaghetti- counteracted by abdominal muscles

Innervation- dorsal primary rami of spinal nerves C1-S1

Artery- deep cervical a., posterior intercostal aa., subcostal aa., lumbar aa.

Action- extends and laterally bends the trunk, neck and head

Notes- the intermediate part of the erector spinae;it may be subdivided into thoracis, cervicis and capitis portions

Origin- transverse process at inferior vertebral levels

Insertion- transverse process at superior vertebral levels and mastoid process

12

Spinalis

Type- Intermediate layer: erector spinae- Intrinsic (deep) back muscles act on vertebral column and produce its movements and maintain posture- lie in "groove"
I Love Spaghetti- counteracted by abdominal muscles

Innervation- dorsal primary rami of spinal nerves C2-L3

Artery- deep cervical a., posterior intercostal aa., subcostal aa., lumbar aa.

Action- extends and laterally bends trunk and neck

Notes- most medial part of the erector spinae; may be subdivided into thoracis, cervicis and capitis portions

Origin- spinous processes at inferior vertebral levels

Insertion- spinous processes at superior vertebral levels and base of the skull

13

Semispinalis

Type- Deep layer: transversospinalis- Intrinsic (deep) back muscles act on vertebral column and produce its movements and maintain posture, lie in "gutters"

Innervation- dorsal primary rami of spinal nerves C1-T12

Artery- deep cervical a., posterior intercostal aa., subcostal aa., lumbar aa.

Action- extends the trunk and laterally bends the trunk, rotates the trunk to the opposite side
Imp for proprioception

Notes- three parts are named based on their insertions: capitis, cervicis and thoracis;
only upper part of spine- "semi"

Origin- transverse processes of C7-T12

Insertion- capitis: back of skull between nuchal lines; cervicis & thoracis: spines 4-6 vertebrae above origin

14

Multifidus

Type- Deep layer: transversospinalis- Intrinsic (deep) back muscles act on vertebral column and produce its movements and maintain posture, lie in "gutters"

Innervation- dorsal primary rami of spinal nerves C1-L5

Artery- deep cervical a., posterior intercostal aa., subcostal aa., lumbar aa.

Action- extend and laterally bend trunk and neck, rotate to opposite side
Impt for proprioception

Notes- (appears like long connected muscle descending btwn iliac crests)

Origin- sacrum, transverse processes of C3-L5

Insertion- spinous processes 2-4 vertebral levels superior to their origin

15

Rotatores

Type- Deep layer: transversospinalis- Intrinsic (deep) back muscles act on vertebral column and produce its movements and maintain posture, lie in "gutters"

Innervation- dorsal primary rami of spinal nerves C1-L5

Artery- deep cervical a., posterior intercostal aa., subcostal aa., lumbar aa.

Action- rotates the vertebral column to the opposite side;
PROPRIOCEPTION

Notes- (appears like short, zig zag muscles btwn TP and SP all the way down spine)

Origin- transverse processes

Insertion- long rotatores: spines 2 vertebrae above origin; short rotatores: spines 1 vertebrae above origin

16

Interspinales

Type- Minor deep layer

Innervation- Dorsal rami of spinal nerves

Artery-

Action- Aid in extension of rotation of column

Notes- these are small and fairly insignificant muscles

Origin- C and L spinous processes

Insertion- Spinous process above

17

Intertransversarii

Type- Minor deep layer

Innervation- Dorsal rami of spinal nerves

Artery-

Action- Aid in lateral flexion of column

Notes- these are small and fairly insignificant muscles

Origin- C and L transverse processes

Insertion- Transverse processes above

18

Levatore costarum

Type- Minor deep layer

Innervation- Dorsal rami of spinal nerves

Artery-

Action- Elevate ribs, aid in lateral flexion

Notes- these are small and fairly insignificant muscles

Origin- Tips of transverse processes C7-T11

Insertion- Ribs, between tubercle and angle