Back Muscles Flashcards
(18 cards)
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
