Anatomy - Back 2

Front 1

extrinsic back muscles

Back 1

-superficially located
-move upper extremities or involved in respiration
-trapezius m.
-latissimus dorsi m,
-rhomboid minor & major mm.
-levator scapulae m.
-posterior superior & inferior serratus mm.

Front 2

triangle of auscultation

Back 2

-located at 6th intercostal space
-the space between the lower
border of the trapezius, the upper border of the latissimus dorsi, and medial border of the scapula is covered only by skin and intercostal muscles
-good place for listening to thoracic sounds

Front 3

trapezius muscle

Back 3

-origin: external occipital protuberance, superior nuchal line, midline: nuchal ligament and spines of all thoracic vertebrae
-Insertion: spine of scapula, lateral third of clavicle and acromion
-Nerve: cranial nerve XI - the spinal accessory nerve
-Function: elevates, retracts and rotates scapula to face the glenoid cavity superiorly (this needed for full aBduction of the arm); the trapezius can also depress the scapula (when just the inferior fibers are
used)
-Arterial supply: superficial branch of transverse cervical a (superficial cervical a)

Front 4

latissuimus dorsi muscle

Back 4

-Origin: iliac crest, spine of T6, thoracolumbar fascia, inferior 3-4 ribs.
-Insertion: floor of intertubercular (bicipital) groove of humerus
-Nerve: thoracodorsal nerve
-Function: adduct, extend and medially rotates the humerus (e.g. picture the power stroke of swimming)
-Arterial supply: thoracodorsal artery

Front 5

levator scapulae muscle

Back 5

-Origin: transverse process of C1-C4
-Insertion: scapula between superior angle and root of scapular spine (the medial upper border of the scapula)
-Nerve: dorsal scapular n
-Function: elevates scapula or inclines neck if scapula is fixed)
-Arterial supply: deep branch of transverse cervical a

Front 6

rhomboids - major & minor

Back 6

-Origin: vertebral spines --> Rhomboid Minor from C7-T1, Rhomboid Major from T2-5
-Insertion: medial scapula (r. minor inserts more superiorly than the r. major)
-Nerve: dorsal scapular n
-Function: adduct and rotate scapula
-Arterial: deep branch of transverse cervical a

Front 7

posterior serratus muscles

Back 7

-very thin
-assist in repiration
-The superior group extends from the spinous process of C7-T3 and inserts on the superior border of ribs 2-5
-The inferior group originates from the spinous processes of T11-L2 and inserts on the inferior border of the lower 3-4 ribs

Front 8

intrinsic back muscles

Back 8

-extend the vetebral column/head
-rotate the vertebral column/head
-innervated by dorsal rami of spinal nerves
-splenius mm.
-erector spinae mm.
-transversospinalis mm.

Front 9

splenius capitus m.

Back 9

-Origin: lower half of ligamentum nuchae, spines of C7-T3
-Insertion: mastoid process of temporal bone and lateral part of occipital bone
-Nerve: dorsal rami (no name)
-Function: together they extend head, acting alone they laterally flex the head with slight rotation of the head
-Arterial supply: superficial branch of transverse cervical

Front 10

splenius cervicis m.

Back 10

-Origin: spines of T3-T6
-Insertion: transverse processes of upper 3-4 cervical vertebrae (Note this muscle is mostly covered by the splenius capitus)
-Nerve: dorsal rami
-Function: acting together they extend the neck, acting alone they laterally flex neck and thus the head.
-Arterial supply: superficial branch of transverse cervical

Front 11

iliocostalis m.

Back 11

-Origins: iliac crest, sacrum, and lower ribs.
-Insertion: ribs and transverse process of vertebrae.

Front 12

longissimus m.

Back 12

-Origin: Generally these arise from transverse processes of vertebrae
-Insertion: transverse processes of more superior vertebrae as well as onto ribs

Front 13

spinalis m.

Back 13

-Origin: spinous processes of vertebrae
-Insertion: spinous processes of higher vertebrae and occipital bone

Front 14

transversospinalis muscle group

Back 14

-deep layer of intrinsic back muscle

Front 15

semispinalis mm.

Back 15

-only T10 and superior
-3 divisions: capitis, cervicis, and thoracis
-The semispinalis thoracis and
semispinalis cervicis originate from transverse processes of thoracic vertebrae and generally insert onto spines of hhigher vertebrae.

Front 16

multifidus mm.

Back 16

-represented in the entire vertebral column but are heaviest and best developed in the lumbar region
-these muscles span 2-5 vertebrae, originating from a transverse processes and inserting on the base of a vertebral spine(s)

Front 17

rotatores mm.

Back 17

-best studied & tested on diagrams due to small size
-rotatores longus: they originate from a transverse process and insert on the spinous process of a more superior vertebrae
-rotatores brevis: arise from a transverse process of one vertebrae and insert into the base of the spinous process immediately superior to it

Front 18

suboccipital region

Back 18

Nerves
-C1 --> suboccipital n.
-C2 --> greater occipital n.

Muscles
-Rectus Capitis Posterior Minor
-Rectus Capitis Posterior Major
-Oblique Capitis Superior
-Oblique Capitus Inferior

Arteries
-vertebral artery

Front 19

rectus capitus posterior minor

Back 19

-Origin: posterior tubercle of atlas C1
-Insertion: occipital bone
-extend & laterally rotate head

Front 20

rectus capitus posterior major

Back 20

-inferior & lateral to minor
-Origin: axis (C2) spine
-Insertion: occipital bone
-extend & laterally rotate head

Front 21

oblique capitus superior

Back 21

-Origin: transverse process of the atlas C1
-Insertion: occipital bone
-laterally rotate the head
-aids in extension of head

Front 22

oblique capitus inferior

Back 22

-Origin: spine of axis (C2)
-Insertion: transverse process of the atlas (C1)
-laterally rotate the head