The Back

Question 1

What structures make up the pectoral girdle?

Answer 1

The clavicle, scapula and humerus

Question 2

What ligaments are associated with the pectorial girdle?

Answer 2

Acromioclavicular

• coacoacromial
• glenohumeral
• scapulothoracic joint
• anterior sternal clavicular joint/ ligament

Question 3

What is another name for Hypaxial muscle and what do they do?

Answer 3

-Extrinsic Muscles
-Move limbs.
Innervated by CN XI or brachial plexus branches

Question 4

Intrinsic Muscles are innervated by what and are associated with muscles where?

Answer 4

• Support upright posture, and vertebral column movements
• proprioception
• Innervated by dorsal rami spinal nerves

Question 5

What are the most superficial layers of back muscles?

Answer 5

Trapezius, and latissimus dorsi

Question 6

What are muscles are deep to the trapezius and the latissimus dorsi?

Answer 6

• levator scapulae
• rhomboid major
• rhomboid minor

Question 7

Explain what a axioappencidular muscle is…

Answer 7

Posterior muscle attaching the scapula and humerus to the axial skeleton. and/or scapula to the humerus.

Question 8

What nerve innervates the scapula and the rhomboids?

Answer 8

CN IV

Question 9

Describe the trapezius. (origin, insertion, actions, innervation)

Answer 9

• Origin: ext. occipital protuberance, nuchal ligament, C7-T12 spinous process.
• Insertion: ant. lateral 3rd clavicle. acromion, scapular spine.
• Action: elevation, depression, retraction of scapula. Superior rotation of glenoid fossa
• Innervation: motor: CN XI. sernory: Ventral rami C3/C4

Question 10

Latissimus dorsi (actions, origin, insertion, innervation)

Answer 10

-Origin: Iliac crest, inferior 3 ribs, inferior thoracic vertebra 6, thoracolumbar fascia.
-Insertion: Intertubercular sulcus of humerus
-ACtion: extend, adduct, medial rotation.
Innervation: thoracodorsal nerve

Question 11

What muscle compose the deep posterior axioappendicular muscles, that are still superficial/hypaxial

Answer 11

• Levator Scapula
• Rhomboid Major
• Rhomboid Minor
• these are supplied by thoracodorsal artery/veins and nerve

Question 12

Rhomboid Major…

Answer 12

• origin:T2-T5 spinous process
• insertion: medial border of scapula from spine to inferior angle.
• action: retract, elevate, rotate scapula down. Fix to thoracic wall also.
• innervation: dorsal scapular nerve. Motor: C3/C4

Question 13

Rhomboid Minor…

Answer 13

• origin: nuchal ligament, c7 and t1 spinous process
• insertion: medial end of scapular spine
• action: retract, elevate, rotate down scapula.
• innervation: dorsal scapular nerve, Motor: c3/c4

Question 14

Levator Scapula

Answer 14

• origin: posterior tubercle of transverse process of c1-c4
• insertion: medial scapular border, superior scapular spine
• action: elevate scapula, inferior rotation of glenoid fossa.
• innervation: dorsal scapular nerve, ventral rami of cervical spine nerves

Question 15

What muscles compose the Extrinsic back Muscles?

Answer 15

• Serratus posterior superior
• serratus posterior inferior
• compose the third layer of muscles. Provide the postural and rotation of the vertebral column

Question 16

Serratus Posterior Superior

Answer 16

• origin: nuchal ligament, c7-t3 spinous process
• insertion: superior border of ribs 2-4
• action: elevate the ribs
• innervation: t2-t5 intercostal nerves (ventral rami)

Question 17

Serratus Posterior Inferior

Answer 17

• origin: t11-l2 spinous process
• insertion: inferior border of ribs 8-12
• action: depression of the ribs
• innervation: intercostal nerve and subcostal nerve

Question 18

What is the deepest group of major epaxial muscles, and the components from deepest to superficial?

Answer 18

• Transversospinalis group
• -rotatores
• -multifidus
• -semispinalis

Question 19

What is the more superficial layer of epaxial back muscles, labeled deepest to superficial?

Answer 19

• Erector spina group
• -Spinalis
• -Longissimus
• -Iliocostalis

Question 20

Of the Hypaxial muscle group, list muscles from deepest to superficial.

Answer 20

-serratus posterior
-latissimus dorsi
-trapezius (roughly)
have some amount of overlap

Question 21

The splenius back muscle.

Answer 21

Composed of the splenius cervicis and splenius capitis

Question 22

Splenius Cervicis

Answer 22

• origin: nuchal ligament and t1-t6 spinous process
• insertion: transverse tubercles of c1-c4
• action: extend head and neck or rotate head
• innervation: dorsal rami

Question 23

Splenius Capitis

Answer 23

• origin: nuchal ligament and t1-t6 spinous process
• insertion: lateral aspect of mastoid process, superior nuchal line
• action: extend,flex head neck. rotation when one is activated
• innervation: dorsal rami

Question 24

Muscles of the erector spinae group

Answer 24

• iliocostalis
• longissimus
• spinalis
• -innervated: dorsal rami of spinal nerves.
• -extension/ or lateral flexion

Question 25

Iliocostalis muscle

Answer 25

- most lateral muscle - origin:iliac crest, post sacrum, sacroiliac ligament, sacral and inferior lumbar spinous process, supraspinous ligament. - insertion: lumbar section (rib 6-12) thoracic (rib 1-6) cervicis (ribs 1-6, post tubercle of c4-c6)

Question 26

Longissimus Cervicis muscle

Answer 26

- origin: transverse process of cervical vertebra | - insertion: transverse process of cervical vertebra

Question 27

Longissimus Thoracis Muscle

Answer 27

- origin: iliac crest, post sacrum, sacroiliac ligament, sacral and inferior lumbar spinous process, supraspinous ligament. - insertion: ribs and adjacent transverse process of thoracic vertebra

Question 28

Longissimus Capitis muscle

Answer 28

- origin: transverse process of cervical vertebra | - insertion: mastiod process

Question 29

Spinalis Thoracis muscle

Answer 29

- origin: the spinous process | - insertion: spinous process superior to origin

Question 30

Spinalis Cervicis and Capitis muscle

Answer 30

difficult to differentiate and capitis may be missing in some cases

Question 31

Intrinsic back muscles (transversospinalis group)

Answer 31

- innervated: dorsal rami or spinal nerves. | - the deep layer consisting of: semispinalis, rotatores, and mutltifidus

Question 32

Semispinalis Cervicis muscle

Answer 32

- cervical to spinous process of 2nd vertebra. - action: extend head and rotate contralaterally - innervation: dorsal rami of spinal nerve

Question 33

Semispinalis Capitis muscle

Answer 33

- origin: connects superficial to cervicis - insertion: transverse process t1-t6 to nuchal line. - action: extend head, thoracic, and cervical region. contralateral rotation.

Question 34

Semispinalis Thoracis muscle

Answer 34

- origin: transverse process of t1-t12 - insertion: spinous process t1-t12 action: extend head, thoracic, and cervical region. contralateral rotation.

Question 35

Multifidus

Answer 35

- cover lamina and span the vertebral segments from sacrum to c2. - origin: transverse process - insertion: spinous process - action: stabilize vertebra during localized movements of vertebral column

Question 36

Rotatores Brevis muscle

Answer 36

- origin: transverse process - insertion: base of spinous process superior to the origin vertebra - action:extend head, thoracic, and cervical region. contralateral rotation.

Question 37

Rotatores Longus muscle:

Answer 37

- origin:transverse process of on vertebra - insertion: base of spinous process of 2nd vertebra suprior. spans two IV disks. - action: extend head, thoracic, and cervical region. contralateral rotation.