Hypaxial and Epaxial Muscles

Question 1

Latissimus Dorsi
Origin
Insertion
Action
Innervation

Answer 1

Hypaxial (ventral rami)
SP Thoracic vertebrae, thoracolumbar fascia,iliac crest, last 3/4 ribs
Intertubercular groove
Extend/adduct back, med rotate arm
Thoracodorsal n C6-C8

Question 2

Trapezius
Origin
Insertion
Action
Innervation

Answer 2

Hypaxial (ventral rami)
occipital bone, ligamentum nuchae, SP C7-T12
clavicle, acromion, spine of scapula
elevate, retract, rotate scapula
Cranial nerve XI and C3-C4

Question 3

Rhomboid major and minor
Origin
Insertion
Action
Innervation

Answer 3

Hypaxial (ventral rami)
major: SP T2-T5, minor: nuchal ligament, SP C7-T1
medial border of scapula
Dorsal scapular n. C4-C5
Retract, rotate, fix scapula to thoracic wall

Question 4

Levator Scapulae
Origin
Insertion
Action
Innervation

Answer 4

Hypaxial (ventral rami)
TP C1-C4
Medial border scapula
C3-C4 and dorsal scapular C5
Elevate

Question 5

Serratus Posterior Superior
Origin
Insertion
Action
Innervation

Answer 5

Hypaxial (ventral rami)
Ligamentum nuchae and SP C7-T3
Ribs 2-4
Elevate ribs
T1-T4

Question 6

Serratus Posterior Inferior
Origin
Insertion
Action
Innervation

Answer 6

Hypaxial (ventral rami)
SP T11-L2
Ribs 9-12
Depress ribs
T9-T12

Question 7

Splenius capitis

Answer 7

nuchal ligament, SP C7-T3 (SP)
Mastoid
Cervical dorsal
extend head, lat bend and rotate

Question 8

Erector spinae
Iliocostalis
Longissimus
Spinalis

Answer 8

All origin are thoracolumbar fascia
Iliocostalis insertions: cervicis- TP
thoracis- upper 6 ribs
lumbarum- lower 6 ribs
Longissimus insertions: capitis- mastoid
cervicis- TP
thoracis- TP
Spinalis insertions: thoracis- SP
Extends and laterally bends
Dorsal n of the region

Question 9

Semispinalis

Answer 9

semispinalis capitis- origin=TP, insertion= Sup nuchal line
semispinalis cervicis-origin=TP, insertion= C2-C7
semispinalis thoracis-origin/insertion= thoracic TP/SP
dorsal cervical, thoracic
extension, opp. side rotation

Question 10

Multifidus

Answer 10

origin TP, insertion SP, span 2-4 vertebrae
dorsal n of region
stabilize spine

Question 11

Rotatores

Answer 11

TP
lamina and TP, span 1-2 vertebrae
dorsal n of region
stabilze, extend, rotate

Question 12

Splenius cervicis

Answer 12

SP T3-T6
TP C1-C3
lower dorsal cervical n
extend neck, laterally bends and rotates