Back Muscles

Question 1

Latissimus Origin

Answer 1

• Lower 6 Thoracic
• Lower 3-4 ribs
• iliac crest

Question 2

Action of Lats

Answer 2

-Adduction, extension, medially rotates arm

Question 3

Lavator scapulae action and inn

Answer 3

• Elevates and rotates scapula inferiority

- Inn: ventral rami of C3 and C4, dorsal scapular nerve

Question 4

Rhomboid Major and Minor Origin

Answer 4

• Minor: C7, T1

- Major: T2-T5

Question 5

Action and innervation of rhomboid Major and minor

Answer 5

• Retract and rotate scapula inferiority

- Inn: dorsal scapular N

Question 6

Serratus Posterior Superior Origin

Answer 6

C7-T3

Question 7

Serratus posterior superior insertion, action, and inn

Answer 7

• Ins: ribs 2-5
• Action: elevates ribs 2-5
• Inn: Ventral rami of T2-T5

Question 8

Serratus Posterior Inferior Origin

Answer 8

T11-L2/L3

Question 9

Serratus posterior inferior insertion, action, and inn

Answer 9

• Insert: Lower 4 ribs
• Action: depress ribs 8-12
• Inn: Ventral rami of T9-T12

Question 10

Intrinsic (deep) back muscles all innervation by dorsal rami

Answer 10

-Splenius capitis, Splenius Cervicis, erector spinae, transversospinalis

Question 11

Splenius Capitis and cervicis origin

Answer 11

• Capitis: C7-T3

- Cervicis: T3-T6 both spinous

Question 12

Insertion of Splenius capitis

Answer 12

-Mastoid and superior nuchal line

Question 13

Insertion of Splenius cervicis muscle

Answer 13

-Transverse process of C1-C3

Question 14

Action of Splenius capitis and cervicis

Answer 14

• Bilateral: extension of head and neck

- Unilateral: lateral flexion to the side of the contracting muscle

Question 15

Action and inn of erector spinae

Answer 15

• Bilateral: extension of back
• Unilateral: flexion to the side of the contracting muscles, supports against gravity

-Inn: dorsal rami

Question 16

Action of the Transversospinalis muscles (semispinalis, multifidis, rotatores)

Answer 16

• Bilateral: extension of the spine
• *Unilateral: flexion of the spine to side of contracting muscles AND rotation of the spine to opposite side of contracting muscle AND shorter muscles main function is to stabilize the vertebral column

Question 17

Semispinalis Origin and Insertion

Answer 17

Origin: transverse process of C4-T12

Ins: Between superior and inferior nuchal lines

Question 18

Action and inn of semispinalis capitis

Answer 18

• Extension of head, thoracic, and cervical regions of the vertebral column; rotates these regions contralaterally
• Inn: dorsal rami of spinal n

Question 19

Minor intrinsic muscles

Answer 19

• Levatores costarum
• Interspinous m
• Intertransverse m

Question 20

Important contents of suboccipital triangle

Answer 20

• Vertebral A

- Suboccipital n

Question 21

Suboccipital muscles and their inn

Answer 21

• Rectus capitis posterior major
• Obliquus capitis superior
• Obliquus capitis inferior
• Rectus capitis posterior minor
• Inn: all by suboccipital N. Dorsal Ramos of C1

Question 22

Greater Occipital N

Answer 22

• Dorsal Ramos of C2

- Pierces trap and semispinalis