Muscles of the Neck and Back

Question 1

Which muscle divides the anterior and posterior anatomical triangles of the neck?

Answer 1

Sternocleidomastoid

Question 2

2 groups of muscles that move hyoid bone

Answer 2

• Suprahyoid muscles
• Infrahyoid muscles

Question 3

Suprahyoid muscles

Answer 3

• Digastric
• Mylohyoid
• Stylohyoid
• Geniohyoid

Question 4

Action of suprahyoid muscles

Answer 4

Elevate hyoid and larynx during swallowing

Question 5

Infrahyoid muscles

Answer 5

• Thyrohyoid
• Sternothyroid
• Sternohyoid
• Omohyoid

Question 6

Action of infrahyoid muscles

Answer 6

Depress hyoid and larynx during swallowing and speech

Question 7

2 muscle groups of the body wall

Answer 7

• Anterolateral muscle wall
• Posterior muscle wall

Question 8

What does the fascial covering of the neck and back attach to medially?

Answer 8

• Ligamentum nuchae
• Tips of spinous processes
• Supraspinal ligament of entire vertebral column
• Median crest of sacrum

Question 9

2 broad groups of muscles of the back

Answer 9

• Extrinsic muscles
• Intrinsic muscles

Question 10

2 groups of extrinsic back muscles

Answer 10

• Superficial
• Intermediate

Question 11

Superficial extrinsic back muscles

Answer 11

• Trapezius
• Latissimus dorsi
• Levator scapulae
• Rhomboid major
• Rhomboid minor

Question 12

Origin, insertion and action of trapezius

Answer 12

• Descending part (superior fibres)
  > O = medial 1/3 of superior nuchal line, external occipital protuberance, nuchal ligament
  > I = lateral 1/3 of clavicle
  > A = draws scapula superomedially, extension + lateral flexion of head + neck, rotation of head
• Transverse part (middle fibres)
  > O = spinous processes + supraspinous ligaments of T1-4
  > I = medial acromial margin, superior crest of spine of scapula
  > A = draws scapula medially
• Ascending part (inferior fibres)
  > O = spinous processes + supraspinous ligaments of T4-12
  > I = latera apex of medial end of scapular spine
  > A = draws scapula inferomedially

Question 13

Motor innervation of trapezius

Answer 13

Accessory nerve (CNXI)

Question 14

Origin, insertion and action of latissimus dorsi

Answer 14

• Origin
  > Vertebral part = spinous processes of T7-12, thoracolumbar fascia
  > Iliac part = posterior 1/3 of crest of ilium
  > Costal part = ribs 9-12
  > Scapular part = inferior angle of scapula
• Insertion = intertubercular sulcus of humerus
• Action = arm internal rotation, adduction + extension (+ assists respiration)

Question 15

Innervation of latissimus dorsi

Answer 15

Thoracodorsal nerve (C6-8)

Question 16

Origin, insertion and action of levator scapulae

Answer 16

• O = transverse processes C1-4
• I = Medial border of scapula
• A = draws scapula superomedially, rotates glenoid cavity inferiorly, lateral neck flexion, neck extension

Question 17

Innervation of levator scapulae

Answer 17

• Anterior rami C3-4
• Dorsal scapular nerve (C5)

Question 18

Origin, insertion and action of rhomboid major

Answer 18

• O = spinous process T2-5
• I = medial border of scapula
• A = draws scapula superomedially, rotates glenoid cavity inferiorly, supports position of scapula

Question 19

Innervation of rhomboid major

Answer 19

Dorsal scapular nerve (C4-5)

Question 20

Origin, insertion and action of rhomboid minor

Answer 20

• O = nuchal ligament, spinous processes C7-T1
• I = medial end of spine of scapula
• A = draws scapula superomedially, rotates glenoid cavity inferiorly, supports position of scapula

Question 21

Innervation of rhomboid minor

Answer 21

Dorsal scapular nerve (C4-5)

Question 22

Intermediate extrinsic back muscles

Answer 22

• Serratus posterior superior
• Serratus posterior inferior

Question 23

Origin, insertion, action and innervation of serratus posterior superior

Answer 23

• O = nuchal ligament, spinous processes C7-T3
• Ins = superior border ribs 2-5
• A = elevates ribs
• Inn = 2-5 intercostal nerves

Question 24

Origin, insertion, action and innervation of serratus posterior inferior

Answer 24

• O = spinous processes T11-L2
• Ins = inferior border ribs 9-12
• A = depresses ribs
• Inn = anterior rami spinal nerve T9-12

Question 25

Boundaries of triangle of auscultation

Answer 25

- Inferior portion of trapezius (medial) - Latissimus dorsi (inferior) - Medial border of scapula (lateral) - Erector spinae (floor)

Question 26

3 groups of intrinsic back muscles

Answer 26

- Superficial - Deep - Deepest

Question 27

Superficial intrinsic back muscles

Answer 27

- Splenius (capitis, cervicis) - Erector spinae > Spinalis (capitis, cervicis, thoracis) > Longissimus (capitis, cervicis, thoracis) > Iliocostalis (cervicis, thoracis, lumborum)

Question 28

Deep intrinsic back muscles

Answer 28

- Transversospinales > Semispinalis (capitis, cervicis, thoracis) > Multifidus (cervicis, thoracis, lumborum) > Rotatores (breves, longi)

Question 29

Deepest intrinsic back muscles

Answer 29

- Interspinales (cervicis, thoracis, lumborum) - Intertransversarii (colli, lumborum)

Question 30

What are all intrinsic back muscles innervated by?

Answer 30

Posterior rami of spinal nerves

Question 31

Origin, insertion and action of the different parts of splenius

Answer 31

- Capitis > O = nuchal ligament, spinous processes C7-T3 > I = lateral superior nuchal line of occipital bone, mastoid process of temporal bone > A = extend head + neck, lateral flexion + rotation of head - Cervicis > O = spinous processes T3-6 > I = transverse processes C1-3 > A = lateral flexion + rotation of neck, extension of neck

Question 32

Origin, insertion and action of the different parts of spinalis

Answer 32

- Capitis > O = spinous processes C7-T1 > I = occipital bone - Cervicis > O = spinous processes C7-T1, nuchal ligament > I = spinous processes C2-4 - Thoracis > O = spinous processes T11-L2 > I = spinous processes T2-8 - Action of all = extension of head + cervical/thoracic spines, lateral flexion of cervical/thoracic spines

Question 33

Origin, insertion and action of the different parts of longissimus

Answer 33

- Capitis > O = transverse processes C4-T5 > I = mastoid process > Exclusive A = extension of head + neck, lateral flexion + rotation of head - Cervicis > O = transverse processes T1-5 > I = transverse processes C2-6 - Thoracis > Origin + Lumbar part = lumbar intermuscular aponeurosis, medial part of sacropelvic part of ilium, posterior sacroiliac ligament + Thoracic part = spinous + transverse processes of L1-5, median sacral crest, posterior surface of sacrum + posterior iliac crest > Insertion + Lumbar part = accessory + transverse processes L1-5 + Thoracic part = transverse processes T1-12, angles of ribs 7-12 - Action of all = extension of spine, lateral flexion of spine

Question 34

Origin, insertion and action of the different parts of iliocostalis

Answer 34

- Cervicis > O = angle of ribs 3-6 > I = transverse processes C4-6 - Thoracis > O = Angle of ribs 7-12 > I = Angle of ribs 1-6, transverse process C7 - Lumborum > O = lateral crest of sacrum, medial end of iliac crest, thoracolumbar fascia > I = Angle of ribs 5-12, transverse processes L1-4 - Action of all = extension of spine, lateral flexion of spine

Question 35

Origin, insertion and action of the different parts of semispinalis

Answer 35

- Capitis > O = articular processes C4-7, transverse processes T1-6 > I = between superior + inferior nuchal lines of occipital bone - Cervicis > O = transverse processes T1-6 > I = spinous processes C2-5 - Thoracis > O = transverse processes T6-10 > I = spinous processes C6-T4 - Action for all = extension/lateral flexion/rotation of head + cervical/thoracic spines

Question 36

Origin, insertion and action of the different parts of multifidus

Answer 36

- Cervicis > O = superior articular processes C4-7 > I = spinous processes 2-5 levels above origin - Thoracis > O = transverse process of thoracic vertebrae > I = spinous processes 2-5 levels above origin - Lumborum > O = mamillary processes of lumbar vertebrae, posterior aspect of sacrum, PSIS, posterior sacroiliac ligament > I = spinous processes 2-5 levels above origin - Action of all = extension, lateral flexion + rotation of spine

Question 37

Origin, insertion and action of the different parts of rotatores

Answer 37

- Breves > O = transverse processes T2-12 > I = laminae/spinous processes of vertebra 1 level above origin - Longi > O = transverse processes thoracic vertebrae > I = laminae/spinous processes of vertebra 2 levels above origin - Action of both = extension + rotation of thoracic spine

Question 38

Origin, insertion and action of the different parts of interspinales

Answer 38

- Cervicis > O = superior aspect of spinous processes C3-T1 > I = inferior aspect of spinous processes C2-7 - Thoracis > O = superior aspect of spinous processes T2, 11 + 12 > I = inferior aspect of spinous processes T1, 10 + 11 - Lumborum > O = superior aspect of spinous processes L2-5 > I = inferior aspect of spinous processes L1-4 - Action of all = extension of cervical + lumbar spine

Question 39

Origin, insertion and action of the different parts of intertransversarii

Answer 39

- Colli > O = transverse processes of cervical > I = transverse processes of adjacent vertebrae > A = assist in lateral flexion of + stabilise cervical spine - Lumborum > Origin + Lateral = transverse + accessory processes L1-4 + Medial = accessory processes L1-4 > Insertion + Lateral = transverse process of succeeding vertebra + Medial = mammillary process of succeeding vertebra > Action = assist lateral flexion of spine, stabilise spine