Lecture 5: Vertebral Column 2

Question 1

What is the role of extrinsic muscles?

Answer 1

produce upper limb and respiratory movements

Question 2

What is the role of intrinsic muscles?

Answer 2

produce vertebral column movements and maintain posture

Question 3

What are the most important things to know about a muscle?

Answer 3

muscle name, proximal attachment, distal attachment, function (i.e. contraction type: concentric vs eccentric), action, functional role and innervation

Question 4

What are the functional roles of muscles?

Answer 4

agonist, antagonist, fixator/stabiliser, synergist and assistant muscle

Question 5

How does the length of a muscle change during concentric and eccentric contractions?

Answer 5

concentric: shortens
eccentric: lengthens

Question 6

What are the three groups intrinsic back muscles are divided into?

Answer 6

erector spinae, transversospinalis (oblique orientation from inferior transverse process to superior spinous process) and uni-segmental group

Question 7

What are the three subgroups of erector spinae and what are the subgroups of these subgroups? What are their actions?

Answer 7

spinalis: spinalis thoracis, cerivicis and capitis -> extends trunk (concentric)
longissimus: longissimus thoracis, cervicis and capitis -> extends trunk, head and neck
iliocostalis: iliocostalis lumborum, thoracis and cervicis -> extends and ipsilaterally laterally flexes trunk and neck

Question 8

What are the three subgroups of transversospinalis and what are the subgroups of these subgroups? What are their actions?

Answer 8

semispinalis: semispinalis thoracis, cervicis and capitis -> extends and contralaterally rotates the trunk, neck and head
multifidus: extends, contralaterally rotates and ipsilaterally laterally flexes trunk and neck
rotatores

Question 9

Which muscles constitute the uni-segmental group?

Answer 9

intertransversarii, interspinales and levatores costarum

Question 10

What are the functional roles of intrinsic muscle?

Answer 10

head, neck and trunk movements
stabilisation of trunk during limb movement
provide proprioceptive feedback
protect zygapophyseal joints

Question 11

How do extensors of the neck and/or head contract?

Answer 11

concentrically contract to produce extension

Question 12

Which muscles are found in the deepest layer (layer 4) of neck/head extensors?

Answer 12

suboccipital muscles (x4)
transversospinalis (x2) - rotatores and multifidis

Question 13

Which muscles are found in layer 3 of neck/head extensors?

Answer 13

capitis and cervicis

Question 14

Which muscles are found in layer 2 of neck/head extensors?

Answer 14

splenius capitis and cervicis
erector spinae - longissimus capitus/cervicus, spinalis capitus/cervices, iliocostalis cervices
levator scapulae

Question 15

Which muscles are found in layer 1 of neck/head extensors?

Answer 15

trapezius

Question 16

How do flexors of the neck and/or head contract?

Answer 16

concentrically contract to produce flexion

Question 17

Which muscles are flexors of the neck/head?

Answer 17

SCM
longus capitis and colli
rectus capitis lateralis and rectus capitis anterior
scalene muscles

Question 18

What is the role of lateral flexors of the neck/head?

Answer 18

produce lateral flexion when contracting unilaterally

Question 19

What are the rotators of the neck and head on the ipsilateral side?

Answer 19

splenius cervicis and capitis, rectus capitis posterior major, inferior capitis oblique and longissimus cervicis and capitis

Question 20

What are the rotators of the neck and head on the contralateral side?

Answer 20

SCM, anterior scalene, multifidus, semispinalis and longus colli

Question 21

What is the role of thoracolumbar fascia?

Answer 21

provides lumbar stability and acts as retinaculum around deep back muscles
also provides connection between vertebral column, abdominal muscles, upper and lower limbs

Question 22

What is the role of intraabdominal pressure?

Answer 22

helps stiffen the lumbar spine to prevent buckling under compressive loads

Question 23

Which arteries are part of the vertebral vasculature?

Answer 23

anterior / posterior spinal arteries, vertebral artery, subclavian artery, posterior intercostal artery, lumbar artery and segmental medullary artery, anterior / posterior radicular arteries

Question 24

How does venous drainage occur in the vertebrae?

Answer 24

intervertebral veins drain into vertebral, posterior intercostal and lumbar veins, which drain into the IVC or SVC
note: posterior intercostal veins drain into the azygous system then the SVC

Question 25

How are the back muscles innervated?

Answer 25

ventral rami supply extrinsic back muscles

dorsal rami supply intrinsic back muscles

Question 26

Which branches are the dorsal rami divided into? Which structures do these branches innervate?

Answer 26

lateral branch:
iliocostalis and longissimus
medial branch:
spinalis, transversospinalis and unisegmental muscles
zygapophyseal joints
overlying skin

Question 27

Where are nerves in the cervical plexus found? Which type of branches are found in the cervical plexus?

Answer 27

C1-4 ventral rami

there are superficial and deep branches