Lecture 7: Muscle/Joint Interaction of Cervical and Thoracic Spine Test 2

Question 1

Roles of cervicothoracic musculature

Answer 1

control posture
stabilize
protect SC/internal organs
generate intrathoracic pressure
furnish mobility/placement for head and neck

Question 2

features of cervicothoracic musculature

Answer 2

vary in length, fiber direction, shape, CSA, and leverage

muscles may cross many joints

Question 3

how are spinal nerve roots formed

Answer 3

formed by union of ventral and dorsal nerve roots

join near or within intervertebral foramen to form root

contain combinations of sensory and motor fibers

Question 4

describe ventral vs dorsal nerve roots

Answer 4

ventral = primarily efferent (outgoing) axons; motor

dorsal = afferent (incoming) dendrites with cell body in dorsal root ganglion (sensory)

Question 5

how many spinal nerves are there (and how many in each spinal segment)

Answer 5

31 pairs

8 cervical, 12 thoracic, 5 lumbar, 5 sacral, 1 coccygeal

Question 6

where do the 1st and 8th cervical nerve roots exit

Answer 6

1st is between occipital bone and posterior arch of C1

8th is between C7 and T1

Question 7

where do all of the nerve roots below the cervical spine exit

Answer 7

all below the cervical region exit inferior to their respective vertebtral bodies

Question 8

describe what happens to the spinal nerves when they exit the spine

Answer 8

split into dorsal and ventral ramus

ventral forms nerves that innervate muscles, joints, and skin of anterior lateral trunk and neck and the extremities

dorsal forms nerves that innervate muscles, joints, and skin of posterior trunk and neck

Question 9

what do the intercostal nerves innervate

Answer 9

muscles in the anterior lateral trunk such as the intercostal and abdominal muscles

branching from ventral ramus

Question 10

name some examples of what the dorsal ramus innervates

Answer 10

trunk and extensor muscles such as erector spinal or multifidi

Question 11

sensory fibers of ventral and dorsal rami can innervate what

Answer 11

ligaments and other connective tissues

Question 12

what is a plexus

Answer 12

intermingling of ventral rami

form peripheral nerves (i.e. the radial)

Question 13

what are the 2 most common plexuses and where do they innervate generally

Answer 13

cervical (C1-C4) and brachial (C5-T1)

cervical goes mostly to axial skeleton and brachial goes mainly to UEs

Question 14

what do each of the 12 ventral rami of the thoracic region innervate

Answer 14

each of the 12 form intercostal nerves that innervate both an intercostal muscle and an intercostal dermatome in the same place

**T1 contributes to the brachial plexus and the 1st intercostal nerve

Question 15

describe recurrent meningeal nerves

Answer 15

a single recurrent meningeal nerve branches off proximally

sensory/sympathetic supply to the meninges (at the spinal cord) and connective tissue to the intervertebral joints (PLL and ALL)

Question 16

describe how a recurrent meningeal nerve supplies in the vertebral canal

Answer 16

branch of spinal nerve passes in recurrent fashion back through the vertebral foramen

this supplies many areas including the outer 1/3 of the annular fibers of the disc

nerve fibers are sensory and carry signals to the brain when the tissue is damages

Question 17

describe the dorsal rami spinal roots compared to the ventral

Answer 17

from C3 and below they are smaller than the ventral counterparts

Question 18

what is the dorsal rami of C1 (motor vs sensory?)

Answer 18

“suboccipital nerve”

primarily motor

innervates sub occipital muscles

Question 19

describe C2 dorsal rami

Answer 19

largest dorsal rami

innervates local muscles

contributes to greater occipital nerve which is C2 and C3 (sensory to scalp region)

Question 20

what specific muscles are innervated by the sub occipital nerve

Answer 20

rectus capitis posterior minor and major

obliquus capitis superior

Question 21

type of innervation of greater occipital nerve

Answer 21

sensory

Question 22

what is the third occipital nerve

Answer 22

(TON) is a branch of the posterior root of C3

provides cutaneous sensation to a small portion of the occipital scalp and innervates the C2/3 facet joints

Question 23

what is the greater occipital nerve

Answer 23

GON

main sensory nerve to the occipital area

associated with various pain syndromes such as occipital neuralgia, cervicogenic headaches, and migraine

Question 24

what is bilateral activation/what does it produce

Answer 24

usually produces pure flexion or extension of axial skeleton

any potential for lateral flexion or axial rotation is neutralized by opposing forces in contralateral muscles

Question 25

what is unilateral activation/what does it produce

Answer 25

tends to produce flexion and extension of the axial skeleton with some combo of lateral flexion and contralateral or ipsilateral axial rotation

Question 26

the action of a muscle in the axial skeleton depends on what

Answer 26

the degree of fixation/stabilization of the attachments of the muscle

Question 27

describe how gravity affects flexion of the neck

Answer 27

slow/moderate flexion gravity is the main flexor (extensor muscles act eccentrically to control movement and speed)

rapid flexion activates the neck flexors

Question 28

superficial muscle layer of the back

Answer 28

trapezius
latissimus dorsi
rhomboids
levator scapulae
serratus anterior

Question 29

muscles in intermediate layer of back

Answer 29

serratus posterior superior and inferior

Question 30

Deep layer of the back (from most superficial to deep)

Answer 30

erector spinae
transversospinal
short segment

Question 31

what are the erector spinal muscles lateral to medial

Answer 31

illiocostalis (thoracic and cervicis)
Longissumus (thoracis, cervicis, and capitis)
spinalis (thoracis, cervicis, and capitis)

Question 32

what is the fiber direction of longissimus cervicis and capitis

Answer 32

cervicis = cranial and medial

capitis = cranial and lateral

Question 33

what is the fiber direction of the illiocostalis cervicis

Answer 33

vertical and medial

Question 34

what muscles make up the transversospinal

Answer 34

semispinalis thoracis
semispinalis cervicis
semispinalis capitis
multifidi
rotatores

Question 35

what muscles make up the short segment of the back

Answer 35

interspinalis
intertransversarius

Question 36

what are the muscles that fall into the anterior lateral craniocervical region (and what are they innervated by)

Answer 36

SCM
scalenes
longus colli
longus capties
rectus capitis anterior
rectus capitis lateralis

** all but SCM are innervated by small, unnamed nerves branching firm the ventral rami of the cervical plexus

Question 37

what are the 2 heads of the SCM

Answer 37

sternal and clavicular

Question 38

what are the actions of the SCM

Answer 38

primary (mid/lower cervical spine) = lateral flexor, contralateral rotation, bilateral flexion

above C3 acts as a small extensor torque

Question 39

innervation of SCM

Answer 39

accessory nerve (CN 11)

Question 40

function of anterior and middle scalenes

Answer 40

lift first rib

laterally flex cervical spine ipsilaterally (anterior has best moment arm)

Question 41

posterior scalene function

Answer 41

lifts 2nd rib

laterally flexes cervical spine ipsilaterally

Question 42

innervation of scalenes

Answer 42

anterior and middle = C4-C6 spinal nerves

posterior = C6-C8

Question 43

anterior and middle scalene attachments

Answer 43

from anterior tubercles of C3-C6 TP (anterior) and C2-C7 TP (middle)

attaches to scalene tubercle on inner border of 1st rib

Question 44

posterior scalene attachments

Answer 44

posterior tubercles of TP of C5-C7

attaches to 2nd rib

Question 45

which scalene is smallest/deepest

Answer 45

posterior

Question 46

where does the brachial plexus run in relation to the scalenes

Answer 46

between anterior and middle scalene

Question 47

main roles of scalenes

Answer 47

stability to lower and middle C/spine and ventilation

Question 48

where are longus Colli and longus capitis (generally) and what is their collective function

Answer 48

deep to trachea and esophagus

function as a dynamic ALL (vertical stability)

Question 49

where is longus colli and what is its specific function

Answer 49

anterior to T1-3 and all cervical vertebrae bodies, TPs, and anterior arch of atlas

can flex and reduce cervical lordosis

Question 50

where is longus capitis specifically and what is its function

Answer 50

mid/lower TPs into the basilar part of the occiput

flexes and stabilizes the upper craniocervical spine

Question 51

innervation of longus colli and longus capitis

Answer 51

anterior rami C2-6

Question 52

what are the attachments for rectus capitis anterior and rectus capitis lateralis

Answer 52

short deep muscles

arise form C1 TPs

insert on inferior surface of occipital bone (lateral and anterior to the condyles)

Question 53

actions of rectus capitis anterior and lateralis

Answer 53

acts on OA joint

anterior = flexion

lateralis = lateral flexion

Question 54

where do the splenius muscles attach

Answer 54

cervicis and capitis both arise from inferior half of ligamentum nuchae/spinous processes of C7-T6

capitis attaches to occipital bone

cervicis attaches to posterior tubercles of TPs of C1-C3 (shared with levator scapulae)

Question 55

function of the splenius muscles

Answer 55

unilateral contraction = lateral flexion and ipsilateral rotation

bilateral contraction = extends upper craniocervical region

Question 56

what are the 4 sub occipital muscles

Answer 56

rectus capitis posterior major/minor

obliquus capitis inferior/superior

Question 57

describe the sub occipital muscles

Answer 57

very deep; immediately superficial to OA/AA

deep to upper trap, splenius, semispinalis capitis

attach to atlas, axis, and occipital bone

provide precise control over OA/AA

large # of muscle spindles that give neural feedback and allow hand eye coordination and balance

Question 58

posterior and lateral neck musculature serves to do what

Answer 58

protect cervical viscera, blood vessels, discs, facet joints, and neural tissues

Question 59

for stability, muscular needs to be trained to do what

Answer 59

contract before the “load”

Question 60

describe the loads on the craniovertebral region during function

Answer 60

the head weighs 3x its normal weight with low-level upright standing/balancing head

with max muscle effort, the neck muscles can generate force 23x the normal weight of the head

require short stabilizing muscles and long guide wire muscles

Question 62

what is ideal for neck stability

Answer 62

co-contractions of flexors and extensors

cervical muscles are anchored to other structures (i.e. sternum, clavicle, ribs, scapula, and vertebrae) that must be stabilized themselves as well