Foundational Sciences: Spinal Functional Anatomy & Tmj Functional Anatomy

Front 1

how many bones are in the vertebral column?

Back 1

33 bones

Front 2

What are the normal physiological curves of the spine?

Back 2

sacral convex posteriorly

lumbar concave posteriorly

thoracic convex posteriorly

cervical concave posteriorly

Front 3

what is kyphosis?

Back 3

excessive posterior curvature of thoracic spine

Front 4

what is scoliosis and most common area for it to occur?

Back 4

lateral curvature of the spine

-most often in thoracic spine

Front 5

What is lordosis?

Back 5

increased anterior curvature most often in lumbar spine

Front 6

What parts of the vertebra make up the vertebral arch?

Back 6

pedicles and laminae

Front 7

where are the lamina in comparison to the pedicles?

Back 7

lamina are more posterior than pedicles

Front 8

what do the laminae form?

Back 8

laminae on each vertebra meet to form the spinous process

(mnemonic: Lamina Like each other so they combine to form SP)

Front 9

What do the pedicles join?

Back 9

pedicles join the vertebral body to the transverse process

Front 10

what are the other parts of each vertebra (other than pedicles and laminae)

Back 10

2 transverse processes

4 articular processes

Front 11

what forms the vertebral canal? and what is in the canal?

Back 11

the arches of successive vertebrae form the vertebral canal

-contains spinal cord

Front 12

what is the intervertebral foramen

Back 12

lateral opening formed by the stacking of vertebra through which spinal nerve roots exit from the SC

Front 13

what is a regional characteristic unique to cervical vertebrae?

Back 13

(7) cervical

-foramina of transverse process contain vertebral arteries

-C1 has no spinous process

Front 14

what is a regional characteristic unique to thoracic vertebra?

Back 14

(12) thoracic

facets on vertebral bodies for articulation with the ribs

Front 15

what is a regional characteristic unique to lumbar vertbrae?

Back 15

(5) Lumbar

massive bodies and sturdy laminae to support weight of the body

Front 16

what is a regional characteristic unique to sacral vertebrae?

Back 16

5 sacral

-fused vertebrae with 4 foramina on each side

Front 17

what is a regional characteristic unique to coccyx?

Back 17

tiny incomplete (no vertebral arch) and 4 fused vertebrae

Front 18

which cervical vertebra are easily palpated?

Back 18

C3-C5 are short and deep to the surface = difficult to palpate

C7: vertebra prominens and easy to palpate

Front 19

where can transverse processes be palpated?

Back 19

in thoracic and lumbar region

Front 20

what type of lever do the intervertebral joint form?

Back 20

each segment forms a first class lever system

facets = fulcrum

paraspinals = force component

weight of upper body and head = resistance component

Front 21

what is a spinal/vertebral segment?

Back 21

two adjacent vertabrae with the disc in between

Front 22

How does the size of the vertebral bodies change as you move inferiorly down column?

Back 22

from T4 inferiorly vertebral bodies become progressively larger to bear incr weight

Front 23

what types of fractures can occur in the vertebral bodies?

Back 23

wedge fracture

burst fracture

tear drop fracture

Front 24

what is a vertebral wedge fracture and MOI?

Back 24

compression of anterior aspect of vertebral body from forced flexion of the thoracic or lumbar spine

Front 25

what is the MOI of a burst vertebral body fracture?

Back 25

excessive compression of the vertebral body

Front 26

what is a teardrop vertebral body fracture?

Back 26

compression of anterior vertebral body causing a triangular fragment to split from body anteriorly

Front 27

what is the structure of the intervertebral disk?

Back 27

2 portions

inner portion= nucleus pulposus

-mostly water and is maintained in central position by the annular rings that are firmly attached superiorly and inferiorly to adjacent vertebral bodies

outer structure = annulus fibrosis = layers of concentric fibers

Front 28

what is the function of the IV disc?

Back 28

it is flexible

-shock absorption to dissipate compressive load

Front 29

when is the IV disc at risk of injury?

Back 29

during trunk rotation, IV pressure increases and annular fibers oriented in direction of the rotatory movement become taut

-rotation with compressive forces (e.g. while under a load from lifting) increases risk of injury

Front 30

What injury can occur to the IV disc?

Back 30

rotation with compressive force can cause herniated or protruding nucleus pulposus

-usually occurs posterolaterally and may compress an adjacent spinal nerve root

Front 31

What type of joint are the zygapophyseal joints?

Back 31

aka facet joints

plane synovial joints between inferior and superior articular processes of adjacent vertebra

Front 32

What covers the joint surfaces of the facets and what surrounds each facet joint?

Back 32

hyaline cartilage covers the flat surface of each facet

-each facet joint is surrounded by a thin, loose articular capsule

Front 33

what is the function of the facet joints?

Back 33

-permit gliding between the vertebrae

-in cervical and lumbar regions, facet joints bear some weight

-help to control flexion, ext, and rotation of adjacent vertebrae

Front 34

Where does the majority of the vertebral column movement take place?

Back 34

in cervical and lumbar regions

Front 35

when can the facet joints become injured and what can result?

Back 35

quick flexion and rotation movement can cause impingement of the articular capsule

-disease such as osteoarthritis

-with injury to facet joints, the related spinal nerves are often affected

-this can cause pain and mm spasm along related dermatomes &/or myotomes.

Front 36

what ligaments lie between the spinous processes of adjacent vertebrae?

Back 36

supraspinous ligament and interspinous ligament

Front 37

where does the ligamenta flava lie?

Back 37

connects laminae of adjacent vertebral arches

Front 38

where is the posterior longitudinal ligament?

Back 38

along posterior aspect of the vertebral bodies and lies in the vertebral canal

Front 39

where is the anterior longitudinal ligament?

Back 39

connects anterior aspects of the vertebral bodies and intervertebral discs

Front 40

what does the ALL and PLL prevent?

Back 40

ALL (broader than PLL) prevents hyperextension and supports the intervertebral discs

-PLL (narrower and weaker than ALL) prevents hyperflexion and posterior protrusion of the nucleus pulposus

Front 41

what do the iliolumbar ligaments connect?

Back 41

2 bands

superior band runs from L4 TP to iliac crest

inferior band runs from L5 TP to iliac crest, anterior surface of SI joint and lateral sacral ala

Front 42

what is the function of the iliolumbar ligaments?

Back 42

provide structural support to the lower lumbar spine

-connect sacrum and ilium to the lumbar spine

Front 43

what is the implication of the iliolumbar ligaments to dysfunction and LBP?

Back 43

dysfunction of the SI joint may influence structure and function of the L4 and L5 vertebra

Front 44

what are the 3 groups of back muscles?

Back 44

superificial

intermediate

deep

superficial and intermediate are considered the extrinsic muscles

deep = intrinsic muscles

Front 45

what is the function of the superficial back muscles?

Back 45

connect the upper limb to the trunk and provide movement of the limbs (e.g. trapezius and latissimus dorsi)

Front 46

what is the function of the intermediate back muscles?

Back 46

=respiratory muscles (e.g. serratus posterior)

Front 47

what is the overall function of the intrinsic back muscles?

Back 47

the deep muscles (e.g. erector spinae) maintain posture and move the vertebral column and head

Front 48

What are the 3 layers of the intrinsic back muscles?

Back 48

superficial layer, intermediate layer, deep layer

Front 49

what muscles are in the superficial layer of the intrinsic back muscles?

Back 49

splenius muscle (capitis and cervicis)

-acting alone = laterally flex and rotate head and neck to same side

-together = extend head and neck

Front 50

what muscles are in the intermediate layer of the intrinsic back muscles?

Back 50

erector spinae in 3 vertical columns:

iliocostalis (lateral)

longissimus

spinalis (medial)

Action:

bilat: extend head and vertebral column

unilaterally: lateral flexion of head and vertebral column

-concentrically straighten the flexed spine and eccentrically allow vertebral column to bend forward

Front 51

what is a back strain?

Back 51

results from extreme movements usually flexion and rotation of the vertebral column

-some degree of stretching or microscopic tearing of muscle and/or ligament fibers

-usually erector spinae are involved

Front 52

what muscles are in the deep layer of the intrinsic back muscles?

Back 52

semispinalis

multifidus

rotatores muscle

collectively these = transversospinal muscles bc fibers attach between tranverse processes and spinous processes of the vertebrae

Action:

bilaterally: extend and stabilize spine

unilat: lateral flexion to same side and rotate trunk to opposite side

Front 53

what is the function of the quadratus lumborum?

Back 53

lumbar spine stabilizer

unilateral: elevates ilium

bilat: assists in forced exhalation and extends back

Front 54

what is the iliopsoas action and when is it active?

Back 54

iliacus + psoas muscles that share common insertion and action

Action: hip flexion and IR

active during walking, sitting, and standing

Front 55

what other action besides hip flexion and IR can the psoas assist in?

Back 55

lumbar extension

plays significant role in maintaining upright stance

Front 56

What are the actions/functions of the piriformis?

Back 56

when hip is extended and in nonweightbearing: hip ER

-when hip flexed at 90 deg: hip abd

-in weightbearing, piriformis resists hip IR

Front 57

What can muscle spasm of the piriformis cause?

Back 57

-mm spasm can put pressure on the sciatic nn and cause piriformis syndrome

-diskogenic radicular symptoms are common

Front 58

what level is the thyroid cartilage located at?

Back 58

C4-C5

Front 59

what vertebral level are the vocal cords located at?

Back 59

at the level with the midpoint of the anterior border of the thyroid cartilage (C4-C5)

Front 60

where does the hyoid bone lie?

Back 60

superior to the thyroid cartilage at C3 level

Front 61

what are the superificial neck muscles?

Back 61

platysma, SCM and Trapezius

Front 62

what is the function/action of the platysma?

Back 62

-tenses the skin of the neck

-assists in depressing the mandible

-draws the mouth inferiorly

-one of the facial expression muscles

Front 63

what is the function/action of the SCM?

Back 63

unilaterally: tilts the head to the same side and rotates the face in opposite direction

bilat: flexes the neck (e.g. when raising the head off a pillow)

Front 64

what is one injury of the SCM?

Back 64

at birth the muscle can be injured causing congenital torticollis or wryneck

Front 65

what action does the trapezius have?

Back 65

unilat: lateral flexion of the neck to the same side

bilat: shrugs the shoulders when the neck is stabilized

Front 66

what is an injury of the trapezius?

Back 66

forced forward flexion of the cervical spine (e.g. when in a head-on car collision) may cause strain and associated muscle spasms of the mm fibers in the trapezius

Front 67

where does the external carotid artery lie?

Back 67

in a groove created by the trachea and the strap muscles

Front 68

what does absence of a cartoid pulse indicate?

Back 68

cardiac arrest. and is a medical emergency

Front 69

where do the vertebral arteries originate? and what is their pathway?

Back 69

branch off the subclavian artery and ascends vertically through transverse foramina of the cervical vertebrae into the brain at the level of the foramen magnum

Front 70

what can occlusion of the vertebral arteries do?

Back 70

cause Vertebral artery syndrome

Front 71

what is Vertebral Artery Syndrome?

Back 71

occlusion or stenosis of the vertebral arteries can result in dizziness, tinnitus, fainting, nystagmus, and transient diplopia

Front 72

what are the bony landmarks of the TMJ?

Back 72

temporal bone forms the roof of the TMJ

from posterior to anterior landmarks are mandibular fossa, articular eminence, articular crest, articular tubercle

Front 73

What are the articulating surfaces of the TMJ?

Back 73

articular eminence-crest-tubercle area is the primary articulating surface of the temporal bone that articulates with the mandibular condyle of the mandible w

Front 74

what lies in the mandibular fossa at rest and with teeth in occlusion (closed)?

Back 74

posterior band of the disk occupies mandibular fossa

Front 75

Describe the anatomical bony landmarks of the mandible?

Back 75

-mandibular condyle is convex (varies in shape and size from person to person)

-landmarks on either side = medial and lateral poles

-neck = inferior to condylar head

-coronoid process = anterior to the neck and anterior to mandibular notch

-ramus = inferior to neck; starts the body of the mandible

-mandibular body = houses the lower arch of the teeth

Front 76

what are the articulating surfaces of the TMJ covered by?

Back 76

dense fibrous connective tissue that is avascular and aneural

-has greater potential to remodel and less likely to breakdown over time than hyaline cartilage.

Front 77

how is the TMJ unlike any joint in the body?

Back 77

end range is unique because rigid end point of closure created by lower arch of the teeth contacting the upper arch

Front 78

what detemines the final end point of the TMJ articulation?

Back 78

the occlusion determines the final end point of the condyle to disc to temporal bone relationship when the posterior teeth are together

Front 79

When can TMJ be injured?

Back 79

-improper closure of mandible may cause microtrauma and strain joint structures

-disc may displace anteriorly and medially

-variation in bony and muscular anatomy may affect loading of the articular surfaces

Front 80

where can TMJ be palpated?

Back 80

lateral pole of the mandibular condyle can be palpated anterior to external auditory meatus of the ear esp when opening and closing the mouth

Front 81

what is the composition of the articular disc of the TMJ? and the blood supply and neural supply?

Back 81

dense fibrous connective tissue

avascular

aneural

Front 82

Which bone is the TMJ disc more firmly attached to?

Back 82

more firmly attached to mandible than to temporal bone

Front 83

how does the disc move with the moving TMJ?

Back 83

when head of mandible slides anteriorly on the articular tubercle as the mouth opens, the articular disc slides anterior agains the posterior surface of the tubercle

Front 84

what medial/lateral attachments does the TMJ disc have?

Back 84

attaches to the medial and lateral poles of the condyle by the medial and lateral collateral ligaments

Front 85

What is the TMJ disc attachments posteriorly?

Back 85

-disc is continuous with posterior attachment which consists of bilaminar zone and retrodiscal pad

-bilaminar zone = superior and inferior lamina with the retrodiscal pad in between

-superior lamina: fibroelastic tissue with high elastin content

-attaches posteriorly to the tympanic plate

-passive tension applied when band is stretched to assist in returning disk to normal postion when disk is forward (during closing of the mouth)

-inferior lamina: mainly collagneous fibers with little elastic tissue

-attaches to neck of condyle

-limits forward motion of disk

-retrodiscal pad: loose connective tissue rich in arterial and neural supply

Front 86

what are the anterior attachments of the TMJ disc?

Back 86

joint capsule and superior lateral pterygoid muscle

-joint capsule limits posterior movement of disk

-superior 1/3 of superior lateral pterygoid attach to anterior and medial disc

-remaining fibers of superior lat. pterygoid and all of fibers of inferior lat. pterygoid attach to medial 1/3 of the neck of the condyle

Front 87

what is the function of the anterior attachment of the TMJ disc?

Back 87

Lat. pterygoid muscle actively assists in controlling posterior movement of disk during mouth closing through eccentric contraction

Front 88

what normally prevents anterior displacement of the disc in relation to the mandibular condyle?

Back 88

-disc has a biconcave shape creating "self-seating" effect

-tight medial and lateral collateral ligaments

-together these prevent anterior displacement

Front 89

what does the TMJ joint capsule attach to?

Back 89

attaches to the margins of the articular area on the temporal bone and around the neck of the mandible

Front 90

what is located in the TMJ joint capsule?

Back 90

-highly vascular, synovival producing membrane that supplies nutrients to nonvascularized tissues within the capsule

-articular mechanicoreceptors for kinesthetic and perceptional awareness of the mandible are located inside capsule

Front 91

What other ligaments besides the medial and lateral collateral ligaments are found around the TMJ?

Back 91

Temporomandibular ligament (TM)

stylomandibular ligament

sphenomandibular ligament

Front 92

what is the function of the temporomandibular ligament?

Back 92

-allows 20-25 mm of mandibular opening before it becomes tight

-after 25 mm, the condyle translates anteriorly to allow further opening

-i.e. max of 20-25 mm of opening occurs with rotation and no translation of the condyle

Front 93

Describe a possible injury of the TMJ?

Back 93

TMJ dislocation anteriorly during yawning or large bites

-contraction of lateral pterygoid may cause head of mandible to dislocate or pass anterior to articular tubercle-->mandible remains open and person cannot close it

Front 94

what type of joint is the TMJ and what movements occur at the joint?

Back 94

modified hinge synovival joint with 2 arthrokinematic movements

1). anterior gliding

2). hinge-like rotation

Osteokinematic movements:

1). elevation/depression

2). protrusion/retrusion

3). lateral deviation

Front 95

What are the arthrokinematics that occur during mandibular depression?

Back 95

2 phases

1). rotation of condyle around long axis of the condylar heads during 1st 10-15 mm

2). head of mandible and articular disc glide anteriorly until head lies inferior to articular tubercle

Front 96

what motions does functional TMJ/mouth opening combine? and how much is this?

Back 96

combines rotation and translation and is ~40 mm (3 knuckles)

Front 97

what is TMJ protrusion?

Back 97

anterior translation in the horizontal plane and involves bilateral anterior condylar translation

Front 98

what is TMJ lateral excursion?

Back 98

mandible moves laterally in the horizontal plane

-involves anterior translation on the contralateral side and spin on the ipsilateral side.

(e.g. right lateral deviation/excursion [jaw moves toward the right side] = right condyle rotates and left translates anteriorly)

Front 99

what muscles are involved in elevating the mandible?

Back 99

masseter

temporalis

medial pterygoid

Front 100

what muscles protrude the mandible?

Back 100

lateral and medial pterygoid

Front 101

what muscles retrude the mandible?

Back 101

posterior fibers of temporalis

Front 102

what muscles depress the mandible?

Back 102

primarily occurs by gravity

Front 103

what muscles act to lateral deviate the TMJ/mandible?

Back 103

ipsilateral to side of movement = temporalis and masseter

contralateral to side of movement = medial and lateral pterygoid