Lecture 3 back (pt 2)

Question 1

1) What two things are IV discs associated with?
2) What is the more exterior part of the IV discs called? Where does it attach?
3) What is the more interior part of the IV discs called? Where is it located?

Answer 1

1) ROM and natural curvatures of spine
2) Annulus fibrosus (85% water); attaches to end plates
3) Nucleus pulposis; positioned more posteriorly

Question 2

Describe the shape of annulus fibrosus

Answer 2

Thinner posteriorly (why herniated discs can happen)

Question 3

What is the nucleus pulposis of an IV disc made of?

Answer 3

85% water initially, desiccate with age

Question 4

1) Where is there no IV disc?
2) What is the most inferior functional IV disc?

Answer 4

1) C1-2
2) L5-S1

Question 5

1) Define annuli
2) How do the fibers of each lamellae run?

Answer 5

1) Annulus fibrosus; concentric rings (lamellae) of connective tissue that insert into smooth end plates of the vertebral body
2) From one body to adjacent body, typically at right angles to adjacent lamellae

Question 6

1) Describe IV disc protrusion
2) Why can this happen?

Answer 6

1) IV nucleus pulposus protrudes backwards towards the cauda equina due to a defect in the anulus fibrosis (in lumbar vertebrae)
2) Annulus fibrosis thinner posteriorly, can slip backwards when back is hyperextended (like in gymnastics)

Question 7

List the 6 ligaments of the spinal column

Answer 7

1) Anterior longitudinal
2) Posterior longitudinal
3) Ligamentum flavum
4) Interspinous ligament
5) Nuchal ligament (in nuchal groove)
6) Supraspinous ligament

Question 8

1) What merges with the nuchal ligament?
2) Describe the nuchal ligament’s location

Answer 8

1) Supraspinous ligament merges
2) Ext occipital prominence & posterior margin of foramen magnum to spinous process of C-Vertebrae

Question 9

List the 5 types of joints found in the vertebral column

Answer 9

1) Vertebral bodies: IV Discs, uncovertebral joints
2) Vertebral arches: Zygapophysial (facet) joints
3) Craniovertebral: occipital condyle with atlas
4) Costovertebral: ribs
5) Sacroiliac: SI joint

Question 10

1) Describe the joints of the vertebral arches; what type of joints are they?
2) What do they allow for?
3) What are they innervated by?

Answer 10

1) Zygapophysial (facet) joints; synovial
2) Gliding movement
3) Medial branch of posterior rami spinal nerves

Question 11

What are the 3 branches of the median branch of the posterior rami of spinal nerves?

Answer 11

Muscular, cutaneous and articular branches

Question 12

1) What are the 4 movements of the spine?
2) What reduces these movements in some people?
3) Why?
4) What innately limits movement?

Answer 12

1) Flexion, extension, lateral flex, rotation
2) Age
3) Primarily from IV-disc compression and elasticity
4) Physical characteristics of the anatomy

Question 13

Is age the primary cause of reduced spinal movement? Explain

Answer 13

No, it’s secondary to degenerative changes in IV disc and other structures

Question 14

What 3 things allow movement of the spine?

Answer 14

1) Back and abdominal muscles (like rectus abdominus and obliques)
2) Gravity
3) Movement between adjacent vertebra (Zygapophyseal joints and IV-disc)

Question 15

What are the two types things that allow movement between adjacent vertebrae?

Answer 15

Zygapophyseal joints and IV-disc

Question 16

What part of the spine has the greatest degree of flexion ROM?

Answer 16

Cervical spine

Question 17

What 4 joints allow you to look back over your shoulder? (like checking blind spot while driving)

Answer 17

1) Cranio-atlas rotation (minimal)
2) Atlanto-axial joints (C1-2)
3) Cervical rotation
4) Rotation of upper trunk or thoracic spine

Question 18

What two things limit ROM of the thoracic spine?

Answer 18

Ribs and sternum

Question 19

1) What allows for greater flexion and extension of the lumbar spine?
2) Is there a lot of rotation of the lumbar spine? Why?
3) Describe the IV discs of the lumbar spine

Answer 19

1) Facet joints
2) Minimal rotation due to interlocking facets
3) Relatively large IV discs

Question 20

Is extension or flexion greater in the lumbar area?

Answer 20

1) Extension > flexion
(spondylosis in gymnast)

Question 21

Where does most of flexion occur when you bend forward and touch your toes?

Answer 21

Mostly in the hips

Question 22

Describe the vascular supply of the vertebral column; what are the 5 sources? Describe each

Answer 22

1) Vertebral: comes several branches of aortic arch
2) Ascending cervical: help outside vertebral foramen
3) Deep cervical: help outside vertebral foramen
4) Intercostal: for thoracic (comes off aorta)
5) Lumbar or sacral (comes off aorta)

Question 23

What are the 3 longitudinal arteries that supply the vertebral column?

Answer 23

1) Anterior spinal artery
2&3) Paired posterior spinal arteries

Question 24

Describe venous drainage of the vertebral column

Answer 24

-Forms venous plexuses:
1) External plexus
2) Internal plexus

Question 25

Describe the manner in which the venous plexuses that drain the spine communicate

Answer 25

Communicate freely

Question 26

1) Where is the internal vertebral venous plexus?
2) Where does it drain?
3) What does it communicate with?

Answer 26

1) In epidural space
2) Drains superiorly into dural venous sinus in cranium
3) With external vertebral plexus on external surface of vertebra

Question 27

What innervates the vertebral column?

Answer 27

Meningeal branches of spinal nerves

Question 28

1) Where is most body weight in relation to the vertebral column?
2) Where is most muscle support in relation to the vertebral column?
3) What are the two types of back muscles?

Answer 28

1) Anterior
2) Posterior
3) Intrinsic and extrinsic

Question 29

What are the two types of extrinsic back muscles? What does each do?

Answer 29

1) Superficial: control limb movement
2) Intermediate: control respiratory movement

Question 30

What are the 3 kinds of intrinsic back muscles? (bonus: give examples of each)

Answer 30

1) Superficial: splenius
2) Intermediate: erector spinae
3) Deep: transversospinalis

Question 31

1) Give 4 examples of superficial [extrinsic] back muscles
2) How are they innervated?
3) What do they act on?

Answer 31

1) Trapezius, latissimus dorse, levator scapulae, & rhomboids (all bilateral)
2) Anterior rami or CN XI
3) UE (upper extremities)

Question 32

Give 2 examples of intermediate [extrinsic] back muscles

Answer 32

1) Serratus posterior, superior, and inferior
2) Proprioceptive respiratory muscles

Question 33

Describe the jobs of the 5 superficial extrinsic muscles of the back

Answer 33

1) Trapezius: elevation, retraction, and depression of shoulders; helps with extension of neck
2) Latissimus dorsi: pushup muscle, pulls downward
3) Levator scapulae: along with trapezius it attaches to the superior angle to to the spine (C2 ish ), allows to shrug shoulders along with trap
4) Rhomboid: ties scapula to midline (when squeezing scapulas together)
5) Serratus posterior superior and inferior mm.: superficial respiratory; proprioceptive in function

Question 34

1) How are the extrinsic back muscles innervated and what do they do?
2) What is the exception?

Answer 34

1) By anterior rami of c-spinal nerves, act on UE (except for trapezius).
2) Trapezius m. innervated by spinal accessory n., CN XI

Question 35

1) What are the muscles of the back proper?
2) What innervates them?
3) What do they do?
4) Where are they?
5) What are their groups?

Answer 35

1) The intrinsic muscles of the back
2) Posterior rami branches of spinal nerves
3) Maintain posture and control ROM of the vertebral column
4) Below investing fascial (“invested” in deep fascia) midline to transverse processes and angle of the ribs
5) Superficial, intermediate, and deep layers

Question 36

How are intrinsic muscles grouped? List them

Answer 36

In relationship to surface: superficial, intermediate, & deep

Question 37

1) Give the brief explanation of what intrinsic muscles are innervated by and what they do
2) What are the enclosed in?

Answer 37

1) Innervated by posterior rami of spinal n.; control posture and movement of the spine
2) In deep fascia (thoracolumbar fascia)

Question 38

1) What is a part of the intrinsic superficial layer?
2) What are its actions?

Answer 38

1) Splenius group
2)
-Unilateral actions: lateral flexion (and rotation)
-Bilateral actions: extend head and neck

Question 39

1) What is a part of the intrinsic intermediate layer?
2) What are its actions?
3) How are they grouped?
4) Where are they?

Answer 39

1) Erector spinae muscles (sacrospinalis)
2) Chief extensors of the spine; some are bilateral
3) Divides into 3 muscle columns
4) Occupy “groove” between spinous process and angles of the ribs

Question 40

1) What is a part of the intrinsic deep layer of muscles?
2) Where do they originate?
3) Where are they?

Answer 40

1) Transversospinales muscle group
2) Originate from transverse processes of vertebrae and pass to spinous processes of more superior
3) Occupy the “gutter” between spinous process and the transverse processes

Question 41

1) Where are the suboccipital region and suboccipital triangle?
2) What is it made of?

Answer 41

1) Deep to trapezius and semispinalis capitis mm.
2) 4 small muscles

Question 42

1) What kinds of muscles form suboccipital region?
2) What are they?

Answer 42

1) Mainly postural muscles, act on head (capitis)
2) Rectus capitis posterior major and minor; obliquus capitis superior and inferior

Question 43

1) What are the 4 muscles of the suboccipital triangle innervated by?
2) What is unique about this area?

Answer 43

1) Posterior ramus of C1; suboccipital nerve
2) No skin sensory component on posterior neck or scalp

Question 44

What do the muscles of the suboccipital triangle do?

Answer 44

1) Bilaterally: extend head on vertebra C1
2) Involved with rotation of head between vertebrae C1 on C2

Question 45

What is the clinical correlation of the greater and lesser occipital nerves?

Answer 45

-Can cause occipital neuralgia, which is defined as chronic headaches by the occipital nerves
-Sometimes a nerve block is placed in the greater occipital nerve at the back of the neck

Question 46

1) What space is spinal anesthesia placed for surgical procedures?
2) What space are CSF samples collected from? What are they also called, and where on the spine do they go?
3) What space is epidural anesthesia placed?

Answer 46

1) Spinal anesthesia: subarachnoid space
2) Subarachnoid space; aka lumbar taps. Done on lumbar cistern below L1-2 where spinal cord ends.
3) Epidural space

Question 47

What is the pathway of epidurals and LPs (lumbar punctures)?

Answer 47

1) Skin
2) Spinous ligament
3) Ligamentum flavum
4) Epidural space: epidurals stop here
5) Dura-arachnoid meninges
6) Subarachnoid space: lumbar punctures stop here

Question 48

What does CN1 innervate?

Answer 48

Doesn’t really innervate the skin, most innervates the muscles of occipital triangle

Question 49

Describe the origins and courses of the greater and lesser occipital nerves

Answer 49

1) Greater occipital nerve: comes from the dorsal rami of C2, goes up the back of head, emerges inferior to obliquus capitis inferior and ascending to posterior scalp
2) Lesser occipital: come from anterior rami of C2-3, goes directly to skin