The Back

Question 1

Verterbral discs provide..

Whole coloumn provides..

Answer 1

Stability

Felxability

Question 2

The Back can be described as a yacht mast and rigg: Explain basic back anatomy with this

Answer 2

A (jointed) mast (vertebral column)

Spars (Ribs and transverse processes)

Rigging / Stays (muscles & ligaments)

Hull (pelvis) - stable base

Question 3

Describe the curvature of the spine for each region (cervical, thoracic, lumbar and sacral/coccygeal)

Answer 3

Cervical curve: infront
Thoracic: Behind

Lumbar: infront
sacral/coccygeal: behind

Question 4

How does the spine chaange curverature during growth and development

Answer 4

At birth there is greater curve of the T and as u get to 5months there is more tummy time etc, so the T becomes less curved with the S becoming slightly more curved. This continues till 8 years where the L becomes significantly more curved to acc the COG. At 10 years, there is 2 degree curve at C and L, 1 degree curve at T and S

Question 5

Examples of abnormal spine curves with brief description

Answer 5

1. Scoliosis
   - lateral deviation
   - everyone has a natural scoliosis as tend to have a dominant side so the muscles tend to be heavier and stronger which tends to push our spines over a bit, ususally mild and doesnt impact day to day life.
2. Kyphosis
   - happens alot in the eldery, their muscle defination becomes quite inbalanced, osteoporosis and artiritis also dont help
   - common in thoracic region
3. Lordosis
   - Sometimes kids have this before abdominal muscles have developed
   - Pregnancy is a common cause of this, putting Thoracic region back to acc the weight and thus more curve in L region.

Question 6

Why are Cervical. thoracic and lumbar located where they are in the body (cross section)

Answer 6

Cervical - located 1/3 back from posterior in order to help acc esphagus larynx etc and to support the head

Thoracic: Acc organs and be able to chnage volume of thoraci cage and so sits further back about 1/4 from posterior

Lumbar sits 1/2 posterior. Closer to the centre as weighr bearing and lots of mass on verterbrae, close to COG

Question 7

What are the components of the spine

Answer 7

• joints
  -ligaments
• muscles
• nerve supply

Spine has a protective and supportive role

Lecture slide

Question 8

Basic structure of typical vertebra

Answer 8

1 - vertebral body
2 – vertebral arch
3 & 4 – superior (and inferior) articular
processes
5 & 6 – transverse processes
7 – spinous process
8 & 9 – pedicles
10 & 11 – laminae

Question 9

Linkages: Intervertebral disc: Anulus fibrosis and Nucleus Pulposus description

type of bone and key features

Answer 9

Very tough joint
Syndesmosis (fibrocartiligious) allowing small amounts of movement

N and A

N:
Nucleus Pulposus
- glycoproteins
Proteoglycans
Hyaluronic acid
(All very hydrating)

• Located in the centre of intervertbral disc by annulus fibrosis
• When load is applied the hydrated centre can only be compressed so much before too much hydrostatic pressure develops and u cant compress it anymore
• Acts as a deformed pivtal point as two points of contact with (one each for vertrbeal vodies) allowing the plates to chnage direction

A
Annulus fibrosis:
- fibrous rings
- layers of collagen
- Orthogonal (collagen changes direction in each ring so some rings will always be in tension
- Fibres can be up to 90 degrees out of phase
- Oritentaion changes with different regions of the coloumn
ie lumbar region has quite horizontal rings to limit rotation

Question 10

Draw the nucleus Pulposus and verterbral bodies

Answer 10

Sandwhich

verterbral body
nucleus Pulposus
verterbral body

Question 11

Why are you taller in the morning than afternoon

Also why do you have more back pain/cant lift as heacy when older

Answer 11

2cm taller in morning as some of the water inside the nucleus pulposus is squeezed out during the day (lose 1mm per interverbral disc - have 23 of them)

Rehydrated when not loaded but glycoproteins and proteoglycans cross link when get older and not as hydrophilic

Question 12

What happens when there is an area of distortion in Nucleus pulposus

Answer 12

Creates an a compressed area of spinal nerve by brinign the N too close to the spinal nerve and leading to connection to the superior articualr process

Question 13

What are the ligaments of the spine and label on diagram

Answer 13

1 - Anterior longitudinal ligament

2 - Posterior longitudinal ligament

3. Ligamentum flavum
4. Interspinous ligament
5. Supraspinous ligament

Question 14

What is the overall structure called of hyaline cartiliage+N+A+hyaline cartiliage

Answer 14

Intervertable symphysis

Question 15

SUPERFICIAL Muscles ( Extrinistic) of the back and where are they

Answer 15

Latissimus dorsi
Trapezius
Rhomboids major and minor Levator scapulae

Question 16

Why does intervertablral disc herniation occur

Answer 16

Slipped disc
-no way you could actually slip an intervertebral disc, the Annulus fobrosis goes through and blends with fibres of the bone. So the attachment is really strong , no way an entire disc will slip out between the intervertbreal bodies

Can ger herniation of the Nucleus (severe back pain)

Most back pain is caused by hyperflexing your spine under lots of load. Normally when you put load on to intervertebral bodies nucleus
pulposis is very well situated to resist the compressive force which is trying to push nucleus pulposus into the vertebral body below.
however, if you change the angle increase the load by trying to pick something up
There is a net force on nucleus pulposus pushing it posteriorly overtime this can weaken annulus fibrosis and it can cause nucleus pulposus to start to herniate posteriorly

anterior longitudinal lig. helps brace the front but posterior longitudinal lig doesnt really go as wide as the anterior does which creates two weak points, one on each side.

Question 17

INTERMEDIATE (Extrinsitic) Muscles of the back and where are they

Answer 17

Serratus posterior superior
Serratus posterior inferior

• attach to the ribs and the superior lifts the ribs up (inhalation), inferior pulls the ribs down (exhalation)

Question 18

DEEP muscles (Intrinsitic) of the back

Answer 18

lliocostalis
Longissimus
Spinalis
Multifidus

these muscles are so long that are divided up into regions
- capitis (head)
-Cervicis (neck)
-Thoracis (thorax)
-Lumborum (associated with lumbar) (area we mostly get back pain)

Question 19

Pattern as you go down spine

Answer 19

as you go down vertebral column you are sacraficing flex and movement for STABILITY

Question 20

Neural Supply:
Spinal nerves have 3 parts..

Answer 20

anterior rami -> brachial plexus and upper limb

Post rami - nerve supply of back

Rami communicates - IV disc

Question 21

Neural supply to Intrinsic back muscles

Answer 21

Posterior Rami

Question 22

Neural supply to
Intervertebral disc

Answer 22

Mainly rami commincates
(Ligaments and outer 1/3 only)

Question 23

Types of nerves in spine

Answer 23

Segmental Spinal nerves
- Meningeal branches of the spinal nerve (Sinuvertebral nerve)
- Sinuvertebral nerve supplies to meninges, joints, periostenum, IV disc

Non- segmental
- Sympathetic chain from the rami communicans of spinal nerves

Question 24

Why does back pain take so long to accumuluate

Answer 24

nerves don’t penetrate
any further than annulus fibrosis so herinated disc has to herniate quite a bit before it actually starts to stimulate nerve supply and cause pain this is why bakc pain is regostered long affter damage