The Back Flashcards
Verterbral discs provide..
Whole coloumn provides..
Stability
Felxability
The Back can be described as a yacht mast and rigg: Explain basic back anatomy with this
A (jointed) mast (vertebral column)
Spars (Ribs and transverse processes)
Rigging / Stays (muscles & ligaments)
Hull (pelvis) - stable base
Describe the curvature of the spine for each region (cervical, thoracic, lumbar and sacral/coccygeal)
Cervical curve: infront
Thoracic: Behind
Lumbar: infront
sacral/coccygeal: behind
How does the spine chaange curverature during growth and development
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
Examples of abnormal spine curves with brief description
- 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. - Kyphosis
- happens alot in the eldery, their muscle defination becomes quite inbalanced, osteoporosis and artiritis also dont help
- common in thoracic region - 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.
Why are Cervical. thoracic and lumbar located where they are in the body (cross section)
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
Origins and Insertions of DEEP back muscles
Multifidus
Iliocostalis
Longissimus
Spinalis
Multifidus
o= Transverse process
i= Spinous process of vertebrae above
Iliocostalis
o= Illium (pelvic girdle)
i= Lower 6 ribs
Longissimus
o= Spinous processses of sacral and lumbar vertebrae
i= Transverse processes of thoracic vertebrae and ribs
Spinalis
o= Spinous process of lower vertebrae
i=Spinous process of upper vertebrae
Basic structure of typical vertebra
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
Linkages: Intervertebral disc: Anulus fibrosis and Nucleus Pulposus description
type of bone and key features
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
Draw the nucleus Pulposus and verterbral bodies
Sandwhich
verterbral body
nucleus Pulposus
verterbral body
Why are you taller in the morning than afternoon
Also why do you have more back pain/cant lift as heacy when older
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
What happens when there is an area of distortion in Nucleus pulposus
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
What are the ligaments of the spine and label on diagram
1 - Anterior longitudinal ligament
2 - Posterior longitudinal ligament
- Ligamentum flavum
- Interspinous ligament
- Supraspinous ligament
What is the overall structure called of hyaline cartiliage+N+A+hyaline cartiliage
Intervertable symphysis
SUPERFICIAL Muscles ( Extrinistic) of the back and where are they
Latissimus dorsi
Trapezius
Rhomboids major and minor Levator scapulae
Why does intervertablral disc herniation occur
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.
INTERMEDIATE (Extrinsitic) Muscles of the back and where are they
Serratus posterior superior
Serratus posterior inferior
- attach to the ribs and the superior lifts the ribs up (inhalation), inferior pulls the ribs down (exhalation)
DEEP muscles (Intrinsitic) of the back
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)
Pattern as you go down spine
as you go down vertebral column you are sacraficing flex and movement for STABILITY
Neural Supply:
Spinal nerves have 3 parts..
anterior rami -> brachial plexus and upper limb
Post rami - nerve supply of back
Rami communicates - IV disc
Neural supply to Intrinsic back muscles
Posterior Rami
Neural supply to
Intervertebral disc
Mainly rami commincates
(Ligaments and outer 1/3 only)
Types of nerves in spine
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
Why does back pain take so long to accumuluate
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
Why does back pain so hard to localise
Fibres that go through rami commi also supply the vertrebral disc then come to the sympathetic chain which can run up or down the vertbral coloumn. So spinal nerves can get nerve supply also from IV disc above and below it so can get confusing when trying to localise the pain
