Back Flashcards
How many vertebrae are there?
Give break down
33 vertebrae
7 cervical
12 thoracic
5 lumbar
5 sacral
3 coccygeal
In between which vertebrae does significat motion occur?
The 25 superior vertebrae
What does the sacrum form from?
5 sacral vertebrae that fuse in adults
The 4 coccygeal vertebrae fuse at what age and what do they form?
Form the coccyx
Approximately 30 years of age
What is the trend in size of vertebra?
Gradually become larger upto sacrum and then become smaller towards the apex of the coccyx
Why do vertebrae change size?
Increased amount of body weight.
How is weight transfered from vertebral column to pelvic girdle?
Sacrum transfers weight to pelvic girdle via the sacro - iliac joints
Why is the Vertebral column flexible?
It consists of many small vertebrae
What separates vertebrae
IV (intervertebral) disks
What facilitates movement in cervical, thoracic and lumbar vertebrae
Articulation at facet joints
What is the function of the IV discs?
Cushion vertebrae and absorb shocks
What are the 2 components of the IV discs
Nucleus pulposus
Anulus fibrosus
What are the typical land marks of a vertebrae?
Vertebral body
Vertebral arch
7 processes
What is the purpose of the vertebral body?
To give strength to the column and support body weight
What are pedicles?
Short cylindrical processes that project posteriorly from vertebral body to meet laminae
What is vertebral canal aka?
Spinal canal
What does the vertebral canal contain?
Spinal cord
Roots of spinal nerves
Meninges
Fat and vessels
What are the 7 processes of a vertebrae?
1 spinous process
2 transverse processes
4 articular processes ( 2 superior and 2 inferior)
What are the characteristics of the C3 - C6 cervical vertebrae?
- Smallest and lightest vertebrae
- Spinous processes are short and bifid
- Transverse processes contain foramina - vertebral arteries pass through to brain
What are the characteristics of the C7 vertebra?
- longest spinous process (not bifid)
- 1st vertebra that can be palpated
What are the characteristics of the C1 vertebra?
Atlas
- Has no body and formed of 2 lateral masses
- facets articulate with occipital condyles (atlanto-occipital joint)
- joint allows flexion, extension and lateral moment (no rotation)
What are the characteristics of the C2 vertebra?
Axis
- forms joint with atlas (atlanto-axial joint)
- joint allows rotation
- Has upright dens (odontoid processes) that act as pivot
Thoracic Vertebrae
- 12
- Larger than cervical vertebrae
- have 2 costal demi facets (articulating surfaces with head of ribs)
- ## long spinous processes that hook sharply downwards
Lumbar Vertebrae
- 5 (L1-L5)
- Have short, hatchet shaped spinous processes
- most sturdy of all vertebrae
What are the specialities of the thoracic vertebrae?
- Articulate with ribs
- High degree of rotation permitted here
- Limited flexion and extension due to spinous processes
- Spinous processes can be palpated
What is the sacrum formed by?
Fusion of 5 vertebrae
What does the sacrum form posteriorly?
Posterior wall of the pelvic cavity
What is the Coccyx formed from?
Fusion of 4 tiny, irregular shaped vertebrae
What is the name for the holes in the sacrum?
Anterior sacral foramina
What is vertebral body osteoporosis?
A common metabolic bone disease that reduces quality of bones
Caused by a net demineralisation of bones - disruption of calcium deposition and resorption
What are the most affected areas of osteoporosis?
Neck of femur
Body of vertebrae
Metacarpals
Radius
Bones become weakened and can fracture
What are the 3 stages of osteoporosis?
Early - verticak striations (lines) in bodies
Moderate - Radiolucency (less white, more transparent)
Later - Thoractic kyphosis (excessive curvature of spine) - due to collapsed vertebral bodies
What is laminectomy?
The surgical extension of spinous process and vertebral laminae/pedicles
What is laminectomy used for?
Gaining access to the vertebral canal and spinal cord
OR
To receive pressure on spinal cord caused by tumour, herniated disc or bone hypertrophy
Disc account for what percentage of the length of the vertebral column?
25%
What is the anterior longitudinal ligament?
What does it cover/connect?
Strong fibrous band
Covers and connects anterolateral aspects of the vertebral bodies and IV discs
What does the anterior longitudinal ligament prevent and limit?
Prevents hyperextension of vertebral column
Only ligament which limits extention
Posterior longitudinal ligament
- Narrow and weak band
- Runs within vertebral canal along posterior aspect of the vertebral bodies
- Weakly resists hyperextension and helps prevent posterior herniation of the IV disc
What movemnent can the cerviacl spine undergo?
- Rotation
- Flexion / extension
- Side flexion
What movement can the thoracic spine undergo?
*Rotation
What movement can the lumbar spine undergo?
- Flexion / extension
- Lateral flexion
How many curvatures are there in an adult’s spine?
4
The cervical and lumbar curvatures are?
Lordoses
Concave from posterior view
Secondary curvatures
The thoracic and sacral curvatures are?
kyphoses
Concave from anterior view
Primary curvatures
What is the Herniation of nucleus pulposus (IV discs)
- Protrustion of nucleus pulposus into anulus fibrosis
- Casues frequent back pain
- Often happens posterolaterally where anulus fibrosis is thinnest - no support anteriorly or posteriorly by longitudinal ligaments
What do the extrinsic muscles of the back do?
Move the upper limbs and ribs
What do the Intrinsic muscles of the back do?
Move the vertebral column and head
Maintain postire
Where are the erector spinae muscles found?
Either side of the vertebral column
What 3 columns are the intrinsic back muscles divided into?
- Lateral - Iliocostalis
- Intermediate - Longissimus
- Medial - Spinalis
(each of these 3 are further split into lumborum, thoracic and cervicis)
Spinal cord
- It begins as a continuation of the medulla oblongata
- 45cm in legnth
- Extends to L1/L2 (shorter than vertebral column)
What is the collection of the spinal nerves caled?
Cauda equina
What is the name of place were spinal cord ends?
Conus Medularis
How is the spinal cord of a fetal/new born different?
- Different growth of vertebral column and spinal cord during fetal development
- Spinal cord terminates at L3 in a new-born
What is the spinal meninges made up of?
*Spinal dura mater
*Spinal arachnoid mater
*Spinal pia mater
What is the function of the spinal meninges?
They surround and
support the spinal cord and
contain the CSF (cerebrospinal fluid)
What is the dura matter?
The outermost covering
membrane of the spinal cord
What is the spinal arachnoid matter?
A delicate structure that encloses
the CSF filled subarachnoid space
Its separated from pia mater by subarachnoid space (containing CSF)
What is the spinal pia matter and what are its characteristics?
The innermost covering membrane of the spinal cord
*Thin and transparent
*Continues as the filum terminale
*Suspended in the dural sac by the filum terminale and denticulate ligaments
What is a lumbar spinal puncture used for?
Withdrawal of CSF from the lumbar cistern (subarachnoid) - used as important diagnostic tool
What can alter the cells of the CSF (cerebrospinal fluid)?
Meningitis and diseases of the central nerous system
