Unit 6 The spine Flashcards
What is the vertebral column?
A series of 33 bones called vertebrae linked by intervertebral disks
What are the four main functions of the vertebral column?
Protection of the spinal cord
Support by carrying the weight above the pelvis
Axis - is the central axis of the body
Movement - posture, movement and flexibility.
What are the five different sections to the vertebral column and how many vertebrae are in each section?
Cervical - 7
Thoracic - 12
Lumbar -5
Sacrum -5 fused
Coccyx - 4 fused
What is the vertebral body?
The anterior section of a vertebrae.
Weight bearing component
Body get larger more inferiorly in order to support more weight.
What are intervertebral disks?
Found between vertebrae.
Hyaline cartilage lines the superior and inferior surfaces of vertebrae.
A fibrocartilaginous disc fills the space
What is the vertebral arch?
Forms the lateral and posterior aspect of the vertebrae from lamina posterior.
Where is the spinal cord found?
Within the vertebral canal which is the alignment of the vertebral foramen from each vertebrae.
What features are common in all vertebral arches?
Spinous processes
Transverse process
Pedicle
Lamina
Articular processes
What are some unique features of a cervical vertebrae?
Bifid (bifurcating)spinous processes except in C1 (no sp) and C7 where the processes is long
Transverse foramina acts as opening for the vertebral arteries to travel to the brain
Triangular vertebral foramen
What vertebrae allows for movement of the head?
C1 atlas
C2 - axis
What are some features unique to the thoracic vertebrae?
Has superior and inferior demi facets for rib articulation.
Transverse process has a costal processes for the rib of the same number.
Circular vertebral foramen.
What are some features unique to the lumbar vertebrae?
Very large and kidney shaped vertebral bodies.
Triangular shaped vertebral formane
Short spinous processes
Shape allows needle access to the spinal cord.
What are some features of the sacrum?
Five fused vertebrae
Inverted triangle with an inferior apex
Lateral walls are part of the sacroiliac joint
What are some features of the coccyx?
Has no vertebral arches so no vertebral canal
What is lumbarisation?
Separation of S1 from the sacrum.
A congenital abnormality
What is sacralisation?
Fusion of L5 to the sacrum.
A congenital abnormality
What are congenital abnormalities?
Present at birth or of prenatal origin.
What joints connect the vertebrae together?
Superior and inferior articular facets.
Indirectly by the intervertebral discs.
What ligaments strengthen the vertebral bodies?
What is their function?
The anterior and posterior longitudinal ligaments.
Run the full length of column
Anterior is thick and prevents hyperextension.
Posterior is weaker and prevents hyperflexion.
Support the vertebral bodies.
What ligaments support the vertebrae joining at articular surfaces?
Ligamentum flavum - between lamina
Interspinous and suraspinous - attack two spinous proceses, supra attaches tips, inter is between the main length
intertransverse ligaments - between transverse processes.
What are the brain ventricles?
Four hollow fluid filled cavitys, containg CSF found in the centre of the brain.
The lateral ventricles
The third ventricle
The fourth ventricle
What is the choroid plexus?
Specialised tissue found in the brain ventricles.
Produces CSF.
What is the function of the CSF?
Made in the ventricles, fills the subarachnoid space.
Cushions the brain, supporting its weight to protect from mechanical damage.
Provides nurtitional and immune support to the brain.
What is the journey of the CSF?
Lateral ventricles
Anterioly and inferiorly towards the midline down the interventricular foramanen
Third ventricle
Posteriorly and inferiorly through the cerebral acqueduct to the fourth ventricle.
Inferiorly for the spinal cord subarachnoid space via the foramen of magendie.
OR laterally into the subarachnoid space of the brain via foramen of lushka.
Describe the location of the third and fourth ventricle
Third is located between the left and right thalamus
Fourth is anterior to the cerebellum and posterior to the midbrain.
What are the three different meningi layers?
The dura mater
The arachnoid mater
The pia mater
Give an overview of the dura mater.
Thickest and toughest of the menigeal layers
Located directly beneath the skull.
Has infoldings called dural reflections.
What are dural reflections?
Foldings of the dura mater down into the brain
Includes the falx cerebri - between the left and right cerebral cortex
………
What are dural venous sinuses?
Found between the endosteal and meningeal layers of the dura matter, these are small cavities. They drain the venous blood of the brain
For example the superior sagittal sinus found along the falx cerebri.
Give an overview of the arachnoid matter.
Above subarachnoid space, pressure in this space holds the arachnoid mater tight against the dura mater.
Has trabeculae fibres that extend through the subarachnoid space to the pia mater.
Give an overview of the pia mater.
The innermost of the meningeal layers
Covers surface of the brain.
Contains blood vessels that are filtered through the blood brain barrier to supply the brain.
What is the blood supply of the menigeal layers?
The middle meningeal artery, is between the dura mater and the inner aspect of the skull.
Originates from maxillary artery that enters the skull through the small cranium spinosum in the middle cranium fossa.
What layers of the spinal meniges can sometimes appear as one layer?
The dura mater and the arachnoid mater, the CSF in the subarachnoid space pushes and puts pressure on the arachnoid matter forcing it outwards towards the dura mater.
What are denticulate ligaments?
Lateral extension bilaterally from the pia mater to attach the the upper meningeal layers (arachnoid and dura).
Help anchor the spinal cord in space within the vertebral canal
What is the epidural space?
Is superficial to the dura mater but deep to the vertebrae.
The site of epidural injection during childbirth, allows the anesthesia to spread around spinal nerves in the proximity.
What are the different elements protecting the CNS?
The bones (cranium and vertebrae)
Meningeal layers
CSF
Where does the spinal cord end?
Where does the dural sac end?
Why is this important clinically?
The spinal cord ends at L1/L2
The dural sac ends at roughly S2.
A needle or lumbar puncture can happen between these vertebral levels in order to sample CSF without the risk of damaging the brain or the spinal cord.
May also be called a spinal tap, often between L3 and L4.
What is the cauda equina?
Continuation of spinal nerve roots through the vertebrae in the lumbar and sacral regions after the spinal cord has ended.
How are spinal nerves numbered?
Cervical regions - nerves are numbered by the vertebrae inferior to it, note the nerves above T1 is called C8
All other regions - named after the Vertebrae above it
How can you identify the posterior region in the sacrum?
Has fusions of the spinous processes remaining.
What cervical vertebrae do not follow the general pattern?
C1 - atlas
C2 - axis
C7 - vertebrae prominens
What are the features of the atlas C1?
No vertebral body, instead it has an anterior arch
Two superior facets for articulation with the occipital condyles
Short non-bifid spinous process
What are the features of the axis C2?
Lacks a vertebral body instead has a dens or odontoid process on its superior surface.
What is the ondontoid process?
A projection from the second cervical vertebrae on which the 1st cervical vertebrae can pivot horizontally.
The odontoid process sits within the anterior vertebral arch.
Called the atlanto-axial joint.
What are the features of the vertebra prominens?
C7 has a long prominent, non-bifid spinous process
Easily palpable on a flexed neck.
What is the function of the supraspinous ligament?
Connects the tips of the spinous process.
Continuous with the nuchal ligament in the neck which attaches to the external occipital protuberance.
Prevents hyperflexion of the spin
What is the function of the nuchal ligament?
Attaches to the external occipital protuberance.
Located in the posterior neck
Is continous with the supraspinous ligament
prevents the head from lulling forwards when muscular exertion is not applied.
What is the function of the intertransverse ligaments?
Attach the transverse processes of adjacent vertebrae.
Limit lateral flexion of the vertebral column.
What are the two layers of the dura mater in the brain?
The periosteal dura mater
The meningeal dura mater
Where is CSF reabsorbed?
Through arachnoid granulations into dural sinuses
Dural sinuses are venous ciruclation between the periosteal and meningeal layers of the dura mater.
What are the layers of tissue in the skull?
Skin and dense subcutaneous connective tissue
Aponeurosis
Loose connective tissue and pericranium
Bone
Dura mater
Arachnoid mater
Pia mater covering the cerebral hemisphere
Where is the epidural space?
A theoretical space between the dura mater and the periosteum
Layers are often fused tightly together, space only filled due to pathology or anaesthetic.
What are the different sections of the lateral ventricle?
The anterior horn
The body
The posterior or occipital horn
The inferior or temporal horn.
Interventricular foramina.
What is the function of CSF?
Nourishes the brain
Protects the brain from injury
Assists in removing waste from the brain
What are the two distinguishable areas of the spinal cord?
Grey matter - mainly cell bodies in the middle
White matter - mainly axons in the outside.
What visible features distinguish the anterior and the posterior of the spinal cord?
Anterior - ventral median fissure (is bigger)
Posterior - dorsal median sulcus
What is the dorsal column?
A bilateral structure found just lateral to the dorsal median sulcus contains the gracile and the cuneate.
Confers fine touch and porciperception to the brain.
What is the central canal of the spinal cord?
Found centrally within the grey matter.
Contains CSF
What is the function of the lateral corticospinal tract?
Supplies motor information to the limbs
What is the function of the ventral corticospinal tract?
Supplies motor information to the axial regions (not limbs)
What is the function of the lateral spinothalamic tract?
Conveys pain and temperature information to the brain
What is the function of the anterior spinothalamic tract?
Carries the sensation of crude touch to the brain
What is the function of lissauers fasicululs?
Carriers crude touch and pressure
What is the function of the anterior white commisser?
Where nerve fibres cross the vertebrae to the contralateral side of the body
Draw a diagram to show the location of the different tracts and the anterior white commisser on the spinal cord.
Note tracts are bilateral - diagram only represents as unilateral
What are the different sections of the lateral ventricles?
What is the function of the central canal?
Space for movement of CSF up and down the spinal column
What is found in the dorsal horn of the spinal cord?
Synpases of sensory neurons
What is found in the ventral horn of the spinal cord?
Cell bodies of motor neurons
What is unique about the cervical spinal cord section?
Is wider in the transverse section than the sagittal section, squashed circle or jelly bean shape.
What is unique about the thoracic spinal cord cross section?
Presence of a lateral horn, contains the cell bodies of sympathetic nerves
Smaller ventral horn, less motor cell bodies, does not innervate the limbs only the trunk so less limbs are needed.
What happens to the ratio of white to grey mater as you move down the spinal cord?
The proportion of white mater decreases
More nerves has left the spinal cord, less axons need transporting in lower sections, hence white mater is less
How can you tell the difference between a lumbar and a sacral spinal cord cross section?
Lumbar is wider
Lumbar has a greater proportion of white rather than grey mater.
Identify the different sections of the spinal cord
- cervical
- thoracic
- lumbar
4.sacral
What is a herniated disk?
When pressure on the intervertebral disk causes the soft, central, gelatinous nucleuspulposus to be pushed out through the outer harder annulus
Can add pressure to local spinal nerves causing pain.
What can cause a herniated disk?
Repeated strain or movement in that area.
Age - lose water content as you get older, less able to support the weight of above vertebrae
Congenital abnormality
Long standing trauma
Stress fractures
What are symptoms of a herniated disk?
Must common in the lumbar or cervical regions
Causes pain in spine
Pain, numbness or tingling in the limbs
Muscle spasms
Worsening when sitting, twisting or bending
If in the cervical region: incontinence, heavy limbs, poor coordinate and balance problems are also common.
How is a herniated disk treated?
Methods to reduce inflammation: hold and cold therapy, corticosteroid injections
Anaglesics to reduce pain.
Rest of strenuous exercise
Stretching and physical therapy
Surgical: Discetemony or laminectomy
From a superior view what is the green section of the vertebrae
Pedicles
(feet on the peddles)
From a superior view what is the purple section of the vertebrae.
The lamina
Froma superior section what is the yellow section of the vertebrae.
Superior articular process
What are the two different types of joints that joint the vertebrae?
The interverterbral disk - cartilagenous joint, symphysis
The superior and inferior articular processes - synovial joint, this joint is called the zygapophysial joint.
What are the different componenets of an intervertebral disk?
The anulus fibrosis - an outer tough fibrous layer in lamellar arrangement, reduces rotation of the intervertebral disk, outer collagen ring surrounding a fibrocartilagenous layer
Nucleus pulpus is the centre - abosrbs the pressure on the disc, is gelatinous in structure.
What is the condus medullaris?
The terminal end of the spinal cord.
What is the cauda equina?
Spinal nerves that arises from the end of the spinal cord
The spinal nerves are bundled together into fasiculations.
What is the filum terminale?
A continuation of the meninges as a strand of fibrous tissue after the spinal cord has ended, eventually fuses with the coccyx.
What are structures A and B in the vertebrae?
The superior and inferior articular processes.
What are the different atypical thoracic vertebrae?
T1 has a full superior facet as rib 1 does not attach to the cervical vertebrae
T10 onwards have full superior facets but no inferior facets, only attach to ribs of their own number
T11 and T12 have no transverse costal processes.
What is the orange ligament?
The anterior longitudinal ligament
What is the purple ligament?
The posterior longitudinal ligament
What is the blue ligament?
The ligamentum flavum
What is the green ligament?
The interspinous ligament
What is the yellow ligament?
The supraspinous ligament
What ligament is this?
The intertransverse ligament
What two ligaments are shown here and what two structures do they connect to?
The nuchal ligament
The supraspinous ligament
The coccyx and the external occipital protuberance
What are the different layers shown in this section?
Spinal cord
Surrounded by the pia mater
Then the subarachnoid space
Then the arachnoid mater
Then the dura mater
The extradural space
What are the different connection point between the ventricles?
what structures leaves the fourth ventricle?
