the spine & spinal cord
TRANSCRIPT
Recognise and name the following parts of a typical vertebra in osteological specimens or in suitable imaging: body, pedicle, lamina, transverse process, spinous process, articular surfaces
Recognise the distinctive features of cervical, thoracic and lumbar vertebrae Explain the roles of intervertebral discs, ligaments and muscles in load
bearing in the vertebral column Describe the relative extents of antero-posterior flexion, lateral flexion and
axial rotation in the major regions of the vertebral column and explain this in terms of skeletal anatomy
Identify the atlas and axis and explain their functions in head movement Identify the main muscle groups involved in head movements Demonstrate on each other the location of C7, T3, T7, L2 and L4 vertebrae State the number of vertebrae in each region of the spine, and how the pairs
of spinal nerves are related to them Explain the arrangement of the meninges around the spinal cord and roots,
and indicate any differences from the cranial meninges Identify two major reasons for carrying out lumbar puncture, and explain the
basis for the puncture site Explain the danger of carrying out lumbar puncture without excluding the
presence of raised intracranial pressure Outline the steps taken to avoid neurological complication in casualties with
a possibility of cervical spine injury Explain in anatomical terms the most common causes of back pain Describe the most common abnormalities of spinal curvature
C1-C7 T1-T12 L1-L5 S1-S5 Coccyx
LANDMARKS
C7 – Prom. Spinous Process
T3- Level with Medial Scapular Spine
T7 – Inferior angle of scapula
L2 – Lowest Rib
L4 – Iliac Crest
Vertebra
Cervical vs Thoracic vs Lumbar
Cervical vertebrae
Smallest
Foramen in each transverse process
What is this?
C1 –Atlas
Forms the joint connecting the skull and spine
Has no body
AXIS (Second cervical vertebra)
(C2) of the spine is named the axis.
It forms the pivot upon which the Atlas- rotates
strong odontoid process which rises perpendicularly from the upper surface of the body.
Thoracic Vertebra
Intermediate in size Increase in size as one
proceeds down the spine They are distinguished by
the presence of facets on the sides of the bodies
Facets on the transverse processes of all, except the eleventh and twelfth,
Lumbar Vertebra
The lumbar vertebrae are the largest segments of the movable part of the vertebral column
Absence of a foramen in the transverse process,
Absence of facets on the sides of the body.
The cervical curve, convex forward, C1/2 – T7
The thoracic curve, is concave
T2 – T12
The lumbar T12 – L4, It is convex anteriorly.
The pelvic curve L4/5 - Coccyx
Intervertebral Disk
Each disc forms a cartilaginous joint to allow slight movement of the vertebrae, and acts as a ligament to hold the vertebrae together.
The annulus fibrosus consists of several layers of fibrocartilage. The strong annular fibers distribute pressure evenly across the disc.
The nucleus pulposus contains loose fibers- like JELLY. The nucleus of the disc acts as a shock absorber, absorbing the impact of the body's daily activities and keeping the two vertebrae separated.
Intervertebral Disk - INJURY
Degenerative Disk Disease: As people age, the nucleus pulposus begins to dehydrate, which limits its
ability to absorb shock. The annulus fibrosus gets weaker with age and begins to tear. While this may not cause pain in some people, in others one or both of these may cause chronic pain.
Disk Herniation: When the annulus fibrosus tears due to an injury or the aging process, the
nucleus pulposus can begin to extrude through the tear.
Leads to Pinched nerve: Radiating pain, numbness, tingling, and diminished strength and/or range of
motion.
Radicular Pain
From Course Guide
Why is backache more common in the lumbar region? The lower spine is subject to increased stresses of weight-bearing.
We tend to abuse our backs, particularly when lifting heavy objects. Extending the spine from the fully flexed position under a heavy load can inflame intervertebral joints or place unequal pressure on the intervertebral disks, leading to local joint pain and referred neurological pain, if there is also pressure on the spinal nerve. Additional attempts to rotate the spine at the same time creates extra stress on the lumbar joints.
Good practice includes holding the load close to the body, and using extension of the knee joints instead of extension of the spine to raise the load.
Flexibility and Mobility
Flexion (forward bending) Extension (backward bending) Side bending (left and right) Rotation (left and right) Combination of above
MUSCLES ASSOCIATED WITH
From Course Guide…
Flexion/extension Lateral flexion Rotation
C1-C7 ++ ++ ++
T1-T6 0 + +
T7-T12 + ++ ++
L1-sacrum ++ + 0
Abnormalities in curvature
The following abnormal curvatures may occur in some people: Kyphosis is an exaggerated posterior curvature in the thoracic
region. This produces the so-called "humpback".
Lordosis is an exaggerated anterior curvature of the lumbar region, "swayback". Temporary lordosis is common among pregnant women.
Scoliosis, lateral curvature, is the most common abnormal curvature, occurring in 0.5% of the population. It is more common among females and may result from unequal growth of the two sides of one or more vertebrae.
Lumbar Puncture
Indications Collect cerebrospinal fluid- in a case of suspected meningitis. (Subarachnoid hemorrhage, hydrocephalus, benign intracranial
hypertension and other diagnoses may be supported or excluded with this test.)
Lumbar punctures may also be done to inject medications into the cerebrospinal fluid or lumbar epidural space.
Risks Damage to the spinal cord or spinal nerve roots resulting in weakness
or loss of sensation, or even paraplegia. The latter is very rare. The procedure is not recommended when epidural infection is present or
suspected, when topical infections or dermatological conditions pose a risk of infection at the puncture site or in patients with severe psychosis or neurosis with back pain.
Elevated or reduced pressure in the brain may also pose risks during lumbar punctures.
Vertebrae & Nerve Roots
C1-C7 = AboveC8 = Above T1T1 – Coccygeal = BelowCervical Cord = 1 above SPThoracic = 2 above SPLumbar = 4 above
Spinal Cord
COVER THIS ELSEWHERE!!!
Grey Matter White Matter Pia Mater Arachnoid Mater (nt
attatched to Dura) Dura Mater DENTICULATE
LIGAMENT
Lesion Through Cord
Motor innervation: Partial lesion- Normally via 2 or more segments
of motor neurones, so may WEAKEN but unlikely to paralyse
Problem is – WHITE MATTER
Factors affecting the severity of a spinal lesion
Loss of neural tissue - obvious Vertical level – Higher up, the greater the
damage Transverse plane – What Diameter has a
lesion
Descending tracts
Ascending tracts
Transverse Plane
Remember
Where is it coming from (Up or Down)Where does it synapseWhere does it cross overHow many Synapses
Lateral corticospinal tract
MOTOR
UP –DOWN
Motor cortex
Internal Capsule
Pyramidal Decussation
Lateral Corticospinal
Synapse in ANTERIOR HORN?
Dorsal columns Touch and Proprioception
Bottom Up
Sensory
Periphery – Dorsal Root Ganglion
Ascending Dorsal Columns
Synapse in Medulla
Decussation in Medulla
Synapse in Thalamus
Projection to Sensory Cortex
Central pathway
[touch & proprioception]
Fasciculus Gracilis (M) Fasciculus Cuneatus (L)
Tirgeminal
CROSS IN MEDULLA
UMN – CONTRALATERAL
LMN - IPSILATERAL
Gracile fasciculus
Cuneate fasciculus
Gracile nucleus
Cuneate nucleus
Medial lemniscus
Medial lemniscus
Spinothalamic tract
Sensory
DOWN –UP
LIMB – DRG –
SYNAPSE IN DORSAL HORN
CROSSES@ or near ENTRY
ASCENDING SPINOTHALAMIC
SYNAPSE in THALAMUS
Project onto Cortex
Central pathway
[pain & temperature]
SLTC
TRIGEMINAL
UMN – Contralateral
LMN - CONTRALATERAL
s
c c
Spinothalamic tract
Spinal lemniscus
SPINAL TRAUMA
NERVE ROOT:Herniated Disk/ SpondylosisCervical & LumbarPainParaesthesiaWeakness & muscle wastingReduced SensationLoss of Reflexes
Upper Cervical Cord Lesion
Is effectively an UMN lesion
Spastic Quadriplegia
Hyperreflexia
Extensor Plantars (upgoing)
Sesnory Loss below lesion
Sensory ataxia (un coordinated)
Lower Cervical Cord Lesion
Is effectively a LMN lesion
Weakness, wasting, fasciculation of muscles in upper limbs
And UMN lesion: in LOWER LIMBS
Spastic Paraparesis
Hyperreflexia & Ext.Plantar
Extensor Plantars (upgoing)
Sesnory Loss below lesion
Sensory ataxia (un coordinated)
Thoracic Cord Lesion
LOWER LIMBS
Spastic paraparesis
Hyperreflexia
Extensor Plantar responses
Incontinence
Sensory loss below lesion
Sensory Ataxia
Lumbar Cord Lesion
Weakness, wasting and fasciculations of muscles
Areflexia of lower limbs
Sensory loss
Ataxia
Brown-Sequard syndrome
FRACTURE Basics
GO look at your lecture - it is goodLearn what is on there…… it’s better than
mineQuick run through
Priority 1 – Save a lifePriority 2 – Save the Spine
Spinal Trauma - Initially
If spinal trauma indicated then….ASSUME IT- until excludedGunshot – Head= dnt immobiliseStab – dnt immobilise
Pre- hospital
ACHIEVE ALIGNMENTConscious – ActiveUnconscious – Passive—but be carefulLong Spinal board
Multiple Injuries
Immobilise the WHOLE spine
PAD and STRAP Head Shoulders Pelvis
In Hospital
Off board – Onto firm trolleyLog rollABC DEFG now more relevantREMEMBER:Spinal immobilisation is a priority in
multiple trauma, spinal clearance is not. TREAT THE TRAUMA, then worry about
the spine
Spinal Clearance
Asymptomatic injury – possible but VERY unlikely to be serious
Can’t clear in the field – normally radiology Clinical clearance: Fully alert and orientated No head injury No drugs or alcohol No neck pain No abnormal neurology No significant other 'distracting' injury (another injury
which may 'distract' the patient from complaining about a possible spinal injury).
Radiology
Lateral: C7-T1 junction
Alignment: Posterior more significant than ant.A translation of > 3.5mm is significant anywhere. Spinal canal diameter- >18mm
Anterior subluxation of one vertebra on another indicates facet dislocation.
Examination of the vertebral bodies and the intervertebral disc space
Compression and burst type injuries Bodies should be regular cuboids similar in size and shape to the vertebrae immediately above and below (not C1/C2).
Compression fractures may present as anterior wedging of the vertebral body or teardrop fractures of the antero-inferior portion of the body (compression in flexion).
AP - spinous processes of C2 to T1.
The open-mouth view should visualise the lateral masses of C1 and the entire odontoid peg.
Additionally
CT scan if requiredSoft Tissue injury – image appropriately? MRI
Unconscious, Intubated Patients
The odontoid view is unreliable in intubated patients.
Clinical examination is impossible in the unconscious patient.
Plain film radiology cannot exclude ligamentous instability.
Watch/MRI/CT/Fluroscopy
Thoracolumbar spine
Indicated if there is pain, bruising, swelling, deformity or abnormal neurology attributable to the thoracic or lumbar spinal regions.
The presence of a fracture anywhere in the spine mandates full spinal imaging.
Unconscious patients who cannot be assessed clinically also require radiological clearance of the whole spine.
To Download This Lecture Please Visit Our Website
union.ic.ac.uk/medic/muslim