Curso de Medicina

TraumANATOMIA:

trauma

RAQUIMEDULAR

2014

Leão HZ (Professor de Morfologia – ULBRA)

Juan Zambon(Acadêmico de Medicina – ULBRA)

Patrícia Comberlato(Acadêmica de Odontologia – PUCRS)

Quino

DOIS MINUTOS

Aspectos anatômicos da coluna

vertebral e medula espinal

• The bony spinal column encases and

protects the spinal cord. The spinal cord is

40–45 cm in length,cylindrical in shape,

starts at the base of the brain, exiting

through the foramen magnum, and

terminates in the conus medullaris at

roughly L1–L2, although this can range

from T12 to L3.

Legome, 2011

Aspectos anatômicos da coluna

vertebral e medula espinal

• The cauda equina emanate from the cona

medullaris.

• The spinal cord is divided into neurological

units, labeled after vertebral levels, i.e., C1,

C2, etc. However, within the spinal cord, a

C8 neurological level exists. This is not true

of the bony spine.

Legome, 2011

Aspectos anatômicos da coluna

vertebral e medula espinal

• The spinal cord gives off 31 spinal nerves,

(8 cervical, 12 thoracic, 5 lumbar, 5 sacral,

1 coccygeal).

• Spinal nerves consist of anterior (ventral)

and posterior (dorsal) nerves, containing

efferent and afferent axons, respectively.

These nerves exit the spinal column through

bony foramina.

Legome, 2011

Aspectos anatômicos da coluna

vertebral e medula espinal

• From C1 to C7, the nerve roots exit the

spinal column above the corresponding

vertebra. At theC7 vertebra, C8 roots exit

below the vertebra.

• All roots caudal to C7 exit inferior to the

vertebra.

Legome, 2011

Aspectos anatômicos da coluna

vertebral e medula espinal

• Fusiform enlargements of the spinal cord

exist in the cervical as well as the lower

thoracic/upper lumbar regions. The

enlargements give rise to the brachial and

lumbo-sacral plexuses that innervate the

arms and legs respectively. The amount of

space not occupied by the cord is reduced at

these levels. Consequently, the cord is more

easily compressed in these locations.Legome, 2011

Aspectos anatômicos da coluna

vertebral e medula espinal

• The most commonly injured spinal cord

level is C5, whereas the thoracolumbar

junction (T12–L1) is the most frequent

lumbar level.

• Transection of the cord above C5 causes

tetraplegia. Respiratory failure may occur if

the transection is superior to C4.

Legome, 2011

Aspectos anatômicos da coluna

vertebral e medula espinal

• Mirroring the brain, the cord is covered by

three meningeal layers, the pia, arachnoid,

and dura maters.

Legome, 2011

Sistema vascular

• Vascular supply of the spinal cord is

divided into anterior and posterior vessels.

--- Arterial

• Both the anterior and posterior circulation

systems of the cord receive contributions

from the radicular and medullary arteries

Legome, 2011

Sistema vascular

--- Arterial

1. Anterior arterial vessel: The anterior spinal

artery (from the union of the vertebral

arteries), runs the entire length of the cord

in the midline, supplies the anterior

circumferential two thirds of cord and the

central gray matter.

Legome, 2011

Sistema vascular

--- Arterial

2. Posterior arterial vessels supply the

remaining third circumferential of posterior

cord. The anastomotic flow between the

anterior and posterior arterial systems is

poor. Both arterial systems contribute to a

net-like arterial plexus surrounding the

thoracic, distal cervical, and proximal

lumbar cord.

Legome, 2011

Sistema vascular

--- Arterial

While redundancy in the arterial supply of

this area exists, this area is felt to be at

greater risk of ischemia than the very upper

and lower ends of the cord during episodes

of hypotension.

Legome, 2011

Pós e

Pré-atlântica

Legome, 2011

Sistema vascular

--- Venous

• The venous system of the cord follows the

arterial system, draining into the internal

and external venous plexuses.

• The internal venous plexus passes

superiorly and communicates with the dural

sinuses and vertebral veins in the skull.

• The external venous plexus lies on the

external surface of the vertebrae.

Legome, 2011

Legome,

2011

Medula espinal

• The cord itself is made up of gray and white

matter. White matter concentration is greatest

in the cervical spinal segments (as a

consequence of the large density of axonal

fibers).

• The butterfly-shaped gray matter sits

centrally and contains the nerve cell bodies

and their processes, whereas the white matter

is a collection of the myelinated ascending

and descending axonal fibers known as tracts.

Legome, 2011

Magnetic resonance

imaging provides the

best visualization of

the soft tissues,

spinal cord,

and spinous

ligaments

Legome, 2011

At this time, MRI cannot predict neurological status at 6

weeks in cases of cord hemorrhage, edema, and contusion.

If a patient is very unstable, check a cross-table lateral

cervical spine X-ray. It will provide basic information about

the cervical spine.

None of these

diagnostic studies

are therapeutic

Legome, 2011

Medula espinal

• Multiple tracts exist.

• Important spinal cord tracts are the posterior

columns (medial and lateral), spinothalamic

tract, and corticospinal tract. The tracts are

named for their origins (i.e., corticospinal

tract starts in the cortex, travels to the spine)

Legome, 2011

Legome, 2011

Legome, 2011

Spinal cord injury terminology

• Tetraplegia (formerly known as

quadriplegia) is injury to the spinal cord in

the cervical region with associated loss of

muscle strength in all four extremities.

• It can be complete – lacking sensory and

motor, or incomplete – having one or both

of these neurologic functions partially or

completely intact.

Legome, 2011

Spinal cord injury terminology

• Paraplegia is injury to the spinal cord in the

thoracic, lumbar, or sacral regions,

including the cauda equina and conus

medullaris, sparing the upper extremities.

Legome, 2011

Pathology of spinal cord injury

• Spinal cord injury can be sustained through

multiple mechanisms.

The spinal cord suffers two distinct

injuries:

• the initial or primary injury and

• a later secondary insult.

Legome, 2011

Pathology of spinal cord injury

The following list details the common

mechanisms (primary injuries) leading to

tissue damage:

• 1. Destruction from direct trauma.

• 2. Compression by bone fragments,

hematoma, or disk material.

• 3. Ischemia from damage or impingement

on the spinal arteries.

Spinal cord edema could ensue secondary to any

of the above.Legome, 2011

Pathology of spinal cord injury

The phenomenon of the secondary insult is

still not entirely clear, but the various

pathways are better understood now.

Currently, secondary injury is believed to

be a highly complex combination of

• cord hypoxia,

• calcium efflux,

• cell apoptosis,

• free radicals,

• and generalized inflammation.Legome, 2011

T2-weighted magnetic

resonance imaging

(MRI) image of C4–C5

complete cord

transection. C3–C5

subluxation with

anterolisthesis of

C4 and C5 and

concurrent

retrolisthesis of C5 on

C6. An epidural

hematoma is visible,

along with prevertebral

and posterior

paraspinous soft tissue

hematoma/edema.

Obrigado por participarem