ANATOMY OF ANATOMY OF SPINESPINE

OUTLINEOUTLINE

Conceptual overview Regional anatomy Surface anatomy Radiological anatomy

Conceptual Conceptual overviewoverview

Functions

Support

Movement <additive>

Protection of central & peri nervous

systems

flexion

extension

lateral flexion

rotation, and

circumduction

curvescurves

Sec curvature bring the center

of gravity to a vertical line,

which allows the body’s weight

to be balanced on the vertebral

column in a way that expends

the least amount of muscular

energy to maintain an

upright bipedal stance.

Conceptual Conceptual overviewoverview

Component parts

Bones

Muscles –Extrinsic- sup,inter; Intrinsic-

deep

Vertebral canal

Spinal nerves

Dermatomes and myotomes

Conceptual Conceptual overviewoverview

Key features

Long vertebral column, short spinal

cord

Intervertebral foramina and spinal

nerves

Innervation of back

Regional Regional

anatomyanatomy

Intervertebral DiscsIntervertebral Discs

LigamentsLigaments

Supraspinous This runs between the tips of adjacent spines.

Interspinous : This connects adjacent spines.

Intertransverse: These run between adjacent transverse processes.

Ligamentum flavum : This connects the laminae of adjacent vertebrae.

cervical region= supraspinous and interspinous ligaments greatly

thickened to form the strong ligamentum nuchae.

LigamentsLigaments

Dislocations and fractures of the vertebral column. A. Unilateral dislocation of the fifth or the sixth cervical vertebra. Note the forward displacement of the inferior articular process over the superior

articular process of the vertebra below. B. Bilateral dislocation of the fifth or the sixth cervical vertebra. Note that 50% of the vertebral body width has moved forward on

the vertebra below. C. Flexion compression–type fracture of the vertebral body in the lumbar

region. D. Jefferson's-type fracture of the atlas. E. Fractures of the odontoid process and the pedicles (hangman's fracture) of the axis.

A. Arrangement of A. Arrangement of the deep muscles of the deep muscles of the back. B. Lateral the back. B. Lateral view of the skeleton view of the skeleton showing the line of showing the line of gravity. gravity. Because the Because the greater part of the body greater part of the body weight lies anterior to the weight lies anterior to the vertebral column, the vertebral column, the deep muscles of the back deep muscles of the back are important in are important in maintaining the normal maintaining the normal postural curves of the postural curves of the vertebral column in the vertebral column in the standing position.standing position.

MusclesMusclesTrap, Lat dorsi, Lev scap, Rho maj & min

Serratus posterior sup & inf

DeepSuperficial Vertically Running Muscles

Intermediate Oblique Running Muscles

Deepest MusclesInterspinalesIntertransversarii

Muscular triangles of backMuscular triangles of backAuscultatory Triangle

The auscultatory triangle is the site on the back where

breath sounds may be most easily heard with a

stethoscope. The boundaries are the latissimus dorsi, the

trapezius, and the medial border of the scapula.

Lumbar TriangleThe lumbar triangle is the site where pus may emerge from

the abdominal wall. The boundaries are the latissimus dorsi,

the posterior border of the external oblique muscle of the

abdomen, and the iliac crest.

Deep Fascia of the Back Deep Fascia of the Back (Thoracolumbar Fascia)(Thoracolumbar Fascia)

The lumbar part of the deep fascia is situated in the interval

between the iliac crest and the 12th rib. It forms a strong

aponeurosis and laterally gives origin to the middle fibers of the

transversus and the upper fibers of the internal oblique muscles of

the abdominal wall

Medially, the lumbar part of the deep fascia splits into three

lamellae. The posterior lamella covers the deep muscles of the back

and is attached to the lumbar spines. The middle lamella passes

medially, to be attached to the tips of the transverse processes of

the lumbar vertebrae; it lies in front of the deep muscles of the back

and behind the quadratus lumborum. The anterior lamella passes

medially and is attached to the anterior surface of the transverse

processes of the lumbar vertebrae; it lies in front of the quadratus

lumborum muscle.

Blood Supply of the BackBlood Supply of the Back Arteries

◦ In the cervical region, branches arise from the occipital artery, a branch of the external carotid; from the vertebral artery, a branch of the subclavian; and from the deep cervical artery, a branch of the costocervical trunk.

◦ In the thoracic region branches arise from the posterior intercostal arteries.

◦ In the lumbar region branches arise from the subcostal and lumbar arteries.

◦ In the sacral region branches arise from the iliolumbar and lateral sacral arteries, branches of the internal iliac artery.

Veins◦ The veins draining the structures of the back form plexuses extending along

the vertebral column from the skull to the coccyx.

◦ The external vertebral venous plexus lies external and surrounds the vertebral column.

◦ The internal vertebral venous plexus lies within the vertebral canal but outside the dura mater of the spinal cord.

Lymph Drainage of the Lymph Drainage of the BackBack

The deep lymph vessels follow the veins and drain into

the deep cervical, posterior mediastinal, lateral aortic,

and sacral nodes.

The lymph vessels from the skin of the neck drain into

the cervical nodes,

from the trunk above the iliac crests drain into the

axillary nodes, and those

from below the level of the iliac crests drain into the

superficial inguinal nodes

RelationRelation

Vertebrae Spinal Segment

Cervical Add 1

Upper thoracic Add 2

Lower thoracic (T7 to 9) Add 3

Tenth thoracic L1 and 2 cord segments

Eleventh thoracic L3 and 4 cord segments

Twelfth thoracic L5 cord segment

First lumbar Sacral and coccygeal cord segment

Posterior views of vertebral bodies in the

cervical and lumbar regions showing the

relationship that might exist between the

herniated nucleus pulposus and the spinal

nerve roots. Note that there are eight

cervical spinal nerves but only seven

cervical vertebrae. In the lumbar region,

for example, the emerging L4 nerve roots

pass out laterally close to the pedicle of

the fourth lumbar vertebra and are not

related to the intervertebral disc between

the fourth and fifth lumbar vertebrae. E.

Pressure on the L5 motor nerve root

produces weakness of dorsiflexion of the

ankle; pressure on the S1 motor nerve

root produces weakness of plantar flexion

of the ankle joint.

SPINAL CORD INJURY WITHOUT RADIOLOGICAL ABNORMALITY:

‘SCIWORA’

This is particularly liable to occur if the vertebral canal is

abnormally narrowed, usually by osteoarthritic changes.

Surface Surface anatomyanatomy

Surface Surface anatomyanatomy

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