Download The Back

The Back
To describe vertebral column in various regions
To describe lumbar fascia
To list back muscles
The vertebral column:
-Average length in the male is about 71
cm& in female about 61 cm
-The column constitutes the five known
regions:
Cervical; 7
Thoracic; 12
Lumbar; 5
Sacral; 5
Coccyx; 1
Measurements (male values):
-Cervical part: 12.5 cm. (17.5%)
-Thoracic: 28 cm. (40%)
-Lumbar: 18 cm. (25%)
-Sacrum and coccyx: 12.5 cm. (17.5%)
Curvatures:
Primary curvatures (Flexion):
1- Thoracic; T2-T12
2- Pelvic; LS joint-coccyx
Secondary curvatures (Extension):
1- Cervical; C2-T2
2- Lumbar; T12-LS joint
Articulations of the vertebral column:
1- A series of synovial joints between the
vertebral arches (between articular
facets)
2- A series of secondary cartilagenous
joints
between
vertebral
bodies
(intervertebral discs)
Articulations between vertebral bodies:
-Bodies of adjacent vertebrae are held to
each other by fibrous discs which
strongly adhere these vertebrae to each
other
-Movements at these joints is slight
though summative movements permits
considerable range
-Ligaments supporting these joints are
the anterior & posterior longitudinal
ligaments
The intervertebral discs:
-These discs constitute about 1/4 the
length of the articulated vertebral
column
-They
vary
in
shape,
size,
and
thickness, in different parts of the
vertebral column, correspond with the
surfaces of the adhering bodies
-Each disc is composed of:
1- External annular fibrous part called
annulus fibrosus.
2- Central bulbous cartilage called
nucleus pulposus.
Prolapsed IVD:
-Herniation of nucleus pulposus into the vertebral canal compressing
on spinal nerve roots
Other ligaments in the vertebral column:
1
1- Ligamenta flava:
-Elastic ligaments
-Between adjacent laminae
2- Interspinous ligaments:
2
3
Connects adjacent spines
3- Supraspinous ligaments:
Connects spines tips
4- Ligamentum nuchae:
-Triangular fibrous sheet
4
-Attached to cervical spines & skull
-Divides the back of neck into two halves
Region
Main characters
Cervical
-Additional joints of Luschka
-Vertebral vessels passing through foramina transversaria
-Seven vertebrae, eight spinal nerves
-Spinal nerve passes superior to the pedicle of its
numerically corresponding vertebra
Thoracic
-Articulation by their bodies & transverse processes with
the ribs
-Spinal nerve passes inferior to the pedicle of its
numerically corresponding vertebra
-Mainly permit trunk rotation
Lumbar
-Giant, kidney shaped bodies
-Spinal nerve passes inferior to the pedicle of its
numerically corresponding vertebra
-Mainly permit trunk flexion-extensio & lateral flexion
4
Sacral
-5 sacral segments fuse with each other
-Articulates with lower limb bone (the hip)
-Nerves leave through anterior & posterior sacral foramina
5
Coccyx
Single triangular bone with no special feature
1
2
3
Kyphosis
Scoliosis
Overcurvature of thoracic vertebrae
Abnormal lateral curvature of VC
Surface localization of vertebrae:
Principles:
C2
C7
-The first palpable spine below the skull
is C2
T3
-The next most prominent is C7
-T3 lies level with scapular spine
T7
-T7 lies level with inferior scapular angle
T12
-L4 lies level with iliac tubercle
-T12 midway between T7 & L4
-Coccyx is the lower end
L4
Surface localization of lower end of spinal cord:
Principles:
-Localize T12 & L4 as previously mentioned
-Spinal cord terminates midway between them (L1-2)
-Lumbar puncture is done at L3-4 level
The thoracolumbar fascia:
-This strong fascial structure lies in the
posterior abdominal wall enclosing
muscular
compartments
&
gives
attachment to many other muscles.
-It is formed of 3 layers; anterior,
middle & posterior
-Anterior & middle layers are confined
to the abdomen
-The posterior one extends up in the
thoracic & cervical regions
-Quadratus
lumborum
is
enclosed
between the anterior & middle layers
-Erector spinae is enclosed between
the middle & posterior layers
Back muscles:
1- Extrinsic:
-Form superficial & intermediate layers
-Involved with movements of the upper limbs
and thoracic wall
-Innervated by anterior rami of spinal nerves
2- Intrinsic:
-They lie deep in position
-They support and move the vertebral column
and participate in moving the head
-Innervated by the posterior rami of spinal
nerves
Layer
1
Superficial
2
Intermediate
3
Deep
Muscles
-Trapezius
-Latissimus dorsi
-Levator scapulae
-The rhomboids
-Serratus posterior superior & inferior
1- Splenius group:
-Capitis
-Cervicis
2- Erector spinae group:
-Iliocostais (external)
-Longissimus (intermediate)
-Spinalis (deep)
3- Semispinalis group:
-Semispinalis
-Multifidus
-Rotators
The splenius muscles:
-The two muscles run from the spinous
processes upward and laterally
-Splenius capitis is a broad muscle
attached to the occipital bone and
mastoid process of the temporal bone
-Splenius cervicis is a narrow muscle
attached to the transverse processes of
the upper cervical vertebrae
-Together they draw the head backward,
extending the neck.
-Individually, each muscle rotates the
head to the same side of the contracting
muscle
The semispinalis muscles:
-These muscles begin in the lower
thoracic region and end by attaching
to the skull
-Crossing
between
four
and
six
vertebrae from their point of origin to
point of attachment.
-Semispinalis muscles are found in
the thoracic region (S. thoracis),
cervical region (S. cervicis) & attach
to the occipital bone (S. capitis).
-They are prime extensors of the
vertebral column
The suboccipital muscles :
1- Rectus capitis posterior minor
2- Rectus capitis posterior major
3
3- Superior oblique
1
4- Inferior oblique
-These
muscles
2
are
skull
extensors
-All are supplied by C1, posterior
ramus
4
Suboccipital triangle:
-2, 3 & 4 form the boundaries of this
triangle
-The triangle is roofed by splenius capitis
-Floor is the back of atlas
3
-Contents:
1- In the triangle:
-Vertebral artery
-C1 posterior ramus
2- Passing in the roof:
1- Occipital artery
2- Great occipital nerve (C2)
2
4
Plain Cervical
MRI
Suboccipital
C5
C3
MRI Cervical
C7
MRI Thoracic
SAP
L1
IAP
SAP
IAP
L5
Plain Lumbar
L1
L5
CT Lumbar
CT Upper sacrum