Surface anatomy of the back pdf - The back

Surface Anatomy

717

intervertebral

disc

anterior

medulla
oblongata

spinal cord
surrounded
by meninges

posterior

herniated
nucleus
pulposus

FIGURE 12.34

Sagittal MRI scan of the cervical part of the vertebral column. A herniated disc between the fifth and sixth verte

brae is shown. Note the position of the spinal cord and its meningeal coverings relative to the herniated disc. (Courtesy of Pait.)

region.

MRI is now largely replacing myelography or CT in this

to the dural sac can easily be demonstrated. The use of

The herniated fragment of the disc and its relationship

and the posterior longitudinal ligament (Fig. 12.34).

section and shows its relationship to the vertebral body

MRI easily defines the intervertebral disc on sagittal

boundaries of the anulus fibrosus.

Fragments of a herniated disc can be identified beyond the

natomy

face

The entire posterior aspect of the patient should be exam

runs down the back of the neck connecting the skull to the

a large ligament that

ligamentum nuchae,

covered by the

Cervical spines one to six are

bra (vertebra prominens).

seventh cervical verte

the neck (Fig. 12.35) is that of the

The most prominent spinous process that can be felt in

Cervical Vertebrae

nuchal groove.

the protuberance in the

on the skin in the midline, it can be drawn inferiorly from

the head and neck (Fig. 12.1). If the index finger is placed

The external occipital protuberance lies at the junction of

from above downward.

In the midline, the following structures can be palpated

at the side.

ined from head to foot, and the arms should hang loosely

Midline Structures

External Occipital Protuberance

spinous processes of the cervical

ebrae.

vert

The crest can

median sacral crest.

midline to form the

are fused with each other in the

spines of the sacrum

The

when the trunk is bent forward.

first thoracic vertebra; the others may be easily recognized

(Fig. 12.35). The most prominent spine is that of the

tebrae

lumbar ver

and the upper four

spines of all the thoracic

that runs down the middle of the back over the tips of the

The nuchal groove is continuous inferiorly with a furrow

Thoracic and Lumbar Vertebrae

compressed.

muscle, and against it the common carotid artery can be

can be palpated medial to the sternocleidomastoid

saignac)

of the sixth cervical transverse process (tubercle of Chas

anterior tubercle

from the lateral side in a thin neck. The

are short but easily palpable

transverse processes

The

Sacrum

718

CHAPTER 12

The Back

inferior angle
of scapula

superior angle of scapula

base of spine
of scapula

site of lower end
of spinal cord
at lower
border of
first lumbar
vertebra

seventh
cervical
spinous
process

first
thoracic
spinous
process

third
thoracic
spinous
process

seventh
thoracic
spinous
process

erector
spinae

intercristal plane
at level of fourth
lumbar vertebra

latissimus dorsi

FIGURE 12.35

The back of a 27-year-old man.

can be palpated

crest of the spine of the scapula

The

opposite the seventh thoracic spine (Figs. 12.1 and 12.35).

can be palpated

inferior angle

thoracic spine, and the

can be palpated opposite the first

superior angle

The

and traced medially to the medial border of the scapula,
which it joins at the level of the third thoracic spine
(Figs. 12.1 and 12.35).

inferior angle (Fig. 12.35).

which ends above at the superior angle and below at the

of the scapula forms a prominent ridge,

medial border

The

the 1st to the 7th ribs (Figs. 12.1 and 12.35).

ula and its associated muscles. The scapula lies posterior to

The upper lateral part of the thorax is covered by the scap

cyx can be palpated with a gloved finger in the anal canal.

behind the anus (Fig. 12.1). The anterior surface of the coc

in the groove between the buttocks about 1 in. (2.5 cm)

The inferior surface and tip of the coccyx can be palpated

groove between the buttocks.

cm) above the tip of the coccyx and beneath the skin of the

(epidural space) terminates. The hiatus lies about 2 in. (5

the lower end of the sacrum, and here the extradural space

is situated on the posterior aspect of

sacral hiatus

The

between the buttocks.

be felt beneath the skin in the uppermost part of the cleft

the second sacral vertebra and the middle of the sacroiliac

the latter lies beneath a skin dimple at the level of

posterior superior iliac

and behind at the

rior iliac spine

anterior supe

puncture. Each crest ends in front at the

and are used as a landmark when performing a lumbar

(Fig. 12.1). They lie at the level of the fourth lumbar spine

The iliac crests are easily palpable along their entire length

its associated gluteal muscles.

aspect of the upper part of the bony pelvis (false pelvis) and

The lower lateral part of the back is formed by the posterior

located.

ity of the spine of the scapula. It is subcutaneous and easily

forms the lateral extrem

acromion of the scapula

The

Lower Lateral Part of the Back

Iliac Crests

spine;

Coccyx

Upper Lateral Part of the Thorax

Scapula

Surface Anatomy

the vertebrae (Figs. 12.1, 12.9, and 12.35). They should be

The muscles are large and lie on either side of the spines of

tains the postural curves of the column, can be palpated.

controls the movements of the vertebral column and main

which mainly

posterior vertebral musculature,

The

buttocks.

the external occipital protuberance to the cleft between the

with reference to an imaginary line passing inferiorly from

Observe the back as a whole and compare the two sides

perior iliac spine.

vertebra (Fig. 12.7), which lies at the level of the posterosu

extends inferiorly to the lower border of the second sacral

cerebrospinal fluid,

with its

subarachnoid space,

The

lumbar spine.

(Fig. 12.7). In young children, it may extend to the third

the lower border of the spine of the first lumbar vertebra

in adults extends inferiorly to the level of

spinal cord

The

of the fifth lumbar spine.

anterosuperior iliac spine. The iliac tubercle lies at the level

surface of the iliac crest about 2 in. (5 cm) posterior to the

joint. The iliac tubercle is a prominence felt on the outer

719

Spinal Cord and Subarachnoid Space

Symmetry of the Back

examined with the flat of the hand. If they exhibit normal

persons usually exhibit a lateral thoracic curve to the left.

exhibit a lateral thoracic curve to the right; left-handed

involves extreme and prolonged muscular effort, usually

sons. Right-handed persons, especially those whose work

spines, reveals a slight lateral curvature in most normal per

ticular reference to the vertical alignment of the vertebral

Inspection of the posterior surface of the back, with par

lumbosacral angle.

meets the sacrum at a sharp angle, the

together have an anterior concavity. The lumbar region

(Fig. 12.2). The anterior surface of the sacrum and coccyx

in the thoracic region, and concave in the lumbar region

posterior surface is concave in the cervical region, convex

by inspecting the lateral contour of the back. Normally, the

can be examined

curves of the vertebral column

The

the muscular contraction.

produces a concavity of the vertebral column on the side of

harder than normal; it is also shorter than normal, which

tone, they are firm to the touch. A spastic muscle feels

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