Nerves of cervical and thorasic region

 The nervous system is the part of
an animal's body that coordinates the
voluntary and involuntary actions of the
animal and transmits signals between
different parts of its body.It consists of brain
spinal cord and nervs of various kinds At the
cellular level, the nervous system is defined
by the presence of a special type of cell,
called the neuron, also known as a "nerve
cell"

 In addition to the seven cervical vertebrae,
cervical anatomy features eight cervical
nerves (C1-C8) that branch off of the spinal
cord and control different types of bodily
and sensory activities.
 Each cervical nerve is named based on the
lower cervical vertebra that it runs between.
As an example, the nerve root that runs
between the second cervical vertebra and
the third cervical vertebra in the neck is
described as the C3 nerve.

 Branching off from the nerves in the spinal
cord, the cervical nerves are responsible for
relaying messages and ensuring functioning
to different body parts.
Different nerves and their funtion

 C1 and C2 (the first two cervical nerves) control the head.
 C3 and C4 help control the diaphragm (the sheet of muscle
that stretches to the bottom of the rib cage and plays an
important role in breathing and respiration).
 C5 controls upper body muscles like the Deltoids (which
form the rounded contours of the shoulders) and the
Biceps (which allow flexion of the elbow and rotation of
the forearm).
 C6 controls the wrist extensors (muscles like the extensor
carpi radialis longus, extensor carpi radialis brevis, and
extensor carpi ulnaris that control wrist extension and
hyperextension) and also provides some innervation to the
biceps.
 C7 controls the Triceps (the large muscle on the back of
the arm that allows for straightening of the elbow).
 C8 controls the hands.

 The thoracic spine is made up of the middle
12 vertebrae. These vertebrae connect to
your ribs and form part of the back wall of
the thorax (the ribcage area between the
neck and the diaphragm).

 The intercostal nerves are part of the somatic nervous
system, and arise from anterior divisions (rami anteriores;
ventral divisions) of the thoracic spinal nerves from T1 to
T11. The intercostal nerves are distributed chiefly to the
thoracic pleura and abdominal peritoneum and differ from
the anterior divisions of the other spinal nerves in that
each pursues an independent course without plexus
formation.
 The first two nerves supply fibers to the upper limb in
addition to their thoracic branches; the next four are
limited in their distribution to the parietes of the thorax;
the lower five supply the parietes of the thorax and
abdomen. The 7th intercostal nerve terminates at
the xyphoid process, at the lower end of the sternum. The
10th intercostal nerve terminates at the umbilicus. The
twelfth (subcostal) thoracic is distributed to the abdominal
wall and groin.

 Unlike the nerves from the autonomic
nervous system that innervate the visceral
pleura of the thoracic cavity, the intercostal
nerves arise from thesomatic nervous
system. This enables them to control the
contraction of muscles, as well as provide
specific sensory information regarding the
skin and parietal pleura. This explains why
damage to the internal wall of the thoracic
cavity can be felt as a sharp pain localized in
the injured region. Damage to the visceral
pleura is experienced as an un-localized ache

 The anterior division of the first thoracic nerve divides into
two branches: one, the larger, leaves the thorax in front of
the neck of the first rib, and enters the brachial plexus;
the other and smaller branch, the first intercostal nerve,
runs along the first intercostal space, and ends on the
front of the chest as the first anterior cutaneous branch of
the thorax.
 Occasionally this anterior cutaneous branch is missing.
 The first intercostal nerve rarely gives off a lateral
cutaneous branch; but sometimes sends a small branch to
communicate with the intercostobrachial.
 From the second thoracic nerve it frequently receives a
connecting twig, which ascends over the neck of the
second rib. This nerve was first described by Kuntz in 1927.
There is considerable anatomic variation, but Kuntz nerve
may be present in 40-80% of the population.[1][2]

 The Upper Thoracic Nerves: 2nd-6th[edit]
 The anterior divisions of the second, third, fourth, fifth, and sixth
thoracic nerves, and the small branch from the first thoracic, are
confined to the parietes of the thorax, and are named thoracic
intercostal nerves.
 They pass forward in the intercostal spaces below the intercostal
vessels. At the back of the chest they lie between the pleura and the
posterior intercostal membranes, but soon pierce the latter and run
between the two planes of Intercostal muscles as far as the middle of
the rib.
 They then enter the substance of the Intercostales interni, and,
running amidst their fibers as far as the costal cartilages, they gain the
inner surfaces of the muscles and lie between them and the pleura.
 Near the sternum, they cross in front of the internal mammary
artery and Transversus thoracis muscle, pierce the Intercostales
interni, the anterior intercostal membranes, and Pectoralis major, and
supply the integument of the front of the thorax and over the
mamma, forming the anterior cutaneous branches of the thorax; the
branch from the second nerve unites with the anterior supraclavicular
nerves of the cervical ple

 Branches[edit]
 Numerous slender muscular filaments supply the Intercostales,
the Subcostales, the Levatores costarum, the Serratus posterior
superior, and the Transversus thoracis. At the front of the thorax some
of these branches cross the costal cartilages from one intercostal
space to another.
 Lateral cutaneous branches (rami cutanei laterales) are derived from
the intercostal nerves, about midway between the vertebræ and
sternum; they pierce the Intercostales externi andSerratus anterior,
and divide into anterior and posterior branches.
 The anterior branches run forward to the side and the forepart of the
chest, supplying the skin and the mamma; those of the fifth and sixth
nerves supply the upper digitations of the Obliquus externus
abdominis.
 The posterior branches run backward, and supply the skin over
the scapula and Latissimus dorsi.
 The lateral cutaneous branch of the second intercostal nerve does not
divide, like the others, into an anterior and a posterior branch; it is
named the intercostobrachia

 The Lower Thoracic Nerves: 7th-11th
 The anterior divisions of the seventh, eighth, ninth, tenth,
and eleventh thoracic intercostal nerves are continued
anteriorly from the intercostal spaces into the abdominal
wall; hence they are named thoraco-abdominal
nerves (or thoracicoabdominal intercostal nerves).
 They have the same arrangement as the upper ones as far
as the anterior ends of the intercostal spaces, where they
pass behind the costal cartilages, and between
the Obliquus internus and Transversus abdominis, to the
sheath of the Rectus abdominis, which they perforate.
 They supply the Rectus abdominis and end as the anterior
cutaneous branches of the abdomen; they supply the skin
of the front of the abdomen.
 The lower intercostal nerves supply the Intercostales and
abdominal muscles; the last three send branches to
the Serratus posterior inferior. About the middle of their
course they give off lateral cutaneous branches.

 These pierce the Intercostales externi and
the Obliquus externus abdominis, in the same line as
the lateral cutaneous branches of the upper thoracic
nerves, and divide into anterior and posterior
branches, which are distributed to the skin of the
abdomen and back; the anterior branches supply the
digitations of the Obliquus externus abdominis, and
extend downward and forward nearly as far as the
margin of the Rectus abdominis; the posterior
branches pass backward to supply the skin over
the Latissimus dorsi.
 The Lower Thoracic Nerves: 12th
 The anterior division of the twelfth thoracic
nerve (subcostal nerve) is larger than the others; it
runs along the lower border of the twelfth rib, often
gives a communicating branch to the first lumbar
nerve, and passes under the lateral lumbocostal arch.

 It then runs in front of the Quadratus
lumborum, perforates the Transversus, and
passes forward between it and the Obliquus
internus to be distributed in the same
manner as the lower intercostal nerves.
 It communicates with the iliohypogastric
nerve of the lumbar plexus, and gives a
branch to the Pyramidalis. It also gives off a
lateral cutaneous branch that supplies
sensory innervation to the skin over the hip.

Nerves of cervical and thorasic region

Nerves of cervical and thorasic region

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