Download Branches

Nervous
system
SHANDONG UNIVERSITY
Liu Zhiyu
一、Divisions of nervous system
Ⅰ) Central nervous system (CNS)
Telencephalon
Brain
Diencephalon
Cerebellum
Midbrain
Brain stem
Pons
CNS
Medulla oblongata
Spinal cord
Ⅱ) Peripheral nervous system (PNS)
Cranial n. (12 pairs)
Spinal n. (31 pairs)
PNS
Somatic nerve
Somatic sensory n.
Somatic motor n.
Visceral sensory n.
Visceral n.
Sympathetic part
Visceral motor n.
Parasympathetic part
cell body
Neurons
I. Essential strunctures
of nervous system
Dendrites
Axon
Nuroglia: glial cell
Ⅰ) Structural classification
Bipolar neuron
Pseudounipolar neuron
Multipolar neuron
central branch
peripheral branch
Ⅱ) Functional classification
Afferent (sensory) neuron
Efferent (motor) neuron Association neuron (interneuron)
Nerve fiber
myelinated nerve fiber
unmyelinated nerve fiber
Nerve
II、reflex
reflex arc
Reflex:
a reaction of the organism by the
nervous system in response to a stimulus
Reflex
receptor
arc: consist of 5 basic components
afferent neuron
centre
effector
efferent neuron
Spinal nerves
Formation:
each spinal nerve is formed by union of anterior and
posterior roots at intervertebral foramen
The anterior root contains motor fibers for
skeletal muscles.
The posterior
rootcontains sensory
fibers whose cell bodies
are in the spinal ganglion
Spinal nerves
Spinal ganglia
is an enlargement of the
posterior root near the
intervertebral foramen
which consist of the
bodies of pseudounipolar
neurons
Divisions of spinal nerves
:
cervical nerves 8对
thoracic nerves 12对
lumbar nerves 5对
sacral nerves :5对
coccygeal nerve : 1对
The fiber components of spinal cors
There are four types of fibers contained in the spinal n.
Somatic afferent (sensory) nerve fibers :
Visceral afferent (sensory) nerve fibers
Somatic efferent (motor) nerve fibers ：
Visceral efferent (motor) nerve fibers ：
branches of spinal nerves
Each
spinal n. is divided into 4 branches after leaving the
intervertebral foramen immediately
anterior branche
posterior branche
meningeal branch
communicating branc
posterior branche
anterior branche ：，
cervical plexus
branchial plexus
lumbar plexus
sacral plexus 。
二、cervical plexus

Formation ：
it consists of the
anterior rami of C1C4 nerves.

Branches：
Cutaneous branches
Muscular brnches
Branches
 Cutaneous branches:
Lesser occipital
Great auricular
Transverse nerve of neck
Supraclavicular nerves
They emerge around middle of
posterior border of
sternocleidomastoid, to supply skin of
neck and scalp between auricle and
external occipital protuberance

Muscular branches:
supply the deep muscles
of neck

Phrenic nerve arises
from the of C3-C5,
innervation to diaphragm;
Phrenic nerve

Sensory fibers supply
to pleurae, pericardium
and peritoneum of
diaphragm; usually
right phrenic nerve may
be distributed on live,
gallbladder and biliary
system.
二、 brachial plexus
Formation ：
Formed by anterior rami of C5C8 and T1 nerves
Position ：
Passes through the scalene
fissure (斜角肌间隙) to
posterosuperior of subclavian
artery, then enters the axilla
to form three cords(束) which
around the axillary atery.
Medial cord 、
Lateral cord
Posterior cord
二、 brachial plexus
Branches
Median nerve
Musculocutaineous nerve
Ulnar nerve
Axillary nerve
Radial nerve
Anterior branche of thoracic nerve
，

Intercostal nerves （T1-T11），
Subcostal
nerve（T2）
，。
Distribution:
intercostales
anterolateral abdominal muscles
skin of thoracic and abdominal
wall, parietal pleura and
peritoneum
Anterior branches of thoracic
nerves
The distribution of the anterior
branches of the thoracic n. is
segmental.
T2 Sternal angle
T4 Nipple
T6 Xiphoid process
T8 Costal arch
T10 Umbilicus
T12 Midpoint between
umbilicus and symphysis
pubis
四、lumbar plexus
Formation:
anterior rami of L1-L3,
a part of anterior rami of
T12 and L4
position ：lies behind the
psoas major and beside the
lumbar vertera
branches：
Femoral
Obturator
Cutaneous
Genitofemoral
Iliohypogastric
Ilioinguinal
Lateral femoral
Femoral n.
route：
Runs downward and
laterally between psoas
major and iliacus, passes
deep to inguinal ligament;
disribution
muscular branches--supplies anterior thigh
muscles (quadricep
肌,sartorius and pectineus),
Femoral n.
sensory branches--hip and knee joint, and skin
on anteromedial side of
thigh,
saphenous nerve is
distributed to skin of medial
side of leg and foot
Obturator


Route：
Enters thigh through
obturator foramen;
Distribution：
muscular branches--supplies medial group of
muscles of thigh,
obturator externus,
sensory branches--- skin
of medial side of thigh
Lateral femoral cutaneous

It arises from the lateral
border of the psoas
major and runs
inferolateral to enter the
thigh posterior to the
inguinal lig.,just medial
to the anterior superior
iliac spine. it distribute to
the skin over the lateral
aspect of the thigh.
Genitofemoral


It pierces the anterior
surface of the psoas
major and runs
inferiorly ,and divide into
femoral and genital
branches
The femoral branche
distribute to the skin
over the femoral triangle;
and the genital branche
distribute to the
scrotum(greater lip of
pudendum)
五、

sacral plexus
formation ：
formed by anterior rami of L4
and L5 spinal nerves (the
lumbrosacral trunk) and anterior
rami of sacral and coccygeal
nerves

Position:
lies in pelvic cavity,
anterior to sacrum and
piriformis
五、
sacral plexus
main branches
Sciatic nerve
Pudendal nerve
Superior gluteal n.
Inferior glureal n.
Sciatic nerve



Leaves pelvis through
infrapiriform foramen to
enter gluteal region,
runs inferiorly deep to
gluteus maximus, passing
midway between the greater
trochanter of femur and
ischial tuberosity to back of
thigh, lying deep to long
head of biceps femoris,
normally divided into tibial
and common peroneal
nerves just above popliteal
fossa;
Sciatic nerve

it innervates
semitendinosus

Semimembranosus

and biceps femoris

Tibial nerve
Decends through
popliteal fossa , then
runs inferiorly with
posterior tibial vessels
and dividing into medial
and lateral plantar
nerves behind the
medial malleolus;
supplies posterior
muscles of leg and knee
joint
Common peroneal nerve

Arises at apex of popliteal
fossa and follows medial
border of biceps femoris
and its tendon; passes
over posterior aspect of
head of fibula and then
winds around neck of fibula,
deep to peroneus longus,
where it divides into deep
and superficial peroneal
nerves,to supply the
anterior and lateral groups
m. of the leg.
Superficial peroneal
Deep peroneal