Download Peripheral nervous system Spinal nerves

Peripheral nervous system
Spinal nerves
ALR
© Anne LeRoy
30.9.2015
© Anne LeRoy 30.9.2015
© Anne LeRoy 30.9.2015
Parts of the nervous system
• Central nervous system
▫ Spinal cord
▫ Brain




Brain stem (medulla oblongata, pons, mesencephalon)
Cerebellum
Diencephalon
Telencephalon
• Peripheral nervous system
▫ Spinal nerves
▫ Cranial nerves
▫ Autonomic nerves
 Sympathetic
 Parasympathetic
© Anne LeRoy 30.9.2015
Terminology
•
•
•
•
•
neuroglia
neuron
nervous fiber
nerve
ganglion, nucleus
© Anne LeRoy 30.9.2015
Cells of the nervous system
• neurons
• neuroglia
© Anne LeRoy 30.9.2015
Neuroglia
• CNS:
▫
▫
▫
▫
oligodendroglia
astrocytes
ependymal cells
microglia
• PNS
▫ satellite cells
▫ Schwann cells
© Anne LeRoy 30.9.2015
© Anne LeRoy 30.9.2015
Neuron types
• multipolar
▫ motor fibers
▫ autonomic fibers
Multipolar neurons
• pseudounipolar
▫ somatic sensory fibers
• bipolar
▫ retina, ggl of the vestibulocochlear nerve,
olfactory epithelium
© Anne LeRoy 30.9.2015
© Anne LeRoy 30.9.2015
Nervous fiber
• axon
• neurolemma
Schwann cells
▫ producing myelin
▫ not producing myelin
© Anne LeRoy 30.9.2015
Types of fibers
• Afferent = sensory fibers
originate on receptors in the periphery
▫ somatic sensory fibers
exteroceptive and proprioceptive sensations
▫ visceral sensory fibers
• Efferent = motor fibers
▫ somatic motor fibers
to skeletal muscles
▫ visceral motor fibers
to smooth and cardiac muscles, glands
© Anne LeRoy 30.9.2015
„Nerves“
• nervous fibers
▫ axon
▫ neurolemma (Schwann cells –
producing myelin or not)
• connective tissue
▫ endoneurium, perineurium,
epineurium
• vasa nervorum
© Anne LeRoy 30.9.2015
Ganglia and nuclei
= collection of neuron cell bodies
ganglion: outside the CNS
- sensory (DRG)
- autonomic
- sympathetic
(tr. sympaticus)
- parasympathetic
(periphery)
nucleus: in the CNS
Dorsal root ganglion from a chicken embryo
© Anne LeRoy 30.9.2015
Spinal segments
31 segments:
• C1-C8
• T1-T12
• L1-L5
• S1-S5
• Co
© Anne LeRoy 30.9.2015
Macroscopy of the branching of
the spinal nerve
© Anne LeRoy 30.9.2015
© Anne LeRoy 30.9.2015
Posterior vs anterior rami
Rami posteriores
Rami anteriores
Doesn‘t form plexuses
Forms the major somatic plexuses
Both sensory and motor fibers
Both sensory and motor fibers
Sensory: skin medially close to the
spine
Sensory: skin in the rest of the body
Motor: epaxial muscles
Motor: hypaxial muscles
© Anne LeRoy 30.9.2015
Epaxial vs hypaxial muscles
© Anne LeRoy 30.9.2015
© Anne LeRoy 30.9.2015
Rami posteriores nervorum spinalium
C1: n. suboccipitalis
m. rectus capitis post. mj.
m. rectus capitis post. mi.
m. obliquus capitis sup.
m. obliquus capitis inf.
C2: n. occipitalis major
C3: n. occipitalis tertius
L1-L3: nn. clunium superiores
S1-S3: nn. clunium medii
© Anne LeRoy 30.9.2015
interauricular line
Rami anteriores
nervorum
spinalium
• Cervical plexus (C2-C4)
• Plexus brachialis (C5-T1)
• rami anteriores nn.
thoracicum (T1-T12)
• Pleus lumbalis (T12-L4)
• Plexus sacralis (L4-S1)
• Plexus coccygeus (S5-Co)
© Anne LeRoy 30.9.2015
© Anne LeRoy 30.9.2015
Plexus cervicalis – sensory branches
© Anne LeRoy 30.9.2015
Punctum nervosum /Jonáš/
▫
▫
▫
▫
n. occipitalis minor
n. auricularis magnus
n. transversus coli
nn. supraclaviculares
© Anne LeRoy 30.9.2015
© Anne LeRoy 30.9.2015
© Anne LeRoy 30.9.2015
Plexus cervicalis – motor branches
© Anne LeRoy 30.9.2015
© Anne LeRoy 30.9.2015
Plexus cervicalis – inervated muscles
• mm. scaleni ant. + med. – pl. cervicalis +
brachialis
• mm. infrahyoidei – ansa cervicalis prof.
• m. longus colli - pl. cervicalis + brachialis
• m. longus capitis
• m. rectus capitis ant. + lat
• m. sternocleidomastoideus + m. trapezius –
ansa Maubraci
© Anne LeRoy 30.9.2015
Plexus cervicalis – n. phrenicus
C3-C5
= both sensory and motor
motor: diaphragm
sensory: pleura mediastinalis + diaphragmatica,
pericardium, peritoneum parietale (partially),
thymus (Cruchet‘s nerve), gallbladder
© Anne LeRoy 30.9.2015
© Anne LeRoy 30.9.2015
© Anne LeRoy 30.9.2015
Paralysis of the diaphragm
© Anne LeRoy 30.9.2015
Plexus brachialis
• truncus (trunk)
superior (C4+C5+C6)
medius (C7)
inferior (C8+T1)
• fasciculus (cord)
lateralis
medialis
posterior
• pars supraclavicularis
• pars infraclavicularis
© Anne LeRoy 30.9.2015
© Anne LeRoy 30.9.2015
Brachial plexus injuries
© Anne LeRoy 30.9.2015
plexus brachialis –
pars supraclavicularis
•
•
•
•
n. dorsalis scapulae
n. thoracicus longus
n. subclavius
n. suprascapularis
▫ incisura scapulae
▫ incisura spinoglenoidalis
• n. thoracodorsalis
© Anne LeRoy 30.9.2015
n. thoracicus longus injury
„Scapula alata“
© Anne LeRoy 30.9.2015
© Anne LeRoy 30.9.2015
plexus brachialis –
pars infraclavicularis
• fasciculus medialis
▫
▫
▫
▫
n. ulnaris
n. cutaneus antebrachii med.
n. cutaneus brachii med.
n. medianus
• fasciculus lateralis
▫ n. musculocutaneus
▫ n. medianus
• fasciculus posterior
▫ n. axillaris
▫ n. radialis
• nn. pectorales
• n. subscapularis
© Anne LeRoy 30.9.2015
Entrapment syndromes
= compression of peripheral nerves in anatomical
„tunnel“ regions, where they are suceptible to
injury.
 paresthesia, anesthesia in the area nervina of
the injuried nerve
 palsy – according to the motor inervation of
the injuried nerve
Tinel‘s sign
© Anne LeRoy 30.9.2015
n. radialis C5-C8
• sulcus nervi radialis
• behind the head of radius
• canalis supinatorius (r. prof)
▫ Frohse‘s arcade
-> wrist drop
„Saturday night‘s palsy“
© Anne LeRoy 30.9.2015
n. axillaris – C5-C6
• foramen
humerotricipitale
-> „flat shoulder
deformity“
– increased risk of
luxation
© Anne LeRoy 30.9.2015
n. medianus – C5-T1
•
•
•
•
ligament of Struthers
lacertus fibrosus
canalis pronatorius
canalis carpi
• -> „preaching hand“
ape hand deformity
• carpal tunnel syndrome
© Anne LeRoy 30.9.2015
© Anne LeRoy 30.9.2015
n. ulnaris – C8-T1
• claw hand
• Froment‘s sign
© Anne LeRoy 30.9.2015
Rami anteriores nervorum
thoracicorum
• nn. intercostales I-XI
• n. subcostalis
© Anne LeRoy 30.9.2015
Intercostal nerves – motor branches
nn. intercostales VII-XII
• rr. musculares:
▫
▫
▫
▫
▫
▫
▫
▫
mm. intercostales
m.transversus thoracis
m. serratus post.
m. obliquus abdominis ext.
m. obliquus abdominis int.
m. rectus abdominis
m. transvertsus abdominis
m. pyramidalis
© Anne LeRoy 30.9.2015
Intercostal nerves – sensory branches
• nn. cutanei laterales
▫ rr. mammarii laterales
▫ nn. intercostobrachiales (IC-II)
• nn. cutanei anteriores (terminal branches of IC
I-VI)
▫ rr. mammarii mediales
• rr. pleurales et peritoneales
 „défense musculaire“
© Anne LeRoy 30.9.2015
© Anne LeRoy 30.9.2015
Plexus lumbalis T12-L4
• „ I, I Get Laid On Fridays“
•
•
•
•
•
•
n. Iliohypogastricus – T12-L1
n. Ilioinguinalis – L1
n. Genitofemoralis – L1-L2
n. cutaneus femoris Lateralis – L2-L3
n. Obturatorius – L2-L4
n. Femoralis – L2-L4
Nerve
Motor
Sensory
n.
Iliohypogastricus
m. Transversus abd.
m. Obliquus int.
abd.
Sup. to©crista
iliaca
Anne LeRoy 30.9.2015
and lig. inguinale
n. Ilioinguinalis
m. Transversus abd.
m. Obliquus int.
abd.
Scrotum
Labia majora
n.
genitofemoralis
r. Genitalis n.
genitofemoralis
Topography
Canalis inginalis
Through m. psoas
major
m. Cremaster
Scrotun
Labia majora
r. Femoralis n.
genitofemoralis
Inf. to lig. inginale
Lacuna vasorum
n. Cutaneus
femoris lateralis
Lateral part of the
thigh
Lacuna musculorum
n. Femoralis
m. Iliopsoas
Anterior group of
the thigh
rr. Cutanei ant.
femoris
n. Saphenus
Lacuna musculorum
Trigonum femorale
Canalis adductorius
n. Obturatorius
Medial group of the
thigh
Medial part of the
thigh
Canalis obturatorius
© Anne LeRoy 30.9.2015
Palsies
• n. femoralis
• n. obturatorius: weakened adduction and medial
rotation
(pregnancy)
• n. cutaneus femoris lateralis: meralgia
parestetica
© Anne LeRoy 30.9.2015
Plexus sacralis (L4-S4)
•
•
•
•
•
n. gluteus sup. – L4-S1
n. gluteus inf. – L5-S2
n. cutaneus femoris post. – S1-S3
n. ischiadicus – L4-S3
n. pudendus – S2-S4
n. pudendus
• Somatic motor:
▫ pelvic floor
▫ perineal muscles
• visceral motor
▫ corpora cavernosa
▫ corpora spongiosa
• sensory
▫ perianal region
▫ scrotum/labia majora
▫ penis/clitoris
• Topography
▫
▫
▫
▫
foramen infrapiriforme
foramen ischiadicum minus
fossa ischioanalis
canalis pudendalis Alcocki
© Anne LeRoy 30.9.2015
© Anne LeRoy 30.9.2015
© Anne LeRoy 30.9.2015
Plexus coccygeus S5-Co
• Motor: helps in the inervation of the pelvic floor
• Sensory: nn. anococcygei
(hurts in coccygeal fractures)
Areae radiculares 
Areae nervinae 
© Anne LeRoy 30.9.2015
© Anne LeRoy 30.9.2015