Peripheral nervous system Spinal nerves - Univerzita …anatomie.lf3.cuni.cz/centralni_prezentace/MisninervyLeRoy_eng.pdf · •Peripheral nervous system Spinal nerves Cranial nerves

Peripheral nervous system

Spinal nervesALR

© 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


Terminology

• neuroglia

• neuron

• nervous fiber

• nerve

• ganglion, nucleus


Cells of the nervous system

• neurons

• neuroglia


Neuroglia

• CNS:

▫ oligodendroglia

▫ astrocytes

▫ ependymal cells

▫ microglia

• PNS

▫ satellite cells

▫ Schwann cells



Neuron types

• multipolar

▫ motor fibers

▫ autonomic fibers

• pseudounipolar

▫ somatic sensory fibers

• bipolar

▫ retina, ggl of the vestibulocochlear nerve, olfactory epithelium

Multipolar neurons



Nervous fiber

• axon

• neurolemma

Schwann cells

▫ producing myelin

▫ not producing myelin


Types of fibers

• Afferent = sensory fibersoriginate on receptors in the periphery

▫ somatic sensory fibersexteroceptive and proprioceptive sensations

▫ visceral sensory fibers

• Efferent = motor fibers▫ somatic motor fibers

to skeletal muscles

▫ visceral motor fibersto smooth and cardiac muscles, glands


„Nerves“

• nervous fibers

▫ axon

▫ neurolemma (Schwann cells –

producing myelin or not)

• connective tissue

▫ endoneurium, perineurium,

epineurium

• vasa nervorum


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


Spinal segments

31 segments:

• C1-C8

• T1-T12

• L1-L5

• S1-S5

• Co


Macroscopy of the branching of

the spinal nerve



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 thespine

Sensory: skin in the rest of the body

Motor: epaxial muscles Motor: hypaxial muscles


Epaxial vs hypaxial muscles



Rami posteriores nervorum spinalium

C1: n. suboccipitalism. 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


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)



Plexus cervicalis – sensory branchesPunctum nervosum /Jonáš/

▫ n. occipitalis minor

▫ n. auricularis magnus

▫ n. transversus coli

▫ nn. supraclaviculares




Plexus cervicalis – motor branches



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


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




Paralysis of the diaphragm


Plexus brachialis

• truncus (trunk)superior (C4+C5+C6)medius (C7)inferior (C8+T1)

• fasciculus (cord)lateralismedialisposterior

• pars supraclavicularis• pars infraclavicularis



Brachial plexus injuries



plexus brachialis –

pars supraclavicularis

• n. dorsalis scapulae

• n. thoracicus longus

• n. subclavius

• n. suprascapularis

▫ incisura scapulae

▫ incisura spinoglenoidalis

• n. thoracodorsalis


n. thoracicus longus injury

„Scapula alata“


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


Entrapment syndromes

= compression of peripheral nerves in anatomical„tunnel“ regions, where they are suceptible to injury.

paresthesia, anesthesia in the area nervina ofthe injuried nerve palsy – according to the motor inervation of

the injuried nerve

Tinel‘s sign


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“


n. axillaris – C5-C6

• foramen humerotricipitale

-> „flat shoulder deformity“

– increased risk of luxation


n. medianus – C5-T1

• ligament of Struthers

• lacertus fibrosus

• canalis pronatorius

• canalis carpi

• -> „preaching hand“

ape hand deformity

• carpal tunnel syndrome



n. ulnaris – C8-T1

• claw hand• Froment‘s sign


Rami anteriores nervorum

thoracicorum

• nn. intercostales I-XI

• n. subcostalis


Intercostal nerves – motor branches

• 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

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II© 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“



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 Topography

n.Iliohypogastricus

m. Transversus abd.m. Obliquus int. abd.

Sup. to crista iliacaand lig. inguinale

n. Ilioinguinalis m. Transversus abd.m. Obliquus int. abd.

ScrotumLabia majora

Canalis inginalis

n. genitofemoralis

Through m. psoasmajor

r. Genitalis n. genitofemoralis

m. Cremaster ScrotunLabia majora

r. Femoralis n. genitofemoralis

Inf. to lig. inginale Lacuna vasorum

n. Cutaneusfemoris lateralis

Lateral part of thethigh

Lacuna musculorum

n. Femoralis m. IliopsoasAnterior group ofthe thigh

rr. Cutanei ant. femorisn. Saphenus

Lacuna musculorumTrigonum femoraleCanalis adductorius

n. Obturatorius Medial group of thethigh

Medial part of thethigh

Canalis obturatorius


Palsies

• n. femoralis

• n. obturatorius: weakened adduction and medial rotation(pregnancy)

• n. cutaneus femoris lateralis: meralgia parestetica


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



Plexus coccygeus S5-Co

• Motor: helps in the inervation of the pelvic floor

• Sensory: nn. anococcygei

(hurts in coccygeal fractures)


Areae radiculares

Areae nervinae



Documents

Peripheral nervous system Spinal nerves - Univerzita …anatomie.lf3.cuni.cz/centralni_prezentace/MisninervyLeRoy_eng.pdf · •Peripheral nervous system Spinal nerves Cranial nerves