Nervous System Anatomy: Neuron Neuron Soma Dendrites Axon Axolemma Axoplasm Axon Terminal Synaptic End Bulb Axon Hillock Trigger Zone.

Nervous System Anatomy: Neuron

• Neuron Soma Dendrites Axon

Axolemma Axoplasm

Axon Terminal Synaptic End Bulb Axon Hillock

Trigger Zone Schwann Cell Myelin Sheath Node of Ranvier

Nervous System Anatomy: Spinal Cord

• Gray Matter• White Matter• Meninges

Dura Mater (Outer) Subdural Space

Arachnoid Mater Subarachnoid

Space Denticulate

Ligaments Pia Mater (Inner)

Nervous System Anatomy: Spinal Cord

Nervous System Anatomy: Spinal Cord

Nervous System Anatomy: Spinal Nerves

• Plexuses Cervical

8 Nerve Pairs Brachial

8 Nerves Lumbar

5 Nerve Pairs Sacral

5 Nerve Pairs• Thoracic Nerves

12 Pairs• Coccygeal Nerves

1 Nerve Pair

Nervous System Anatomy: Spinal Column

• Horns: Gray & White, Anterior & Posterior• Commisures: Gray & White, Anterior & Posterior• Roots: Ventral & Dorsal• Fissures & Sulci: Ventral & Dorsal• Columns: Lateral, Anterior & Posterior• Central Canal

Nervous System Anatomy

• Ventral & Dorsal Ramus

• Rami Communicantes

Nervous System Anatomy

Nervous System Anatomy

Nervous System Anatomy

Cervical Plexus

• Most major nerves occur on both right and left sides

• Most major nerves carry both motor and sensory information, although they may be mostly one or the other

• Phrenic n. Innervates the diaphragm Emerges C3 - C5 Damage to the spinal cord

above this point causes respiratory failure

• Supraclavicular n. Deep to the platysma Innervates skin in the neck,

shoulder, & upper chest

Nervous System Anatomy

Brachial Plexus

• Axillary n. Innervates

deltoid & teres minor

• Suprascapular n. Innervates

supraspinatus & infraspinatus

Nervous System Anatomy

Brachial Plexus

• Radial n. Innervates extensors

of arm & forearm

• Median n. Innervates flexors of

forearm

• Ulnar n. Innervates flexors of

wrist & hand

• Musculocutaneous n. Innervates

coracobrachialis, biceps brachii, & brachialis

Nervous System Anatomy

Lumbar Plexus

• Genitofemoral n. Innervates skin over

genitals & thighs

• Ilioinguinal n. Innervates skin over

genitals & thighs

• Femoral n. Innervates flexors of

thigh & extensors of leg

• Saphenous n. Branch of the Femoral n. Innervates skin over

medial surface of leg

• Obturator n. Innervates adductors of

leg

Nervous System Anatomy

Sacral Plexus

• Pudendal n. Innervates muscles of

the perineum & skin of the genitals

• Sciatic n. Largest nerve in the

body Splits into tibial &

common peroneal nerves

Innervates hamstrings & adductors

• Tibial n. Splits into lateral &

medial plantar nerves Innervates

gastrocnemius, soleus & other lower leg muscles

Nervous System Anatomy

Sacral Plexus

• Common peroneal n. Splits into superficial &

deep peroneal nerves Also known as the

common fibular nerve Innervates tibialis

anterior, peroneus (fibularis) longus & brevis, & other muscles of the lower leg & foot

• Sural n. Formed from branches of

the Tibial & Common Peroneal nn.

Innervates skin of lower leg & foot

• Medial & Lateral Plantar nn.

Innervate muscles of the foot

Nervous System Anatomy

Branches of the Trigeminal Nerve(Cranial Nerve V)

• The trigeminal nerve is Cranial Nerve V

Largest cranial nerve, with three major divisions

Many branches that provide somatic sensory information from the head & face

Also has motor output to muscles of mastication

• Infraorbital n.• Supraorbital n.• Lingual n.• Mental n.

Nervous System Anatomy

• Sensory and motor fibers travel along “highways” (tracts) in the spinal cord

• Sensory and motor tracts are landmarks for diagnosis & treatment of spinal cord damage