Peripheral Nervous System

(nervous Tissue)

September 23, 2009

Spinal cord, DRG, Sympathetic and Parasympathetic Ganglia

Netter pl. 154

Dorsal horns: Interneurons

Ventral horns: Motor neurons

Lateral horns:

Sympathetic neurons Parasympathetic (S2-4) neurons

DRG: Sensory (pseudounipolar) neurons

Autonomic ganglia: Post ganglionic neurons with unmyelinated axons. Sympathetic: paravertebral ganglia Parasympathetic: In organs

X (vagus)

IX

parasympathetic

Somatic motor

sensory

Sympathetic: pre- & post-ganglionic fibers

Pelvi splanchnic (parasympathetic)

#65 Spinal cord and DRG

Ventral horn

Lateral horn

Dorsal horn

Dorsal root ganglion (DRG)

65-1N, Trichrome65-2, H&E65-1, Trichrome

Ventral median fissure

Dorsal median sulcus

Motor neurons, glial cells and neuropil

Glial cells

Neuropil

Dorsal root ganglion

65-165-1N65-2

Autonomic Nervous System(only several points relevant to today’s histology lab)

• Consists of sympathetic and parasympathetic divisions.• Is a two fiber system consisting of

– preganglionic myelinated fibers and postganglionic unmyelinated fibers.

– preganlionic fibers make synaptic contacts with postganglionic neuron cell bodies in respective ganglia.

• Sympathetic ganglia are arranged alongside the vertebral column , forming a chain (chain or collateral ganglia)

• Parasympathetic ganglia are located near or within the target organ (peripheral or terminal ganglia).

• Preganglionic neuron cell bodies are located:– In sympathetic division, in the spinal cord (T1 – L2 or 3).– In parasympathetic division,

• In the nuclei of CN III, VII, IX, and X• In S2, S3 and S4 of the spinal cord

Spinal cord, DRG, Sympathetic and Parasympathetic Ganglia

Netter pl. 154

Dorsal horns: Interneurons

Ventral horns: Motor neurons

Lateral horns:

Sympathetic neurons Parasympathetic (S2-4) neurons

DRG: Sensory (pseudounipolar) neurons

Autonomic ganglia: Post ganglionic neurons with unmyelinated axons. Sympathetic: paravertebral ganglia Parasympathetic: In organs

X (vagus)

IX

parasympathetic

Somatic motor

sensory

Sympathetic: pre- & post-ganglionic fibers

Pelvi splanchnic (parasympathetic)

#74 Sympathetic ganglion cells

#75 Parasympatheic ganglion cells(in Seminal vesicle)

#250 Parasympatheic ganglion cells in vaginal wall

Sensory and Autonomic Ganglia (cells) (DRG Parasympathetic)

Sensory and Autonomic Neurons (DRG) (Parasympatheitc)

#29 Parasympathetic ganglia

#155

#68 Nerve bundle in transverse section

Epineurium

Perineurium

#67 Peripheral nerve

#67 Longitudinal and Transverse Section of P. Nerve

Axon

Schwann cell membrane

A Schwann cell myelinate one axon

A Schwann cell wraps around several unmyelinated axons

#71-2A Motor end plate

Terminal bouton

#71-1A Neuromuscular spindle (junction)stretch receptor

Intrafusal fibers

#71-1B