Histology Guide

virtual microscopy laboratory

Chapter 6 - Nervous Tissue

Nervous system is specialized for the rapid communication of information from one region of the body to another.

Nervous system is divided anatomically into two major components:

Nervous system is divided functionally into two major components:

Although the CNS will be briefly examined, most of the emphasize will be on the PNS.

NEURON

The neuron is the structural and functional unit of the nervous system. However, non-neural cells (i.e., glial cells) provide support and protection in the CNS (oligodendrocytes, astrocytes, ependymal cells, and microglia) and the PNS (Schwann cells and satellite cells).

CENTRAL NERVOUS SYSTEM

The central nervous system (CNS) consists of the brain and the spinal cord.

Brain

Neurons have considerable variation in their size and shape. Because of the large size of human brains, the smaller rat brain is examined here.

slide
(Golgi's Stain)
slide
(Cresyl Violet)
(Nissl/Chromophil Substance)

Spinal Cord

The spinal cord functions primarily in the transmission of nerve signals between the brain and the body.

slide
(Cresyl Violet)
(Nissl/Chromophil Substance)

PERIPHERAL NERVOUS SYSTEM

The peripheral nervous system (PNS) consists of peripheral nerves and ganglia (clusters of nerve cell bodies).

Dorsal Root Ganglion

Dorsal root ganglia are clusters of nerve bodies of sensory neurons located alongside the spinal cord.

Sympathetic Ganglion

Sympathetic ganglia form long chains on either side of the spinal cord. They deliver information about stress, impending danger, and the fight-or-flight response.

Parasympathetic Ganglion

Parasympathetic nerves have their nerve cell bodies in small ganglia located within the organ they innervate.

Peripheral Nerve

Peripheral nerves contain the axons of both motor neurons and sensory neurons that connect with the spinal cord. They are surrounded by multiple layers of connective tissue.

slide
(H&E)
(longitudinal and cross-sections)
slide
(Masson's trichrome)

Sensory Nerve Endings

The nervous system has a variety of specialized receptors. Meissner's and Pacinian corpuscles are two that can be readily seen by H&E.

slide
(H&E)
(Meissner's and Pacinian corpuscles)
slide
(H&E)
(Meissner's corpuscle)
slide
(H&E)
(Pacinian corpuscle)
slide
(Masson trichrome)
(Pacinian corpuscle)